D4204T Idle judder - running out of ideas!

[deltham]

Hi all, hoping you can help me with a problem I've been trying to fix for about 12 months.

I've got a v50 2.0d with 142,000 miles on the clock. Since about 130,000 miles the car has got a judder when idling. The symptoms include a mild judder that occurs a few times a second, accompanied by a much stronger judder that occurs every couple of seconds. However the judder is quite random - it's not rhythmic. The judder is only evident when the engine is warm, and is more pronounced if the a/c compressor is running - I.e. the engine is under load. If I raise the revs to 1400, the judder disappears.

I searched the forum and came up with a short list of potential causes. This has led me to clean the throttle body, replace the EGR, check the engine mounts and get the injectors checked by an injector specialist. I regularly use Wynns injector cleaner. Incidentally, I had the clutch and flywheel replaced at 118,000. But the judder persists.

The engine also has an acceleration flat spot at 1200rpm. But that existed before the judder materialised. Could that be related?

My local Volvo dealer and trusty local mechanic can't diagnose the problem.

If anybody has any suggestions I would be very grateful to hear them. Thanks.

[cheshired5]

I can't help specifically with yours but maybe follow the progress of this thread http://www.volvoforums.org.uk/showthread.php?t=229105

[Clan]

Originally Posted by deltham

Hi all, hoping you can help me with a problem I've been trying to fix for about 12 months.

I've got a v50 2.0d with 142,000 miles on the clock. Since about 130,000 miles the car has got a judder when idling. The symptoms include a mild judder that occurs a few times a second, accompanied by a much stronger judder that occurs every couple of seconds. However the judder is quite random - it's not rhythmic. The judder is only evident when the engine is warm, and is more pronounced if the a/c compressor is running - I.e. the engine is under load. If I raise the revs to 1400, the judder disappears.

I searched the forum and came up with a short list of potential causes. This has led me to clean the throttle body, replace the EGR, check the engine mounts and get the injectors checked by an injector specialist. I regularly use Wynns injector cleaner. Incidentally, I had the clutch and flywheel replaced at 118,000. But the judder persists.

The engine also has an acceleration flat spot at 1200rpm. But that existed before the judder materialised. Could that be related?

My local Volvo dealer and trusty local mechanic can't diagnose the problem.

If anybody has any suggestions I would be very grateful to hear them. Thanks.

If you are desperate and have tried everything , think about the Dual Mass Flywheel . are you sure that is ok? the vibration can affect the flywheel speed/position sensor readings as the flywheel is not rotating smoothly but in jerks ... an oscilloscope can be your friend here ..

what is it like if you engage the clutch to load the engine a lot without it actualy moving away ?

[JohnL]

Does your alternator have an overrun clutch, This will cause a lot of vibration at idle, possibly with a bit of belt squeak as well. But then disappears as revs climb.
John

[deltham]

Originally Posted by JohnL

Does your alternator have an overrun clutch, This will cause a lot of vibration at idle, possibly with a bit of belt squeak as well. But then disappears as revs climb.
John

Thanks for the advice. I'll check the clutch engagement and report back. I'll also take a close look at the alternator. Strange it only judders when it's warm though, which if it were dmf or alternator would cause vibration at all engine temperatures?

Part of the thread suggested by Cheshired5 talks about air in the fuel line. I have got a few bubbles. Could this be a problem? But again, presumably it would judder when cold too if this were a cause?

[deltham]

So when I engage the clutch in gear, the judder stops. Does this suggest the new flywheel was not fitted correctly? If so, that's going to be an interesting conversation with the mechanic.

[Clan]

Originally Posted by deltham

So when I engage the clutch in gear, the judder stops. Does this suggest the new flywheel was not fitted correctly? If so, that's going to be an interesting conversation with the mechanic.

If the idle rpm is still the same ( 850 rpm ? ) when you have the clutch partialy engaged without moving then it might indicate clutch/flywheel ..

[Symes]

I think Clan is right - when was the flywheel fitted??

When I bought my current d5 I knew the dmf was on its way out, when cold it would make knocking sound, and slight vibration that went away with clutch engagement, wasnt there when warmed up. When I replaced it (and clutch) as well as rotational play, there was play in the lateral plane and associated uneven wear on the friction plate.

[volvo for ever]

dual mass flywheel siezed?ive had thos twice before for idle miss

[deltham]

Thanks for the help with this.

As an update I've had the flywheel checked out....I'm told it's fine, thankfully. I had it replaced along with the clutch when I bought the car about 25,000 miles ago as both were knackered.

I've also ruled out the the MAF - when I unplug it the car goes into limp mode so I assume it's working as it should.

Perhaps a trip to the injector specialist again wouldn't hurt.

If I get to the bottom of it I'll post on here.