klr10

Hi everyone! Have a horrible graunching noise coming from the trans on my 964 C4. Have owned the car for a year with no major problems (had a bad DME relay and a sticky ISV - both easy fixes).
Drove the car up to a friend's repair shop for the annual MOT (emissions and safety test). Drove fine, no problems at all (about 100 miles).
Sailed through the test with no problems at all. Didn't use a rolling road, the only intervention with the trans was to jack up the front, then rear axles and just rotate wheels by hand to examine the bearings, wishbones and brakes, etc.
Started driving home, got about a mile down the road and suddenly felt a shuddering through the gear shift and a horrible graunching noise, like a spline slipping or a really worn bearing, the car seemed to jump. I initially thought I had run over a large cardboard box or something, but the car seemed fine and I asked my buddy (in the passenger seat) and he said maybe it was a plastic cover loose or something. Carried on, listening carefully and about 500 yards further it did the same again but this time for nearly a second! Pulled over and both got out to look under the car. Couldn't see anything obvious, had no warning lights up.... rang my friend back at the garage and decided to drive the mile back very gently.
Made it back to the garage with no further problems.
My mechanic friend drove it very slowly around the repair shop car park. The car jumped and clonked twice.
Decided to go home on the train.... my mechanic friend is looking at it on Monday. Any thoughts anyone? Could something have got stuck (like a CV) when the car was jacked up? The sound is quite loud, certainly can't be driven.

klr10

Oh sorry, nice to meet you all. I live in the slums of East London, England. Soon to be the 2012 Olympic Park!
Is there a way of putting images of the car from my desktop into a post?

Andy Roe

A loose drive shaft perhaps? Maybe the dual mass flywheel has failed.

Which garage do you use?

demonfish

MOT you say... C4...

how did he do the brake test?

C4 guys will know, does this bugger up the transmission if done on a two wheel roller? I know my old integrale didn't like it but could cope with it for a while...

klr10

Hi Andy, thanks for your reply. I had a new clutch and full service done at Porsche a year ago when I bought it. Done about 3,000 miles so was going to have the annual one done soon. Was thinking of using the guys at Kings Langley, anyone got recommendations not too far from East London? I have a everyday car so it can be left if necessary

klr10

Nope! used a road test and a hand held ferodo decelerometer.... wish it were explainable!

Andy Roe

I used to live in Blackheath and have used Joe at HP Motosports who is based near Fairlop tube station on the Central Line, so not far. He's is very good and very reasonalable too. His number is 07811 194540.

When you had the clutch done, did they replace the flywheel too? When it fails is can produce lots of bad noises which could very well be what you descibe.

Good luck!

Also, before I moved to Paris last May, I gave Joe a DMF that I he took out of my car when he fitted an RS clutch kit and LWF. He may still have it and if he does, you're welcome to it. Just tell him I sent you!

Andy

klr10

Thanks bud I'll give him a call on Monday and let you know how I get on..

klr10

Andy - I will also try and find out about whether the flywheel was done. The phenomenon only seems to occur when the engine is driving the wheels though (not when coasting) which makes me suspect something within the drivetrain, although I respect something like a flywheel failure could manifest itself randomly like this... I hate random faults

klr10

Any more ideas anyone?

Rocket Rob

Sorry to hear of your troubles. From your description, I don't think its your flywheel. When mine failed, it made a clunk noise whenever I accelerated or slowed but steady state it was normal. I would inspect your CV axles and motor mounts. I'm assuming you have already drained the tranny fluid already to check for any metallic flakes of both the main tranny and the front differential.

Good luck on the repair.

Uber 911

Demonfish, you were an Integrale owner? me too, which one did you have?

chris

Wachuko

+1

Check CVJs, Motor mounts, uncover clutch inspection hole and look, drain transmission oil to check for metal debris... make sure you can get the filling plug out first! before you drain the oil... (don't ask me why I suggest this...).

Best of luck, and keep us posted on what you find.

demonfish

Which one of the 4? hehe

1 Swiss 8v (16v Body)
1 Red 16v (Mint)
1 Black 16v (Track)
1 Evo 1

Ran the big ends, needed new engine, 5k later from Tanc and i could never drive it with anger again...

Uber 911

Spooky! I had...
Swiss 8v (16v body)
Evo 1
Evo II

All three bullet proof. The Evo II was amazingly reliable better than the Porsche