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  • zaken1 07/25/10 1:36 am PST

    I think it is far more likely that the timing belt has broken or jumped out of synch than that a sensor is defective. There are three different motors used in the 1998 Stratus (Two I-4s and a V-6). None of them have crankshaft position sensors. Both of the I-4 engines have a camshaft position sensor; but the V-6 has no camshaft position sensor. On the V-6, it is easy to check to see if the timing belt has broken or jumped. Just take the distributor cap off and crank the starter while someone watches the distributor rotor. If the rotor spins steadily when the starter runs; then the timing belt is not broken. To check whether the V-6 timing belt has jumped out of position; locate the timing marks on the crankshaft pulley, and turn the engine until the marks line up somewhere between TDC and 10 degrees BTDC. Then look at the position of the rotor tip. It should point either directly to the cap terminal that connects to the # 1 spark plug wire; or should point to the terminal that is directly opposite the # 1 wire terminal, on the other side of the cap. If the rotor tip points anywhere else but to either of those terminals; the timing belt has jumped out of position; and must be replaced.

    The 4 cylinder motors do not have a distributor, so they cannot be checked by the above method. But they can be checked to see whether the timing belt has broken by several different methods. If you can see the camshaft by removing the oil filler cap and looking through the opening; just watch the camshaft while someone cranks the starter. If you can see the camshaft spin when the starter runs; then the timing belt is not broken (but it still could have slipped out of position). If you cannot see the camshaft through the oil filler opening, or you can see the cam turn but want to know whether the belt has slipped; then run a cylinder compression test on the engine. If the compression is within manufacturer's specifications (usually at least 150psi) then the timing belt has neither broken nor slipped out of position. If the compression is drastically different between cylinders; then the timing belt has probably broken. If the compression is very low in all the cylinders; then the timing belt has slipped, but is not broken and is still turning the camshaft. Either of these situations requires the timing belt to be replaced.

    If the camshaft position sensor on one of the 4 cylinder engines has failed; it will shut off the trigger pulse to the fuel injectors. This can be confirmed by connecting an inexpensive "Noid light" to the wiring for an injector, and cranking the starter. The light should flash steadily while the starter runs. If the light does not flash steadily; the camshaft position sensor is probably defective. Another way to check the camshaft position sensor is to disconnect the large air intake hose from the throttle body, hold the throttle partly open by hand or by having someone step on the accelerator, and spray starting fluid into the throttle body for 2 or 3 full seconds. Then release the accelerator, quickly slip the air intake hose back onto position, and try to start the motor. If the motor starts briefly, and then stops; the camshaft position sensor is probably defective.

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