Eliot Silverman

Eliot Silverman

Thursday, June 14, 2012

How Your Car Can Start On Fire

I’m sure you realize that you should not smoke while refueling your car.  Obviously a lit cigarette, or cigar, could ignite gas fumes.  There are two more ways you can inadvertently start a fire while refueling your car.  Please don’t try this at home or away from home.
When you are getting gas, some of the fumes escape into the atmosphere.  Even with those rubber seals you see on the gasoline nozzle, when you fill up your car some gas fumes escape and are very dangerous.  Liquid gas doesn’t want to burn, but gas as a vapor is very volatile. 
First way to start a fire:
Shell Oil Company recently issued a warning after three incidents in which a cell phone ignited gasoline fumes during refueling.
In one case the phone was left on the trunk during fueling.  It rang, started a fire and destroyed the car.  In another case, an individual suffered sever burns to the face when fumes ignited as they answered a call while refueling their car.  In a third case, an individual suffered burns to their thigh and groin as fumes ignited when the phone, which was in their pocket, rang while they were refueling their car.
Since a cell phone can start a fire, you should always leave it in the car, or turn it off when you refuel your car
Second way to start a fire:
Static electricity can start a fire.  There were 28 fires which began when the vehicle was re-entered or the nozzle was touched during refueling.  Some of the damages were extensive to the car and to the customer.  17 fires occurred before, during or immediately after the gas cap was removed and before fueling began.  To eliminate static electricity you must touch a metal part of your car. 

In summary:
Leave your cell phone in your car, or turn it off when you get gas.
Don’t re-enter your vehicle while getting gas.
When you get out of your car, touch any metal part of your car before you remove the gas cap.

Wednesday, June 6, 2012

That Darn Pesky "Check Engine Light"

Check Engine Light
The computer’s function is to minimize pollution. It has many sensors and solenoids it can actuate (cause to turn on and off) to monitor, adjust and fine tune your car to minimize its pollution.  When there is a problem with a component in the computer control system, the computer illuminates the “Check Engine” light or it illuminates the “Picture” of an engine.  For the rest of this article, I’m going to refer to these lights as (check engine light) CEL.

When you see the CEL on there is a problem.  I shake my head, and quiver when I hear a customer say, “The last mechanic said there was nothing wrong with my car.” If there was nothing wrong, the light would be off!  I am also amazed when I’m told by a customer that the last mechanic said they did not need to repair the problem.  Later you will know why this is a bad, bad idea.

When a car is here because the CEL is on I use a tool called a  “Scanner”  to connect to your computer.  One of the displays on my scanner is a number which is referred to as a code.   This first step is referred to as “Pulling a Code.”  Each problem for which your computer turns on the CEL has an associated number or “Code.”  Pulling a code does NOT tell me what part is bad- it tells me what area in the computer control system is/was malfunctioning.  I then print out a diagnostic chart related to this code, and I print out an electrical schematic for the problem area.  With these two print outs, and some other diagnostic tools, I can diagnose your computer system’s problem.  Most of computer diagnostics take between 30 and 45 minutes.

Three Possibilities When Your CEL Is On:
1.        The problem will affect performance.  For example, if your ignition coil went bad your car to run rough.
2.       The problem will NOT affect performance.  For example a bad gas cap allows the gasoline fumes from the gas tank to leak into the atmosphere.  A bad gas cap does not affect performance but it does pollute the air.
3.       The part which is bad will not affect performance, but left unchecked, it will cause another part to go bad.  For example, a bad oxygen sensor, on most cars, will not affect performance, but if it went bad and you left it on your car it will cause the catalytic converter to go bad.  Replacing the oxygen sensor when goes bad saves you a lot of money. 

Here’s another reason to repair a part that will not affect performance
Let’s say your last mechanic said the CEL is on because of a bad gas cap.  You choose not to replace it since it will not affect performance, nor will it cause any problem to any other part in your car.  That is correct….. but, three months later the oxygen sensor goes bad.  You don’t know it went bad since the computer does not have a ‘second’ CEL, nor can it make the CEL get brighter to inform you that another part went bad.  By the time your car is not running well, and you bring it in for repairs, you’ll need to replace the oxygen sensor and the catalytic converter.  Therefore, not replacing an inexpensive part, cost you hundreds of extra dollars in repairs.

Can The State of Illinois Make Me Fix MY Car?
Cars 1996 and newer need to have an emission inspection every two years.  These inspections, to be official, can only be done by a State of Illinois Emission Center, and you may only go for an inspection after you receive a notice from the State of Illinois.  If you pass the inspection, the test center notifies the Secretary of State, and your license plate is renewed. 

If your CEL is on, you’ll fail the emission test, and the State will not renew your license plate until you repair the car or they issue you a waiver.  Basically, waivers are only issued after you have spent money trying to repair you car. 

Thursday, May 31, 2012

How your A/C System works

At ambient temperatures a/c refrigerant is a gas.  Years ago cars used r-12, commonly know as Freon.   They stopped using r-12 because it eroded the ozone layer in the atmosphere.  Freon has been replaced by r-22, also known as Suva. 
When you turn on the a/c system, through a relay, and sensors the compressor clutch “Locks up” and the a/c compressor turns.   Suva enters the compressor as a gas, and comes out as a high temperature liquid.  By compressing the gas into a liquid the temperature goes up to around 250 degrees Fahrenheit.  The liquid leaves the compressor, travels through an aluminum line and goes through a “Condenser.”   The condenser looks like, and acts exactly like a radiator.  Outside air goes through the condenser and cools the refrigerant inside the condenser.  The refrigerant exits the condenser as a liquid and close to ambient temperature.   
The cool liquid refrigerant travels through another aluminum pipe, through an expansion valve, into the evaporator.  The expansion valve allows the liquid to ‘expand’ and become a gas.   When the liquid refrigerant expands and becomes a gas, its temperature decreases to just above 32 degrees Fahrenheit. 
The evaporator is another radiator.  It looks like a radiator, but is much smaller, and it is generally located behind/near the glove box.  The refrigerant enters the evaporator at around 32 degrees Fahrenheit, cooling the evaporator.  When you turn the a/c on the fan blows air across the fins of the evaporator cooling this air; hence you get cool air.  The hot air blowing across the evaporator heats the refrigerant in the evaporator.  Radiators/evaporators are also known as heat exchangers.  The air blowing across the evaporator is cooled, and the refrigerant inside the evaporator is warmed; hence heat is exchanged.
Hot air contains a lot of moisture.  As the evaporator cools this moist air, water condenses out, and is drained under the car.  When the a/c is on, and you are standing still, you will see a small puddle of water under your car.
If the refrigerant was below 32 degrees the water would freeze onto the evaporator, restrict air flow through it, and you would get diminished cooling.
If the drain in the evaporator gets clogged, the condensed water drains inside the car, and the carpeting on the front passenger seat gets very wet.  This is generally fixed by using a coat hanger to unclog the drain.
The refrigerant leaves the evaporator as a warm gas.  Through another aluminum pipe the refrigerant travels to an accumulator/dryer.  A dryer is used since water combined with refrigerant creates hydrochloric acid. Obviously acid is undesirable to the system. 
Through the last aluminum tube the refrigerant (still a gas) leaves the accumulator/dryer and goes back to the a/c compressor completing the a/c cycle.
A/C Compressor:
The front of the compressor has a clutch, and the clutch is turned by a belt.  When the a/c is off, the clutch turns, but the a/c compressor doesn’t turn.  When the a/c is turned on, an electrical current goes to the clutch, locking it up to the compressor so that the compressor turns.

High Pressure Sensor
This sensor is located between the a/c condenser and the evaporator.  Here the refrigerant is a high pressure liquid.  If the pressure exceeds the manufacturer’s maximum allowable pressure, the senor “Opens” and stops the flow of electricity to the a/c clutch.  When this sensor “Opens” the a/c clutch Is de-energized and the a/c compressor stops turning; hence the pressure goes down.  This is a safety device which prevents the system from “blowing up.”

Low Pressure Sensor:
This sensor is located between the evaporator and the a/c compressor.  If the pressure is too low, it “Opens” and stops the flow of electricity to the a/c clutch.  When this happens the a/c compressor stops turning.  This is a safety device which prevents the compressor from turning when there is not enough refrigerant/oil in the system to properly lubricate the compressor.

Aluminum Lines:
Aluminum lines have one problem… Aluminum parts sometimes corrode together.  If they did not corrode together, life is good and then they easily come apart.  However; if the aluminum parts corrode together they cannot be normally separated, and I need to replace both parts. 

For example, I had a Honda with a hole in the aluminum line between the condenser and the compressor.  The aluminum line corroded together with the condenser.  When I removed the line from the condenser, there where no threads left in the condenser to use to reconnect a new aluminum line.  I need to replace the condenser.  In this case an inexpensive repair became a very expensive repair.  Unfortunately I cannot tell ahead of time if the parts have corroded together or not corroded together.

Your a/c system is unique in that it never needs maintenance.  It is a closes system that continually recycles the refrigerant and the oil.  Oil is used to lubricate the a/c compressor.  Without this oil the compressor would seize-up.
If you have any questions please e-mail them to me at eliotsauto@aol.com
My web site is http://www.eliotscompleteautorepair.com/

A/C System

A/C system
Your a/c system is self contained and does not need maintenance.  If the air comes out cold, you are done, and you don’t have to worry about this system.  If the air comes our cool, or warm there are two possible problems with the system.

Why Doesn’t My A/C Work?
First possibility: The system may not have enough a/c refrigerant to enable a/c compressor to engage.  Under the best of circumstances an a/c system slowly loose its refrigerant.  It takes somewhere around 7 years for a perfectly good a/c system to leak enough refrigerant such that the compressor will not start when you try to get cold air.  The oil which lubricates the a/c compressor floats in the refrigerant.  As the refrigerant leaks out, the oil leaks out.  If the compressor engaged when there was inadequate amount of refrigerant, the compressor would not be properly lubricated, and it would seize-up.  To prevent this from happening, a pressure sensor prevents the a/c compressor from running when you are low on refrigerant.  

On a side note, to keep the compressor lubricated in the winter, the computer turns the compressor on and off. 

Also, when you turn on the “defrost,” the a/c system automatically turns on.  The air first goes through the a/c coils in order to “dry-out” the air, and then the air is heated by the heating coils so that it can evaporate the condensation on the windshield.

Second possibility:  The system is full of refrigerant, but due to an electrical problem, the a/c compressor does not turn on.   For example, you could have a bad button (on the dash), bad relay, bad fuse, bad wire, or a bad sensor. 

How Do I Diagnose a “Non-Operating A/C System?
I start by connecting my A/C gauges to your car.  If the lower pressure gauge indicates good pressure (oddly enough good pressure in ‘psi’ is equal to room temperature) then the car is full of refrigerant.  If I read good pressure but the a/c compressor does not engage, I know you have an electrical problem.

If the gauges indicate you don’t have any refrigerant, or a very low quantity of refrigerant then I add refrigerant and yellow dyed oil.  If the compressor engages, then I know the electrical system is good, and the system did not work because of “Low refrigerant.”  After I fill the system, I look for a refrigerant leak.  Looking through tinted yellow glasses I can see refrigerant leaking from your system.  Unfortunately, this only allows me to see “Big” leaks. 

A small leak takes 3 days to two weeks for the system to loose enough refrigerant such that the a/c compressor no longer engages.  Within days of the A/C no longer working, you need to bring your car back here so I can use my geeky yellow glasses to find the oil leaked.  The oil leaked at the same spot where the refrigerant leaked. Once I see which part leaked, I can give you a price to replace that part.

Why Do I Have to Refill MY A/C System Once a Year?
You may have a seal around the a/c compressor which shrinks when the temperature gets cold (winter) and allows the refrigerant to leak out.  When it is warm outside (summer) the seal expands and no longer allows the refrigerant to leak.  You fix this by replacing the a/c compressor, or you refill the system every summer.

Why Shouldn’t I Refill the A/C System in the Winter?
If you wait weeks before bringing your car back, the yellow dye with disappear and I will not know form where the refrigerant leaked.  It is for this reason that I hesitate refilling the a/c system in the late fall, winter, or early spring.  If it refill the system, and you don’t use it for a month, the refrigerant may have leaked out and you didn’t know it since you did not use it.  Months go by before you realize the a/c leaked, and by then I cannot see any trace of the yellow oil.

Thursday, May 10, 2012

How Do I Know If I Need a Brake Inspection or a Brake Job??

Brakes turn the energy of motion into heat.  In other words, when you want to stop the friction between the brake materials, and the brake rotors/drums (more on this later) creates heat.  The faster you go the more heat the brakes create for you to stop.
There are two types of brake systems, shoes and pads.  Shoes are the old system, and they are rapidly being replaced with pads.  Many years ago the government mandated that all cars have front brake pads.  Most of the cars I work on have  4 wheel brake pads. 

Brake shoes:
When you press the brake pedal you push brake fluid from the master cylinder through the brake lines into the wheel cylinders.  The pressure of the fluid in the wheel cylinders pushes two plungers outward which force the brake shoes to make contact with the inside of the brake drum.  The pressure/friction of the shoes on the drum causes your car to stop.   One of the biggest problems with this system is that the shoes don’t always make 100% contact with the brake drum.  When you stop braking springs retract the shoes and remove them from touching the brake drum. 
Brake Shoes and Drums

Brake Drums:
These rarely need replacing.  The brake shoes rub on the inside of the brake drum.  When the brakes are inspected, we measure the inside diameter of the drum.  If the diameter is too large (there is a federal limit which is different for every model) then we need to replace the drum.  If the drum is not round, you will feel the brake pedal pulsate, and we need to resurface the brake drum.  If the inside surface is flat, we do not need to resurface it when re replace the brake shoes.

Brake Pads:
When you brake you push brake fluid from the brake master cylinder through brake lines into the caliper.  In the caliper, the brake fluid pushes a piston outward forcing the ‘inside’ brake pad onto the rotor.  This is a litter difficult to explain, so please bear with me… “For every force there is an equal and opposite force.”  When the brake pad pushes against the rotor, the caliper is forced back, causing the ‘outside’ brake pad to make contact with the outside surface of the brake rotor.  This is called a sliding caliper.  Ideally, both pads exert the same force on the brake rotor.   A few manufacturers don’t use sliding calipers.  These manufacturers use a brake caliper with pistons on the inside and on the outside of the brake rotor.

Brake Caliper with One Piston

Brake caliper with two sets of pistons.  One set for the inside pad, and one set for the outside pad

 If a sliding caliper cannot slide, one pad is substantially more worn than the other pad, and you need a new caliper.  Another problem with brake calipers is that the piston does not retract when you stop braking.  This is also clear by noticing one brake pad being substantially more worn than the other brake pad.  When this happens, you need to replace the brake caliper.

Since it is important that the front left brakes and the front right brakes work exert the same forces, when one caliper is bad, it is generally recommended that both calipers be replaced. 

Brake pads are simpler than brake shoes, and they work significantly better.   Because brake pads are significantly better than brake shoes, the government mandates front brake pads. 

Most, if not all cars made in the last 10 years use front and rear brake pads.  The parking brake only engages the rear brakes, so manufacturers tried to incorporate a parking brake mechanism inside the rear calipers.  This system never worked well so they abandoned that system.  We now see a hybrid shoes/pads in the rear.  When you press the brakes, the rear brake calipers work exactly like the front brake calipers.  When you engage the parking brakes, you actuate a small set of shoes which are located inside the hub of the rear brake rotors. 

You can see the parking brake shoes since that
The brake rotor has been removed.

Brake Rotors:
The brake pads rub on the outside surfaces of the brake rotor.  Over time the brake rotor thins due to this friction.  There is a federal minimum thickness listed for all brake rotors.  This minimum thickness is different for each car model.  When brake pads are replaced the brake rotor needs to be flat.  This can be accomplished by resurfacing the brake rotor or by replacing the brake rotor.  When re resurface the brake rotor we use a brake lathe which thins the brake rotor and leaves a smooth finish.   Ten or more years ago, the brake rotors were thick enough such that we could resurface the rotors two or three times before they needed to be replaced.

I’d say, for the last 10 years, new brake rotors are rarely resurfaced since their thickness are slightly above the federal minimum.  The good news is that new brake rotors are significantly less expensive than they were 10 years ago.  In many cases the new brake rotors cost less than the cost of resurfacing the brake rotors.  Many times I have replaced the brake rotors, not because they were too thin, but because the new brake rotors were cheaper, or the same cost, as resurfacing them.

If the brake rotor ‘warps’ you will get a pulsation in the brake pedal. To eliminate the pulsation you either have the brake rotor resurfaced, or you have the rotors replaced.  This is felt in the brake pedal NOT in the steering wheel.  On a side note, if the steering wheel ‘pulsates’ it tends to indicate bad tires or an out-of-alignment problem.
This is a typical brake rotor

Brake Master Cylinder:
When You press the brake pedal you force brake fluid from the brake master cylinder to the four wheels. 

For safety purposes, the brake master cylinder is actually two master cylinders in one unit.  One part pushes brake fluid to the front brakes, and the other part pushes brake fluid to the rear brakes.  For example, if the brake line to the rear brakes leaks, you loose all rear braking, but you still have front brakes, and visa versa. 

Normally when you stop the brake pedal goes down to a point and stops moving.  Even with more pushing, the pedal does not go any close to the floor.  That is normal and good.  If you have a situation when you are at a stop and the brakes pedal slowly goes to the floor, you probably have a bad master cylinder or a brake fluid leak. 

Proportioning valves:
Without these valves, when you would begin to stop the front of the car would tend to “Dip.”  With these valves, the rear brakes engage a fraction of a second before the front brakes preventing the front end from dipping.  I have never had to replace one of these because they were bad.  I have replaced them because I could not remove the brake lines from them without doing damage.
     Pictorial -Notice the two chambers               A typical brake master cylinder

Brake Hoses and Brake Lines:
Brake lines are steel, and brake hoses are rubber.  The steel lines, after many years sometimes leak due to rust.  The rubber in the brake hoses rarely go bad, but when they do, the rubber cracks and break. If either the hose or line breaks it becomes obvious because the brake light comes on, your brake pedal goes to the floor, and if you wait long enough, the car will not stop as quickly normal.  This diminished braking is very obvious. 
         Brake hoses                                                 Brake line

If you have any questions about your brakes call me at 773 935 2400

Tuesday, April 24, 2012

Emission Controls

The goal of the emission control system is simple, minimize pollution.

PVC Valve
The first emission control device was the positive crankcase ventilation valve, also known as the PCV valve.  It was federally mandated in 1963.  During the compression stroke a small percentage of the raw air/fuel mixture squeezes between the pitons and the cylinder walls and goes into the crankcase.  This raw mixture of air and fuel is very polluting.  Before 1963 these gasses were vented into the atmosphere.  With a PCV valve, these raw gases are put back into the engine where they are burned.  This reduces pollution while marginally increasing gas mileage.

EGR Valve
In 1972 the government mandated “Exhaust Gas Recirculation” valves, also know as EGR valves.  This valve opens when the engine is warmed-up and turning faster than the idle speed.  It allows a predetermined amount of burnt gases to be recycled back into the intake.  Over 98% of the exhaust gases are inert since they were ‘burnt’ in a previous combustion event.  Nitrous oxide is the main component of “Smog” and is caused by high combustion temperatures.  Mixing raw air/fuel with inert gas from the EGR valve decreases the combustion temperatures, preventing (limiting) the production of nitrous oxides.

Catalytic Converter
In 1975 catalytic converters were introduced.  Catalytic converters are very effective means to reduce air pollution.  When you burn gas, you produce H20 (water), carbon dioxide (C02) and Carbon Monoxide (C0) and some gasoline remains unburnt (HC).  H20 and CO2 are desirable results of combustion, but HC and C0 are very polluting and therefore undesirable. The catalytic converter converts CO into CO2 and converts HC into H2O and C02.  Catalytic converters can be destroyed instantly with leaded gas.  When they were introduced, the gasoline manufacturers also introduced lead free gas. 

Oxygen Sensor
Oxygen sensors are used to fine tune the air fuel mixture.  The ideal mixture is 14.7 parts of air to one part of gasoline.  This ratio is called stochiometric.  A rich running car means there is too much fuel for the amount of air, and a lean running condition means there is too much air for the amount of gasoline.  A very rich or very lean running engine will ruin a catalytic converter.  To keep the engine close to stochiometric, manufacturers added sensors to measure the amount of air going into the engine.  Knowing how much air is going into the engine, the computer can add the proper amount of gasoline.  The Oxygen sensor is a feedback device which tells the computer if the mixture is too lean or too rich.  Since the oxygen sensor helps the computer maintain stochiometric mixture it reduces pollution and increases gas mileage.

EVAP System
The EVAP system was introduced around 1996.  This system is designed to prevent gas vapors from escaping into the atmosphere.  Gasoline in your gas tank naturally vaporizes.  In older cars this vapor was vented into the atmosphere.  Since 1996 these vapors are collected in a canister filer.  When you are moving above a predetermined speed, two valves open up allowing the vapors in the canister filter to vent into the engine where they are burnt.  This devise increases gas mileage and decreases pollution. 

Wednesday, April 18, 2012

Be Paid $538 per month or $6256 to Keep Your Car In

Sounds too good to be true, but it is…. Let me explain.
A few months ago my niece sent me an article which stated the average car on the road is about 11 years old.  This is a record.  The article hinted that this was due to the recession.  It is NOT because of the recession!   
Let’s get started…. Growing up in the 70’s my parents, who were middle class, bought a new car when their existing car had about 60,000 miles.  This wasn’t because they wanted the new features, or they liked car payments, or they just wanted a new car. They bought a new car because they had to.  The existing car was falling apart. Inside and outside everything was breaking. 
Since then the quality of cars as skyrocketed.  What I call revolutionary, not evolutionary quality improvement.  I opened my business in 1986 and I saw first hand the quality improvements. 
My 1993 Oldsmobile, with over 230,000 miles, ran like new – until an Audi rear ended my car – it was parked.  My 1996 Oldsmobile similarly runs like new and all I ever do is maintenance.
Cars made after 1995 were designed to run like new, with just regular maintenance, for over 200,000 miles.  This isn’t pie-in-the-sky praying, this is for real.  I see it every day.  Cars with over 100,000 miles are the new normal, not unusual.  I believe in a few years, cars with over 200,000 miles will be the new normal as well.
So how do you get paid $538 per month or $6256 per year NOT to buy a car?
Insurance on a new car is at least $600 more than insurance on a 6 year old car.  Cars over 6 years old, on average, cost $500 per year to keep in like-new condition.  Since you save $600 on insurance, it is like the insurance company is paying you $100.00 per year NOT to buy a new car.
Also, the average car payment is $438 per month.  Keeping your car is like the auto companies paying you $438 per month, or $5256 per year to keep your car.  These are real savings, but you must maintain your car.

Thursday, April 12, 2012

Anti Freeze, More Complex than you might think

Your Anti Freeze (also called ‘coolant’)
It has four jobs:
1.        It keeps the engine at a constant temperature
2.       It lubricates the water pump
3.       Cool the automatic transmission oil
4.       It provides heat for the heating vents.

For coolant (water) to work, it must be able to flow from the engine to the radiator and back.  Outside air passing through the radiator cools the ‘coolant’ inside the radiator. 

An anti freeze agent (ethyl glycol) was added to the coolant(water) to keep it from freezing.  Ethel glycol lowers the freezing point of water, which is important in the winter.  Additionally, it raises the boiling point of water, which is important in the summer.  Your water pump cannot pump steam so it is very important that the coolant doesn’t ‘boil.’

Your engine gets extremely hot from burning gasoline.  To maximize gas mileage, and reduce pollution, anti freeze needs to keep your engine at a predetermined temperature, normally 275 degrees Fahrenheit.   If the temperature of the anti freezes gets too hot, the air/fuel mixture will combust too soon, and if the temperature of the anti freeze is too low, the gas does not completely burn.

The temperature of the anti freeze is controlled with a thermostat.  Your car’s thermostat is NOT an on or off type of switch.  It can open up a little, or open up a lot depending upon how much cooling is needed.  Highway driving creates more heat than stop and go driving.

One of the reasons a car overheats is the thermostat does not open up or does not open up enough.  Either way, not enough coolant is allowed to pass through it to the radiator, so the coolant overheats.

If the thermostat stays open, the anti-freeze continuously circulates through the radiator, which means it takes a long time for the engine to heat up to its normal operating temperature.  This causes excess pollution, poor gas mileage, and increases the amount of time it takes for you to get heat out of the vents.

Some of the additives in your anti freeze lubricate the water pump and others prevent impurities from accumulating inside the radiator.  Many cars have engines made of cast iron and aluminum.  With two different types of metal in water (anti freeze), ions from one metal want to go to the other metal.  This causes pitting, and if the pitting gets very bad, the anti freeze escapes the engine through gaps created by this pitting.  Manufactures add a “Dielectric Inhibitor” to their anti freeze to prevent pitting.

A few years ago GM and others introduced a “Long Lasting” anti freeze.  The old standard anti freeze (green) is replaced every two years or every 24,000 miles which ever comes first.  GM’s long lasting anti freeze is colored ‘hot pink’ and Fords long lasting anti freeze is colored ‘yellow.’  Color is added to the anti freeze so we don’t confuse one with the other.  Long lasting anti freeze, we were initially told, is replaced every 5 years or 150,000 miles which ever comes first.  When long lasting anti freeze was introduced it was considerably more expensive then ‘regular’ anti freeze.  Now they cost me about the same.

Sounds good but…..  Under normal condition a small amount of water boils out of anti freeze.  It shouldn’t happen, but it does.  This will not create a problem with the old style green anti freeze.  However, if too much water boils out of long lasting anti freeze, the long lasting anti freeze solidifies inside the engine and radiator.  This prevents the flow of coolant through the engine and radiator causing the engine to overheat.  

The solid mass can be removed, but it is an expensive repair.  Years ago I met with a GM engineer and asked him about this problem. He said GM was aware of the problem, and to prevent this from happening, he said long lasting anti freeze should be changed every two years or every 24,000 miles which ever comes first. 

Monday, April 9, 2012

Transmission Oil

Transmission Oil
Transmission oil does two very important things.             
1.       Inside the torque converter it moves the power from your engine to your transmission.
2.       It lubricates your transmission.

Your transmission is the second most expensive part of your vehicle to replace.  The engine is the most expensive part to replace.  Oddly enough, I rarely replace engines, but I replace 6 to 8 transmissions each year.

It is in my professional opinion that you take good care of your transmission, and all you need to do is change the transmission oil.

Years ago there were two types of transmission oils.  Now it seems like there is a new one each month.   If your car was stuck on the side of the road, it would be okay to use the wrong to get you to the next exit.  As soon as possible, though, you need to have a mechanic flush out the old fluid and replace it with correct transmission oil.

The wrong transmission oil, in the short term, may cause your transmission to poorly change gears.  Years ago I did a pre-purchase inspection of a Honda.  The transmission had a slight hesitation changing gears.  Slight, but definitely noticeable.  I called my transmission rebuilder who had me check a few items on the transmission.  He told me he suspected the transmission had the wrong oil and suggested I remove the old oil refill the transmission with the correct transmission oil.  Sure enough, once I changed the oil, the transmission properly changed gears.  Luckily for the owner, I was told, the wrong oil would not cause abnormal wear and tear of the transmission.

In 1986, when I opened my repair shop, we changed the transmission oil by removing the transmission pan.  When the pan came down, about 3 to 4 quarts of oil came down with it.  Often making a big mess of my shirt and my shop floor.  Once the pan was removed I had access to the transmission oil filter which I changed before reassembling the pan and adding transmission oil.

Thanks to some mechanical genius, who saved many shirts and shop floors, we no longer change transmission oil this way.  I now connect my equipment to a transmission line which runs between the transmission and the radiator.  (Transmission oil is pumped to the radiator to cool it.  The anti freeze in the radiator and your oil never mix.  The transmission fluid has its own set of cooling coils inside the radiator.)  Once my equipment is connected to the transmission line, I start your car and the transmission oil is pumped into my equipment rather than the radiator. My equipment pumps an identical amount of oil back into the transmission. 

A transmission can hold up to 16 quarts of oil.  My newer equipment replaces 99% of the oil in your transmission.  The old way only replaced 3 to 4 of the oil in your transmission.

Some transmissions have an external transmission oil filter. These filters screw and unscrews just like an oil filter. 

Most manufacturers recommend changing the transmission oil every 36,000 miles or 3 years whichever comes first.  A few, very few, like VW recommend that you NEVER change the transmission oil.  Your owner’s manual is the best source for information about your car. 

Thursday, March 29, 2012

If I use regular oil (non synthetic) how often should I change my engine oil?

Until recently manufacturers and independent repair shops said you should change your oil and filter every 3,000 miles or 3 months whichever comes first.  Recently, manufacturers have stated that the oil should be changed every 7500 miles under “Normal” conditions.

This “Normal” condition statement, in my mind, is a winnie clause.  I say this because of how manufacturers define ‘Normal.”  “Normal Conditions:” engine at operating temperature (What does that mean?) at highway speeds, and in a dust free environment. 

“Severe” condition is defined as: stop and go driving, trips of less than 10 miles, city driving, or extreme heat or cold.

Think about those two conditions…. Where in the USA will you be able to drive in “Normal Conditions?”  I can’t think of any, and for sure NOT in Chicago.

If you drive your car almost anywhere in the USA you will be driving in “Severe” conditions.  Therefore, you should change your oil and filter every 3,000 miles.

In Chicago I recommend you change your oil every 3,000 miles or 3 months. 

Because dirt in your oil can cause severe wear, you are safer changing the oil and filter
too often rather than not often enough.
Your oil is your engine’s cesspool system.  The oil filter stores a limited amount of dirt.  Once you exceed the limit, the oil and dirt bypasses the filter allowing the dirt to cycle throughout your engine.  Nobody knows how much dirt is in the oil, and how quickly it accumulates.  When you get an oil, lube, filter change, mechanics do not inspect the oil filter- we don’t have the equipment to do so, nor would you want to pay for that inspection.  Therefore, we do not know if you really need a filter, or if you waited too long before it was changed.  To prevent severe wear and tear in your engine, you are much better off changing the filter too often rather than not often enough.

Every once in a while I get a car whose oil is rarely changed.  In these cases, the oil has solidified inside the engine.  There are small passageways the oil needs to flow through to properly lubricate your engine.  When the oil solidifies it will not flow through these passageways causing premature engine failure.

Some newer models have a “variable cam shaft.”  Using a variable cam, engineers have been able to increase horse power without increasing the size of your engine.  Oil is used to ‘vary the camshaft.’  If you don’t change your oil often enough, or you use the wrong viscosity oil, the passageways to the variable camshaft ‘plug’ and the shaft doesn’t “Vary.”  This causes the ‘Engine’ light to come on. 

Changing the oil does NOT unplug the passageways.  The only way I know to unplug them is to put a thin metal rod, like a pipe cleaner, through these passageways. Sounds easy, but it is very expensive, and sometimes not even possible.

If you use the proper viscosity oil, and change it on a regular basis, you prevent clogging, and premature engine failure.

Friday, March 23, 2012

Your Engine Oil

There are two basic types of engine oils-Regular and synthetic.  Synthetic oil can be used in all cars, but regular oil cannot be used in cars which require synthetic oil. 
There are two other factors which differentiate oil:
Viscosity:  viscosity is a measure of the oil’s ability to flow.  As the temperature drops, oil tends to thicken like molasses, and as the temperature rises, oil tends to thin-out like water.  You need oil to flow through your engine when it is zero degrees outside and when it is 100 degrees outside. 
Oil manufacturers added chemicals to their oil so the oil maintains a consistent viscosity through a wide range of temperatures.  Oil companies label their oils, such as 5W30 or 05W20 so you/me know the viscosity.  The automobile manufacturers require specific viscosity oils for their cars. 
The lower number refers to the ability of the oil to properly flow at low temperatures, and the high number represents the ability of the oil to properly flow at high temperatures.  It would have been nice if those numbers represented degrees Celsius or degrees Fahrenheit, but they do not.  In Chicago a “5” as the lower number is adequate all winter long.  In areas where the temperature gets well below zero, Valvoline makes a ‘0’ weight oil.  In Chicago a ‘30’ weight oil is adequate for our summers. 
For reasons not known to me, there are some cars which require 5W20 oils.  Even though the upper number is ’20,’ these oils are fine for Chicago summers.  The proper viscosity oil for car is always in the owner’s manual, and often found on the oil fill cap.  Most of the time, but not always, if your car needs synthetic oil it will say so under the hood.
The last of the equation is the version of the oil.  Oil companies have made tremendous advances in their oil.  When there is a change it is indicated by the letter following the viscosity range.  I don’t know the current letter.  I don’t need to know since I buy Valvoline oil and they always bring me the latest version.  The latest version can always be used in older cars, but you should not use older versions in newer cars.  If you buy oil from any respectable retailer you will be getting the latest and greatest version.  I point this out in the event a friend of yours offers you the oil which has been sitting on the shelf of his garage for the last 10 years.  This ten year old oil, may not be the best for your car.    
Other notes on oil:
The oil manufacturers add other chemicals to their oils.  They add a chemical which isolates water.  Without this additive the water would tend to cause rust inside your engine.  They add an anti-foaming agent.  Without this additive the oil would foam-up inside you engine.  This might sound cool, but your oil pump cannot pump foam, it can only pump a liquid.  And you would not be able to drive very long without being pumped insides your engine.  They have also added friction modifiers to increase gas mileage. 
Next week I will share with you why I recommend you change your ‘regular’ oil every 3,000 miles – and why the manufacturers might say something different, but add a weenie clause to their initial recommendation.