When should I change the timing belt on my car?
The philosophy "if ain't broke do not fix", doesn't work for the timing belt. If it broke, then can bend valves and put a hole in the piston. Normally the engine repair cost much more than a timing belt change. Worn timing chain/belt can cause engine to run rough, decrease the power, and fuel mileage, and even worse, the engine refuses to run at all. It is difficult to check the wear on a timing belt, because access difficulties, so plan to change the belt at recommended intervals. As a rule, most OEM recommend replacing OHC rubber timing belts at 60Kmiles, but there are exceptions. Porsche, Volvo recommends belt replacement at 50K up to 100K depending on engine models. Acura, Audi and Chrysler allow 90K between belt changes. Ford, Mercury and Toyota up to 100K, but not for all engines. Changes in belt materials have improved belt durability to 100K, where "long life" materials are used, as "highly-saturated-nitrile" (HSN).
Timing chains usually gives some warning signs before they fail (but not with belts). Noise from inside the timing chain cover indicates that it is overstretched. You can check the status of a timing chain by removing the distributor cap and turn the crank shaft pulley in one direction (VERY SLOWLY) until distributor rotor moves, mark with a chalk crank shaft pulley to engine. Now turn it in the opposite direction (VERY SLOWLY) until the distributor rotor starts to move the other way. If the crank pulley has to be turned more than half an inch to move rotor, the timing chain and sprockets, are worn up, and have to be replaced.
While changing the timing chain/belt, it is easily accessible for other jobs, such a water pump replacement, so it is a good idea to replace other belts, and the water pump. Make sure to send your car to professionals. It is not rare for people to have problems with engine after replacing the timing belt. In all my cars I do it by myself. It is not impossible, but you will spend more time than a professional. If you decide to do it by yourself, then get the Haynes Repair Manual (Based on a complete tear down and rebuilt), specific for your car. Go to the part Engine, and use the chapter Timing belt removal inspection, and Top Dead Center (TDC) location, and put the number one piston at TDC on the compression stroke. This can be found by putting the thumb over the spark plug hole and the pressure will push your finger upward till piston reaches the upper point. This can be done by inserting a long blunt object into the spark plug hole. Note the point where the object stops moving out this is the TDC.
YOU MUST ALIGN TIMING MARKS BEFORE REMOVING TIMING BELT.
on Oct 20, 2010 | Chrysler Sebring Cars & Trucks