porsches996

Hello folks...,

I do have now since 2010 a 996 C4 2000 with 60K on it
Now i'm looking for a 996 Turbo Porsche.

Today i went to see a 996 2002 Turbo with 60K on it.
My question is...when the car was running on neutral at idle i can here a clapping sound cumming from the engine..like a valve clapping sound.
I told it to the guy and he said that was normal.

Once i'm back home i started my Porsche and i can say that at idle there is absolutely no clapping sound at all the engine just run smooth as it is supposed to be.

I also listening at an other 996 turbo 2001 and the engine was doing about the same clapping sound...is that normal for a turbo engine or not?

Robert

rmc1148

Different engine in the Turbo= noise is normal.

jumper5836

Shouldn't be any clapping. Do a search for 996 turbo exhaust on youtube. Plenty of sound bites there. With an unmodified exhaust I you can barely even hear the engine.

rmc1148

I believe is hearing the mechanical sound our engines usually make.

p556guy

There's definitely more noise at idle with the clutch out vs in.

Tuxiemama

Under zero boost our engines sound amost like Nancy Boy 911 CS engines but the latter are muffled by the fageena sounds

Macster

My experience, based on among other things my time with my 03 Turbo, if the engine/drivetrain was fully up to temperature -- like after a thorough test ride/drive -- and if the car is equipped with a manual transmission the tranny (or clutch or both) can making what could be described as a clapping sound. It is gear (or clutch disc) rattle.

My Turbo makes this when fully up to temperature, sometimes. It has to be warm. The transmission fluid is pretty thick otherwise. I can stop the noise by just normally pressing the clutch pedal then releasing it. I can make the noise reappear by revving the engine a bit.

If the car is equipped with a Tip or the engine/transmission was cold…that could change things. Too bad you didn't make a video/audio of the noise.

Kevinmacd

Turbo engines have noise IMS shafts, you are probably hearing it. If the clutch and flywheel were changed to a lightened package rather than the stock dual mass flywheel, it will rattle.

leftlane

Rattle sound = normal on the TT. Both of mine have a rattle sound from the IMS and it is totally normal. Some sound louder than others.

Daytonaman

Oddly, I have an 05' Tip, and it rattled even with Motul 20w60; Great oil, but Rotella T6 quieted it. When I test drove it, it was cold out, and it was quiet, like a new vehicle. When we finished the usual 0-60, 1g cornering, 3rd gear wot, it sounded like and Erector Set. Almost didn't buy it. Glad I did.

602996TT

Curious has your car always done this? The reason I asked is I just got my car back after 3 months. I had my transmission rebuilt to fix 2nd gear pop-out and also replaced my clutch to the Sachs 2.5 kit with new pressure plate and throw-out bearing but kept my stock dual-mass flywheel since it was in great condition. Your post caught my eye because this exactly whats going on in my car I only hear it when car is fully warmed up at idle in neutral and as soon as I push the clutch in noise(clatter) goes away. I cant hear it with the AC on only at idle and up to 3000 rpm's is when my exhaust gets to loud no longer here it. Is this really normal I've had my car for over 5 years but since I haven't had it for over 3 months I can't remember if it normal sound or not? I was thinking I had a bad throw out bearing or maybe my clutch still needs to be broken in since I have only had about 250 miles since getting my car back. I am trying to figure out if this is just normal for are cars of if I got a bad new throw out bearing or even maybe air still in the clutch system.Does anyone else notice this when their clutch is pressed or am I just hearing something that's just normal? Thanks!

Macster

Can't recall my Turbo always making this noise. Probably not. But I can't recall when I first heard it either.

My car was a low miles car -- 10K -- when I bought it. The original transmission was replaced at IIRC around 30K miles due to a selector shaft seal leak.

As an aside, the new transmission was a much nicer transmission in the shifting department.

If I had to guess I'd say the noise appeared after the new/replacement transmission racked up some miles. BTW, I've had the fluid changed several times since and this doesn't seem to make any difference.

The first time I heard this I do recall that while at first I was a bit concerned for I instantly imagined engine problems it dawned on me what might be the cause. A depress of the clutch pedal made the noise go away and from this reaction it was clear to me what the source of the noise was.

Now that I think about it this suggests to me that it didn't always make this noise.

BTW, my 02 Boxster makes a similar noise but it is not as loud -- the 5-speed is a lighter transmission -- and the Boxster engine is a smoother idling engine than the Turbo. But the Boxster has a lot more miles on its clutch and transmission (though the fluid is changed regularly in the Boxster 5-speed, too.)

In the case of your car I believe the noise is normal, nothing to worry about. The Sachs clutch may be lighter (or heavier) than the stock clutch and as such its propensity to rattle a bit on the input shaft has been increased, or it has changed the dynamics of the input shaft and its gear sets and as such the gear box is more noisy as a result.

If the release bearing were bad I think you'd know about it by now. They generally do not linger half way between ok and failure. They also tend to be noisy when the clutch is depressed.

However, for your peace of mind, get a second opinion by letting an experienced tech give a listen. Be able to demo the noise to him.

The new clutch might have a problem. It is rare but not unknown a new component can suffer a premature problem/failure and if this is the case you want to ID this ASAP.

602996TT

I know it's driving me nuts wondering if it always made the sound or if I am over analyzing I have only put around 200 miles on the new clutch & transmission so I am going keep driving see if it clears up after 500 miles. When I first bought my car it had 11,000 miles as well maybe I am just listening to hard since I had a bunch of work done on my car in last 3 months. thanks for your input!

Macster

If you are over analyzing the noise makes no difference. It is worth having a Porsche tech give a listen. With just 200 miles on the new clutch and transmission there is some grounds to suspect the clutch or the transmission may have a problem.

I do not like your plan to drive the car another 300 miles to give things a chance to quiet down. A clutch and transmission should be free of any untoward noise from the second the car leaves the shop and remain free of any untoward noise for thousands upon thousands of miles. The transmission (if new/rebuilt) might get a bit easier to shift but this is all the change you should detect.

There is a saying about these Porsches that no noisy one ever got better before it got worse.

Worst case scenario if there is a problem and the clutch grenades and takes out the transmission or possibly the engine block you are really relying upon the rep of the shop that did the clutch/tranny work to make you whole again.

While the shop owes you a good job with good parts, you owe the shop some reasonable chance to recognize there is a problem and be able to deal with it before the thing (possibly) hand grenades.

Thus I restate my recommendation you have this listened to just in case you are getting an early warning of pending doom.

I'm not trying to be a scaremonger, I'm just being cautious.