Jim Grant's Tech Tips
'96 Plymouth Caravan, Interference Engine?
Q: I had the head gasket replaced on my 96 Plymouth Caravan with a 2.4-liter engine. One day after getting it back, it started to stall when stopping every time. I brought it back to the shop that did the repairs, after his inspection, he told me my PCM is shot. I then brought the van to another garage to have it diagnosed by someone else. The second diagnosis was the cam timing is way off. I want to know if my motor is interference or not?
A: Well I can pretty much guess why youre asking whether or not you have an interference engine. You want you know if the valves have been damaged by the guy who replaced the head gasket because he didnt set the valve timing correctly or should we say way off. First, your engine is not shown to be an interference engine, so it is unlikely that the valves are damaged. If the valves were damaged, the engine would be running very poorly and the check engine light would likely be flashing in a panic mode. I do have a bit of a problem with the vehicles computer being bad (PCM), it is unlikely. It is possible that the valve timing is off. If valve timing is off the engine will perform poorly overall, not just at idle but at road speed as well, it will be lacking power and the get up and go that the engine should have. Id tend to lean toward the valve timing being off. So how do you get his problem solved? You can ask the first shop to double check the valve timing. If they are not agreeable, have the other shop correct the valve timing. If this corrects the problem, then present the bill to the first shop. Word of warning, if the second shop is wrong in their diagnosis and the repair doesnt correct the problem dont bring that bill to the first shop.