Rep Power: 0

Hey guys, I don't know if this is there right thread but here my problem.

My dad has a 1996 Plymouth voyager and has 180,000 Km. The trouble is that whenever the car comes to a complete stop at signal and stop sign, it sort of jerks for some reason, you have feel it jerk the whole jerk. We found out that its coming from the under carriage. It also occurs when he starts the van and wait for it to warm up.

I was thimk that it could be the Catalytic converter, but I'm not sure.

If you can tell what the problem is and the seriousness it would be appreciated.

 
Rep Power: 10

when was the last time it had a tune-up/ fuel filter change?

 
Rep Power: 0

I believe it was about 2 months ago. I not really sure.

 
Rep Power: 746

you need to elaborate on what "jerk" is. Are you talking about the engine hesitating or is it more of a suspension type thing? Can you determine if its coming from one side of the car or the other?
be more specific.

 
Rep Power: 0

I did some test over the weekend and found out that the jerking motion only occurs when the heater is on. There isn't any noise coming from the engine. The jerking is up-down movement rather than right-left. Its felt throughout the whole van.

 
Rep Power: 735

Does it happen at certain speed ( i.e. like when it's downshifting ) or this jerkin feeling.. is it like a misfire or not firing.. or tranny jerk.. does it hesitate at all?

 
Rep Power: 746

Alright i am not understanding what you mean by jerk. What is jerking? the motor? or the transmission?

when trying to diagnose noises/movements or whatever it may be it is hard to understand unless actually felt yourself. Now you are trying to describe it through your post, but you need to be as specific as possible otherwise you will get random answers thrown at you and probably won't find the problem.

 
Rep Power: 715

Well there is not much info to go on.. so I'm just going to trow some ideas at you.

1) get some fuel injector cleaner.

2) check your tranny fluid, may be low, or old, perhaps even replace it, you torque converter may be malfunctioning, you may have to replace it.

3) Stop tapping the brakes!

4) Very low current, fan-on causes car to hesitate, get your alternator tested.

5) Shocks are gone, so you are bouncing when stoped