| Q: | FAQ 58: Timing Belts, Timing Chains | | A: | The task of a timing belt or timing chain is to connect the cam shaft (which opens and closes the valves) to the crank shaft (which pushes the pistons up and down) AND TO KEEP THEM IN COMPLETE SYNCHRONIZATION. When the camshaft stops turning because the timing belt slips or break, a valve will inevitably be left open. As the crankshaft continues to turn and push the pistons up and down, the piston can collide with the open valve and damage the valve or piston. When that happens, a timing belt replacement that would usually cost $250-350 has grown to a, "let's remove the head, fix all the bend and broken valves and let's pray none of the pistons are damaged because if they are, you will need a complete new engine which will start at $1000 and could grow to $3500-4500.".
Timing chain - often used on V-6 and V-8 domestic engines as well as some import engines. Mostly of the time, unless a chain guide breaks, these systems will last 125-150k miles. To see the slop the chain may have, pull all the spark plugs and remove the distributor cap. Then turn the engine over maybe 1/4 of a turn using the front crank bolt. Stop, then while watching the rotor, turn the engine the other way and watch the rotor for movement. Most good techs can "feel" and see the slop in the chain by this simple test.
When replacing the timing chain, never cut corners and replace the cam and crank seals, all of the timing chain guides and the tensioner. If you don't, you will go back into this same area to do the rest of the job in the very near future.
Timing belt - used in most overhead cam 4 and 6 cylinder engines, domestic and import. The belt is cogged on the underside and not only runs the cam shaft, but in some engines, can run a sprocket that runs the distributor, or the balance shaft or the water pump. Some cars even have two timing belts.
The time to replace the timing belt varies car maker to car maker, but I think most techs would agree that you need to change your timing belt no earlier than 60k and no later than 100k. Check your owners manual for specific information.
The cost to replace the timing belt depends on what else you do. All of the components inside the front covered area of the engine went the same miles, the belt, the cam and crank seals, maybe the water pump and for sure the belt tesioner. Replacing just the belt is just plain stupid. When you do that, you can be sure you will not make another 60k or 80k because something will go wrong, a seal will go bad and wipe out the new belt and you will have to do the entire job all over again.
Bid the basic components, the belt(s) and the labor, then pick a shop and then authorize the work. Tell them to call you with an updated estimate once they get inside. Plan on another $200-300 or so on top of the belt(s) and labor original estimate. Do it right and you will get the same mileage you got with the original belt, cut corners and you will pay to go back in there again . . . and again . . . and again . . .
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| Q: | FAQ : Brake fluid flush, why? | | A: | Years ago, when master cylinders cost $59 and the labor was $30 to change them, spending money trying to save or extend the life of your brake master wasn't a good idea. If you decided to flush the master cylinder once a year or every other year, the cost of the flush would exceed the cost of the repair. So why spend $35-45 two or three times to save a $90 repair job?
But today is quite different. Today with anti-lock brakes (ABS) the pump and master cylinder can cost $2,250 or more, depending if you have a GM or a Lexus. So if you agree that old dirty brake fluid will eventually cause brake component problems, NOW it makes sense to spend $100-150 every other year in an effort to reduce the risk of having to spend $2,000 or more.
You've heard me say, if it isn't in your manual, then don't do it. This may be an exception to my rule. Having your brake fluid changed every other year is a good idea that 95% of all well educated techs will agree with.
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| Q: | FAQ 57: Coolant Questions | | A: | While coolant and antifreeze may have some differences in chemical composition, I use the terms interchangeably for the purpose of making this simple to understand.
Green coolant is the normal coolant or antifreeze most of us are used to. We mix it 50/50 with water to raise the boiling point of water from 212F to 240F or so.
Red coolant is normally the same as green coolant except found in foreign and European cars.
Orange coolant is the long life coolant found in many newer domestic cars and trucks. It is not supposed to be changed for 50 to 75k or 5 years or so.
We process about 10k cars a year and we are seeing a couple of things with the orange long life coolant that makes us very uncomfortable. We are seeing a brown thick milky substance floating on top of the coolant in the overflow jugs and we are seeing an orange like gel (looks like jello) just under the radiator cap and in the neck of some radiators on some cars with long life orange coolant. We are also seeing much more corrosion on newer model cars but we are unsure if it is related to the orange long life coolant or not.
Last, most folks are very uncomfortable leaving the same coolant in their car for 100k. Really, there is no way a car will end up with the same coolant for 100k because we will have to do some cooling system repair (water pump, hoses, radiator) in that first 100k and very few of us will contain and reuse coolant we drained from a customer's car.
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