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I have a 2002 Chrysler town and country Limited 3.8L van. My engine has a slight knock?
it recently started as one day last week I felt it idling harder than normal. I do maintenance and regular oil changes. It runs fine other wise but has a knock you can her when in front of the van. What could this mean do I need another engine or could it be the pistons or what?? Help so I know what I am up against in the near future and how much should I pay for another engine? Thanks...
4 Answers
- krazybob613Lv 78 years agoFavorite Answer
Piston Slap is fairly common on high mileage engines, generally heard at idle when the engine is cold it may also be detectable at warm idle. Piston slap does not get louder when the engine is revved up it actually goes away at higher rpm's. Engines may consume more oil but do not fail catastrophically from piston slap.
Rod Knock is far more serious, usually loudest when the engine is fully warmed up rod knock gets louder and sharper when the engine is revved up. Rod knock must be dealt with immediately by replacing the engine bearings to prevent a sudden, complete and catastrophic engine failure.
A practiced ear can quickly distinguish between the sound of rod knock and piston slap so take it to a mechanic and ask them to listen to your engine.
Using a heavier grade of oil will generally minimize slap but nothing short of new bearings will prevent rod knock from rapidly deteriorating into a broken engine.
Source(s): 40 years behind the wrench and wheel. - Richard ALv 68 years ago
Try putting in 20W-50 oil and see if that quiets it down. From reading the reviews, the engine is not a real problem with this model. Heavier oil will keep it going for a while longer, perhaps years, but if it gets worse, you may need some major work done if it's a bad bearing. By that time, the value of the vehicle will be scrap metal. I wouldn't invest a lot of money in it right now unless you can find a low mileage used engine cheap.
Always get a second opinion from a good mechanic who can see it live, and listen to it in real time. It may just be nothing at all... maybe.
- 7 years ago
It may not be your motor at all. Check your torque converter bolts. If you only get a random knock at idle or on the brake with a light throttle (power brake) then it may be just tightening the 4 bolts that mount the convertor to the flex plate. There is a cover right next to the oil pan held on by 2 10mm bolts and a large 18mm bolt that also holds on a transmission brace. remove those 3 and the plate should slide out, youll only see 1-2 18mm bolts at a time so you have to tighten them and then turn the flexplate to you can get the next one. Should take you about 30 minutes once you got it up on ramps or take it to a shop. I did mine and no more knock.