I've received the following suggestions for the origin of the sound:

- If it's rod knock then check the oil filter for metal bits. Result: negative

- It maybe a vac leak. Result: negative

- Maybe a stuck lifter. Result: pending

 

that what mine sounded like.. bent rods 5 and 6... remember 1.1 bar is almost double the stock boost pressure
tim

 

Zip;
Have you depressed the clutch to see if the noise changes? Does the noise diminish when the engine warms up? Try a compression test to see if one cylinder is significantly lower (possible bent rod). I'm trying to figure out a similar noise on my 01. Good luck

 

Yeh, I depressed the clutch numerous times to rule out it wasn't something rattling in the bell housing area. The sound actually progressed louder as the car warmed up and when the cold start air pump stopped it's initial startup phase. So it's either a valvetrain or rod issue at this point. Compression check would be great but to access it on these cars is pretty much disassembling the majority of the parts needed to pull the engine out for inspection. Still stumped on why it would be a rod failure, if it is a rod failture, when boost never went above 1.15 bar, AF lambda was never above 0.82-0.83, and using premium 91 octane fuel. I actually lowered the set gain on the greddy 2 or 3 pts on the initial 1st and 2nd gear pull, since the motor pulled so hard on 30 deg F ambient temperature weather.

 

Park Place Porsche had one, on initial diag sounded like a rod knock. After disassemble they found a cracked fly wheel.

 

I've certainly seen a broken tappet make a similar noise on an 01TT last year but it's not very common. That was on a stock car and not anything that was modified.

 

Hey man I feel your pain.. Remember your running almost double the factory boost pressure and the cold weather the air is much denser .. And 91 well I wouldn't run it in cold weather not above .8 bar

 

ugh that damn 91 ... and i thought the 93 we have up here is bad.

 

sharkster,

You can pin point the noise if it is a tappet. If it is a bent rod rubbing the crank you will not be able to pinpoint the noise.

Send your oil out and have it analyzed. Looking at it will not tell you a thing.

 

I am interested to see the result of this finding and I hope your engine is ok bro.

 

"The same gas I've always used...Chevron 91 octane"

^^ DOH! ^^

Unfortunately, this gas is not adequate for ANYTHING above stock boost pressures...
+ cold weather == very hard on the motor

 

A fellow 6Speeder, adeoosis, just sent me a video that sounds exactly like the issue I observed.

http://www.youtube.com/watch?v=qQ8mNVI9_G8

It sounds dead-on exactly the sound coming from my engine. The motor ran fine after the short gear and highway runs since the amount of pull never changed...it's when I was at my driveway that I heard that ticking sound getting louder and louder. Does anyone know the amount of labor to check for an intermediate shaft failure?

 

Is there any oil leaking? Usually the engine stalls and oil starts to leak out.

I have heard of this on regular 996s. I believe its a rare but known problem. I think you can rebuild engine but most replaced under warranty.

I dont know how much $ to check for this problem.

 

After the recent engine failure I experienced... my heart goes out to you Brother!!!

 

Bad lifter/broken spring, intermidiate shaft? no, doesn't sound like it, that's usually an issue with 996n/a engines.,cheers.