Engine grating/rattling at 3000rpm

[stead09]

Hi everyone,

This is my first post so here goes.

I get a loud grating/rattling noise has the engine accelerates through 3000rpm. I took the car to the Porsche dealer and they replaced all the lifters on the r/h side, I got the car back and one day later the noise as appeared again the dealer told me to run in the new lifters for a couple of days to see if the noise goes away.

Can anybody advise me on this defect please im just worried the car could be getting damaged.

[RF5BPilot]

Others can give you better advice, but Raby talks about rattling as a symptom of intermediate shaft failure.

http://www.autofarm.co.uk/engines/water_cooled/press

There are probably other, more likely and less expensive explanations for this sound.

[dmelchar]

Hi everyone,

This is my first post so here goes.

I get a loud grating/rattling noise has the engine accelerates through 3000rpm. I took the car to the Porsche dealer and they replaced all the lifters on the r/h side, I got the car back and one day later the noise as appeared again the dealer told me to run in the new lifters for a couple of days to see if the noise goes away.

Can anybody advise me on this defect please im just worried the car could be getting damaged.

I have had a similar problem with my '02 C2. I first noticed the noise two years ago when I bought the car with 11,000 miles on it. I thought it was a loose exhaust tip. The noise occurs around 3,000 rpm when at partial throttle. I have had Porsches for over 30 years, with their little problems, but this was my first 996. I took it to my local dealer while it was still under warranty and the tech at first thought it was the exhaust as well. But, after a few return trips he realized that it was something else. Last winter the dealer was able to get PCNA to authorize partial disassembly to try to identify the problem. After five weeks the tech could find no visible problem. He replaced the tensioners, oil pumps, all the lifters and when the engine was reassembled the noise was still there. The noise does seem to occur at the transition point for the variable cam. In spite of the noise, the engine seems to run strong, and otherwise normal. The dealer service manager has indicated that he plans to request PCNA to replace the engine since all reasonable efforts have been made to resolve the noise, without success. The service manager wanted to wait until the fall when business slowed down to pursue the replacement. I think the problem has to do with the variable cam and it is somehow internal to the engine! I have read a few other owners who described similar symptoms, but no one seems to have resolved it, so far.

[stead09]

Thanks for the info DMELCHAR ,the sound seems to be going away so it could have been the lifters............ Then again it returns randomly so I will give it a couple of weeks and see what happens. If no joy I will return to the OPC and pursue it further.

[stead09]

Thanks RF5BPILOT, I found the article to be an interesting read , unfortunately through my own fault I forgot to mention my car is a MY03 C4.The article refers to the early 996 models. Thanks again for your reply.

[stead09]

Thanks for the replys,

The noise has disappeared just as the porsche tech said it would,it took 2 weeks to settle down, but hats off to them they did a really good job.

I am also thankfull that porsche provide a great warranty and customer service is just as good.

Just thought I would pass on some good praise.