Squeaking from engine

[apanossi]

I'm new to this forum, but have had my 2002 Carrera 2 Cab for 6 years now. I have been searching the 996 forum on this site at length about various squeaking noises coming from the engine, but I have not found anything conclusive as to the origin of the noise that I'm hearing. So, I apologize if this post seems redundant to some of you.

I began noticing a squeaking noise coming from the engine about one month ago. The noise seems to occur at idle or while coasting to a stop in gear. Also, if I'm in neutral and stepping on the gas, the noise will increase with the throttle. It goes away when the clutch is depressed or when I'm accelerating. The noise will be there regardless of whether or not the engine has warmed up. It seems to come from the engine and not the bell housing. It doesn't seem to affect the car's performance but I would like to know what it is and if I can get rid of it. My car has almost 30K miles on it and has had some RMS/IMS problems in the past. These issues were resolved long ago (knock on wood).

Any help would be appreciated.

[RFM]

In spite of what you mention that the noise is coming from the engine, i think the clutch is the culprit, the release bearing in the furst place.

[apanossi]

I think you're right about that, given previous posts on this topic. Is there anything wrong with leaving this noise alone or should it be addressed? I guess that would be the real question. Thanks for the input.

[RFM]

The best you can do, in my opinion, is go to a dealer or an independent to pinpoint the problem. The noise will not disappears at his own, it can only be worse.

[1999Porsche911]

Typically, a bad throwout bearing will only make noise when the clutch is disengaged (pedal depressed). Since your noise goes away when you drepress the clutch pedal, it is highky unlikely it is the throwout bearing. My first goal would be to determine for sure whether the noise is from the engine or bellhousing. If engine, it could be a bad belt, pulley or power steering pump. If the bellhousing, and it makes noise when in neutral and clutch engaged and disappears as you depress the clutch pedal, it may be a bad gear bearing.

Edited March 14, 2008 by 1999Porsche911

[apanossi]

I'm not completely sure if the noise is coming from the bellhousing. When I open the engine lid, it sounds like it's coming from somewhere deep within the car (possibly the bellhousing). The sound is very much like a bad belt but it does not appear to be coming from the belts that are visible when the engine lid is open. Someone once mentioned something about faulty hydraulic lifters being the source of a noise that sounds similar to the squeaking that I'm referring to. I'm not terribly tech savvy, but what are the "lifters" and how important is it to get these replaced? Thanks for all the troubleshooting thus far.

[apanossi]

It turns out that the squeaking sound was from the bellhousing. There was a rattling noise that started to become more and more noticeable when idling, which went away along with any squeaking when the clutch was depressed. The dealer ended up doing the fix. The cause was a bad dual mass flywheel. The cost........$3300!!!! :o I changed out the RMS while in there. My car is an MY02 996 Carrera 2 with 31,000 miles. Other than not having driven it for about a year while I was abroad, the car has mainly seen action on the weekends. It's only when I made it my daily driver last year that troubles began.

Edited April 14, 2008 by apanossi