3.8 engine idling rough-vibrating

[mjacob]

We have got a '97 GP with 182,000 miles that has started to cause some problems of late. The most recent one being a rough idle. You start the car and it sort of spits and sputters a little. When you put it in gear it almost dies, but never does. Upon acceleration it continues to run rough and sends a vibration through the whole car. It does seem to accelerate well still-just vibrates while doing so. If you pop it into neutral while at a stop sign and rev the motor it is more responsive, but when you drop it back into gear, it runs rough and almost sounds like it wants to die.

Im thinking plugs and wires, but thought maybe someone here had similar situations and what they did to fix it.

Thanks

[dmahlikGT]

Check engine light on? any codes? Could be just a needed tune up and bad mounts.

[FordMan77]

I would say plugs/wires, replace the fuel and air filter, clean the MAF and check for vacuum leaks then see what you get.

Just stick w/ stock plugs and wires. No need to get super duper quintillion platinum plugs. I personally run NGK V-Power TR55's and have yet to have and issue. Also stock Delco wires from the dealer.

[mjacob]

No che engine light is on. Still expoloring my options. Discovered earlier today a hissing noise coming from the dipstick. It is almost like a vacuum is screwed up and drawing air through the dipstick. I took the oil cap off while running and it was like a big sigh of releif came from the motor grasping for air. It is pulling air in through the oil cap when removed. I drove with the cap off for a while but it did not change anything. The engine is still rough running and vibrates upon acceleration. Still stumped and looking for options.

Thanks

[BillBoost37]

Change the pcv valve. ensure you get the o-ring back on the new one.

[fremmy182]

yeah i kind of have the same problem with the vibrating when a stop light and upon acceleration. I still havent fixed the problem but i just ordered shorter dog bones and going to replace lower motor mount and trans. mount and see what that leads to.