Hi folks

Any ideas on the following problem? I have a low milage 2003 crossfire that has developed very bad engine noise. I can only describe it as a knocking noise which is much more noticable when the car is moving extremely slowly or stopped (eg at traffic lights). The noise doesnt seem to be affected by the engine being warm or cold. If anything it appears more noticable after driving for half an hour say, and then slowing and stopping (at junctions or lights).

Ive had the oil changed and a new oil filter inserted to no avail by a local non-specialist mechanic. He did mention a possible problem with one of the pistons being out of sync. but someone else has told me that that in this car that is impossible as all the pistons are linked together? Im totally ignorant of the workings of the car and am looking for a few ideas from anyone who is more knowledgable than me as to what the problem might be.

Any ideas would be very very helpful. Thanks in advance.

Dominic

 

Yes, the pistons are all linked together by the crankshaft. You mentioned that you changed the oil. Is this the first time you changed the oil in 25,000 miles? What is the oil change history of the car?

 

"non-specialist mechanic" they scare me

 

The car had a perfect service history when i bought it (at 20000 miles)...ive topped up the oil twice and had the oil changed on two occasions between then and now (once at its MOT and a few weeks back when the mechanic was having a look to see if he could identify the problem).

Just a bit more detail about the problem...when the car is in neutral gear and im stationary the noise is quite apparent. If i leave the car in neutral and rev the engine (even slightly) the noise dissapears almost instantly.

 

Sounds like rod knock. If a bearing in the engine fails, you can get that kind of noise. Whatever it is, it's not going to get better by itself. Actually, it will only get worse. A "specialist" mechanic will probably want to listen to the noise using a mechanic's stethoscope, and may be able to pinpoint it much better than any guessing that could be done long distance over the internet. Depending on the diagnosis, it may be necessary to pull and rebuild the engine. I don't know if Chrysler extended a 7-year, 70,000 mile warranty to that car or whether it would be transferable to a second owner, but you should check to see because this is going to be an expensive repair if it's a failed engine bearing.

 

been doing a bit of internet searching on this rod knock (im praying it isnt that)...a few people have mentioned that the noise associated with rod knock gets worse or more noticable at 2.5-3k revs. Mines doesnt seem to do this...the more revs i apply the less i seem to notice the sound.

I went out and started the car cold this morning. No noise at all. After 4-5 minutes including a bit of engine revving in neutral to warm the engine the noise appearred (does this rule out piston slap???...i believe piston slap gets better as the engine warms?)...just a constant ticking/knocking/tapping. Ive also read that rod knock is more noticable from the bottom of the engine but without a stethescope it was impossible for me to tell where exactly it was coming from EXCEPT that it was definitely in the vicinity of the engine.

The pattern in neutral is this...vroooom (rev the engine and the noise is less noticable)...as the revs fall a second or two after taking my foot off the gas then the noise appears...knock,knock.knock...vroom (rev again and the noise lessens). I HATE to say it but from what ive read i think it is rod knock (the only thing that doesnt tie in with this diagnosis is that the knocking sound does NOT get worse as i approach 2.5-3k revs???)

As mentioned i think it is impossible to get an accurate definite diagnosis over the net. One more question though...ive phoned a Mercedes dealer (Mercedes engine i believe) in the area and asked if they could look at the problem for me...they said they dont have any Chrysler software? and couldnt do it.

Am i best going to a chrysler garage? rather than waste more more on "non-specialist" mechanics??? Basically what im asking is "Could most reputable mechanics diagnose this OR do i need a chrysler mechanic?"

Once again thanks for ANY reply

Dom

 

I don't think software has anything to do with it. This is a mechanical problem, not a computer-related problem. Frankly, I wouldn't go to a dealership with a problem like this unless it was under warranty. Very few dealership mechanics have ever rebuilt an engine. The usual approach in a dealership dealing with a warranty problem is "R & R", remove and replace. It's more cost effective for them to replace the engine than re-build it. Ask around town for somebody who rebuilds engines, especially German engines.
If you want to invest in a mechanic's stethoscope, hunt one down on the web. You should be able to find one for less than ten bucks.
Good luck to you on this.

 

Did you ever find out what it was?

 

...or does anyone else have any more insight?