997 Turbo Engine Rattle

My 2007 Turbo has roughly 15k miles and after warming up to operating temperature (not cold) produces a rattle that seems to be coming from the engine area. It sounds like a chain rattling. The rattle is only noticable between 1500 and 2000 RPM and under very little load. When I accelerate quickly, the rattle is not present. My dealer believes this is a normal sound. Has anyone experienced that same? And, if so, what steps were taken to resolve the issue? Turning up the stereo volume to mask the sound is not an option I am willing to live with.

I heard that GT3s have that, coming from the light wheight flywheel, but cannot confirm that from my own experience.

I'm willing to bet it is something in the driveline which would sound like the engine area because well the driveline is between you and the engine in a 911 . If you had a lightweight flywheel I would suspect that, but you don't, so I would expect that when your transmission fluid gets warmed up (and thinned out a bit) that something in the driveline has a bit of lash that is noticeably within that RPM range and as you either increase load (and cause parts to mesh tighter together) the sound goes away. A timing chain with a bit of flex in it could cause the same problem. Most Porsche dealers are equipped with a set of remote microphones that they can attach to various places on your car, drive your car, and attempt to pinpoint exactly where the sound is coming from. Has your dealership offered to do that? If not, you might want to consider another dealership's service department to see if you can get them to at least diagnose the probable cause of the rattle. Once that is known, then someone can tell you whether or not it is likely to be serious. I've heard rattles from Porsche engines that are nothing serious, and I've heard rattles that a few miles later became an intermediate shaft failure and a blown engine. If your car is under warranty it should be no problem for a good dealership's service department to take the time to diagnose what is causing that sound or at least what the most likely culprit is. I'm not aware of any recall or regular problem with these engines that matches what you are describing. I hope that helps!

Just a clarification... GT3s have a dual mass flywheel. They should not rattle. GT3RSs have a single mass flywheel...hence the noise.

thanks, as I said do not know from experience, just heard that some of the GT3 variations rattle.

Before I had my Cayman S , I had a 996 turbo for 4 years... the motors in the 996 and 997 turbos are essentially the same, with the 997s producing more HP and TQ through the use of different turbos, different software and a little more boost... anyway, it's not a serious drive-train problem... what you're hearing the the bearings going out on one of the idler pulleys that the belt goes over... I had to have two of them replaced under warranty during the four years - have the dealer check these. brad

Thanks, Brad! The plan as of now is to get my dealer committed to researching the issue.

when I took it in with the noise - I was taking it in for an oil change anyway and mentioned the noise - the service writer actually knew what it was right away... under load, it doesn't make much noise, but not under load, it rattles away - kind of sounds like when the bearings go out on a water pump on a Chevy ... it's definitely not a "normal" sound. brad

Brad, my service appointment is scheduled for this Monday morning. I will post the findings and outcome. I am beyond ready for the return of a normal sounding 997 Turbo engine.

I have a 2009 C4S and I'm experiencing something similar. I took it to the dealer and there was a Porsche issue regarding a rattle while slowly accelerating. However, it is still happening. It doesn't happen when quickly accellerating. I have an appointment to have it looked at again on Wednesday. Not sure it is the same as your issue but it is annoying. Would like to hear if you get it resolved also.

I am having the exact same experience, but my dealer is not committed to researching/fixing the problem. They keep saying that it is operating within normal limits and that the diagnostics are not indicating a problem. I am very frustrated and tired of hearing the rattle as a lot of my driving is at 45 mph or less. As you mentioned, the rattle is most noticeable during slow accleration and under 2k rpm. I look forward to hearing about your dealer experience and their attempt to solve the issue. I have to say, it would be a very satisfying experience if I could walk in and tell my dealer what the problem is.

I had my C4S examined by the dealer yesterday and was told that it is also operating within the normal limits but that with the PDK it is lugging because it needs to be driven more "Agressive" that's what he said! He also said that the sound is similar to what happens when a manual transmission is driven slowly in the wrong gear. He stated that I need to manually shift the PDK to a lower gear or use it in Sport mode. Just not sure what to believe at this point. Manually shifting down does stop the noise. Not sure if this is the answer though.

Sounds similar to the story my dealer is giving me...but not related to the transmission. I also drive in Manual mode (Tiptronic, not PDK ) and this helps keep the rattle to a minimum. I do this to keep the revs up to 2k or higher. I met again with my service manager this morning. Basically, he agrees that the sound is not normal, but they have been advised by Porsche not to tear into the engine. He believes the sound is related to the Intermediate Shaft (?) or a timing chain tensioner issue. They won't do anything to the engine until it breaks or there is an abundance of metal shavings in the oil.

This might be an old thread but wanted to post what I have found out. The Rattle that the Turbo makes below 1800 RPM is normal. It's the slop in the Gearing driving the Intermediate shaft. The Turbo doesn't use chains to do this like in the Carrera 997 engine. Discovered all this out from a Porsche dealer that is also a large racing organization Brumos Porsche in Jacksonville FL. Ian