slight judder?

[hoover]

Hi all,
Not sure about this, pulling away on low revs while releasing the clutch I get a bit of a shake/judder, doing this with a few more revs and it's ok. New clutch fitted 2 years ago(main dealer)
Could it be air in slave cylinder or engine mounts, or more? Opinions gratefully received, thanks.

[Eldorado]

how low revs?
has it always done it? any chance you're not shifting at a high enough rpm?

[hoover]

Well it's when I pull away from standstill, so the revs are pretty low, when shifting gears on the move the problem doesn't exist, if I rev to about 2000 when moving off it's ok then.

[Razorback1980]

Do you have or have you had any leaks on the back of the engine that might get on the clutch? Maybe a coolant leak from the water valve or an oil leak from the back of the cam tower? It sounds like the clutch is grabbing slightly.

[hoover]

Will have to check for leaks, but not aware of any, wondered if the flywheel was dirty when the clutch was fitted, but hoping for something less of a pain. thanx.

[Brando]

Mine does this too.

Just recently put in a clutch, new rear main, etc.

Just leave the line with RPMs around 1500 to 2000 and it's alot better, believe me.

[hoover]

Yes you're right, just felt you shouldn't have to!

[Razorback1980]

You are right, you shouldn't have to. I've never personally worked on a car with this problem, but I know in braking systems, grease and other foreign substances generally cause brake systems to grab. I know there are differences between the systems but there are similarities as well....so what I offered was more of a guess than a "I've seen this before" thing. Anyway, I hope you find the problem.

[Brando]

I believe wilk's chip fixes this. I think it's a commonality of the NA shudder on later cars.

[Eldorado]

the shudder that is corrected by wilk's chip is the 'drop and shudder' that you get when you're reved up and you take your foot off the gas and it dips below 900..

not a shudder on acceleration.

[Brando]

Wierd but I only notice it happen when I don't use the gas pedal from a standstill, or the RPMs are below 1200.

[hoover]

Thanks Tom and everyone, will keep an open mind on this one, it's not unbearable but would like to sort it as it spoils an otherwise nice ride.

[CJFusco]

My old 944 did this for a little while after I had the clutch replaced. After awhile the judder just went away.

[Slam]

Mine does this on hot days when I've been city driving. Engine heats up, oil leaks out rear main seal and clutch chatters. I'm not fixing it till the clutch is well and truly dead. Just rev higher in the meantime. Kyle's right - this is a different judder than the one the Wilk chip fixes (which can also be fixed with a throttle-stop tweak).

[hoover]

I like things that just go away CJ, Maybe I'll be as lucky!! At 7000miles on, I have my doubts though.

[CJFusco]

at 7K, I would have my doubts too

[Eldorado]

couldn't be his balance belt off a tooth or two, could it?

[Techno Duck]

My car used to do this often, attributed to a leaking RMS. Only happens if i run the car hard, usually on the way home from an autocross only. Hardly ever get the problem on the street. I switched a 20w50 weight oil, the Castrol GTX high mileage type. RMS seal leak has stopped (no more leak coming off the rear of the pan) and the slip has stopped. Worth a shot.

[VaSteve]

My car seems to do this a bit as well. Did it with the old engine, does it with the new engine. Same clutch and PP, but I cleaned it all real good before reinstallation. RMS is new. Seems more prevalent when the car is cold. The rest of the time, it's on the track.

[Razorback1980]

If you get a substance on a clutch plate, you can't get it out. They are porous and it soaks in....so to speak. Flywheel can also be a contributor to this.