07 VRS - Opinions on Judder (not EGR related).

[spiderbarks]

Gentlemen of knowledge,

 

Got a few symptoms that I think may be the DMF on its way out. Your opinions if you will.

 

1) When accelerating gently from ~1400 - 1700 rpm can feel a judder like going over loads of very very small speedbumps. Happens at all speeds, but most noticable in 2nd/3rd gear through town.

 

2) Slight chatter from the engine when idling, becomes less noticeable when the clutch is pushed in.

 

3) Occasionally when stationary (clutch in or out), normally after some spirited driving there is significant engine shake. This is lessened if I turn the A/C on, and the engine revs rise slightly.

 

Everything else seems fine. Car still pulls superbly in all gears, cruises beautifully above 2k revs - just seems to be that on/off throttle at low revs in traffic situation that it feels unpleasant. Not unbearable, but definitely not quite 100%.

 

My assumption was DMF... 

 

If that is the case, are they normally swapped while leaving the clutch in situ (I assume they live pretty close to each other - I'm no mechanic)... or is it prudent to swap both the clutch and flywheel at the same time?

 

Thanks for any replies. Would just take it to my trusted indie, but I'm not even sure it's bad enough to replace yet.

[mattbvRS]

How many miles has it done, when was the fuel filter last changed and when was it last serviced?

 

1) This will likely be EGR related, it will likely want cleaning out and there is also a 'fix' for this using a different gasket which can be got from the dealers. There should be more information on here in the threads if you do a google search for 'BLT EGR gasket'.

 

2) It could be slight DMF noise but it's nothing to worry about unless it's very noisy, something to keep an eye on for it getting worse/louder. It could also be the release bearing but again it's not a big issue unless it's very noisy. I wouldn't be in any hurry to fork out for a clutch/flywheel change unless it's sounding like it's on it's last legs because both the clutch and dual mass flywheel will need replacing at the same time, gear box off, and it's easily a £400-£600 job in a garage. 

 

3) Engine shake could be the timing being out, this can be checked on VCDS and/or a failed engine mount. 

 

You could try running some of this through the fuel system to see if it lessens/cures the judder, it will also help clean out the fuel system and the injectors and keep things tip top. 

Edited 17 October, 2015 by mattbvRS

[spiderbarks]

Thanks for the reply buddy.

 

89,000 miles - Was last serviced and fuel filter changed 3800 miles ago. Full service history up to this point.

 

I've already replaced the EGR gasket with the 9mm (drilled out to 11.5mm) which cured the what-felt-like-misfire during light throttle.

 

It does seem to only be very minor at this point, so you're probably right to just suck it and see for a while. Just don't want to be left stranded if it finally decides to let go one day. £400-600 doesn't seem all that bad for the job lot - that's cool.

 

The engine shake is only every now and again which is what's odd. From cold it's fine, and if I've been driving Miss Daisy it's fine. But get back into town, and stop/start traffic after coming off the motorway seems to be when it's worse. On it's own it's not even a real issue - just thought it might be related.

[Lofty]

My moneys on Dual Mass starting to show signs of wear.

 

Can you provoke the judder by accelerating hard in too high a gear at too low an rpm?

 

Ie 30mph in fifth? If you can its 100% your problem.

[spiderbarks]

Lofty - yes. Significantly wrong gear, and the judder is very noticeable.

 

Guess I'll be sticking one trip to the garage in the budget for December time

 

Thanks for the input.