Low down judder/misfire?

[Graham_The_Baker]

My 4.4 has developed a judder/ misfire at about 1.5-2k revs. Never above and not when cold. It only seems to happen under very light load and at low revs.

Has anybody had this before? I've had no EML and no codes are logged. My mechanic is hoping its a coil pack and said wait to see if it gets bad enough to bring on a EML.

Cheers, Graham

[X5Sport]

Coil pack would be an obvious one, or the wiring to it as it only happens at a certain 'frequency' with the engine vibrations at those revs.  Might be something going bad once warm and a bit of expansion has taken place.

Any fault codes showing?  Don't know if a coil pack failure would bring the EML on.

Richard

[Graham_The_Baker]

[quote="X5Sport"]
Coil pack would be an obvious one, or the wiring to it as it only happens at a certain 'frequency' with the engine vibrations at those revs.  Might be something going bad once warm and a bit of expansion has taken place.

Any fault codes showing?  Don't know if a coil pack failure would bring the EML on.

Richard
[/quote]

Hi Richard, no fault codes are showing but I think it's a coil pack. I'm going to France in four weeks and want it sorting before we go.

[Ubatoid]

Hi Graham, Try reproducing the problem but switch the gearbox into sport mode to see if it stops it. It sounds very like the torque convertor to me. Using sport

[IanP]

[quote="Ubatoid"]
Hi Graham, Try reproducing the problem but switch the gearbox into sport mode to see if it stops it. It sounds very like the torque convertor to me. Using sport
[/quote]

+1 on this.

[Ant]

What happened ?

Was it the coil pack or something else ?

I ask as yesterday I started home and under low revs, and at idle at the lights etc my car is sounding like a bag of bolts and I can feel the engine vibrating/juddering/rocking through the seat of my pants.

The engine light has come on.

I drive in sport manual mode most the time (not long had the car and refusing to go to an 'auto' at the moment, also I dream that I am getting better mileage by changing gears when I want to  ) and its the same in auto, sport auto or manual

At higher revs, 1500 and above it seems to feel much better, and on the journey home (its only 5 miles) the engine light went from solid to flashing.

Started it again today and it was solid engine light, drove to a small specialist in Portway as I didnt have his number, he wasn't in    got his number from a bloke in another unit and he gave me the story of why he did not work Saturdays but said it sounded like the coil pack.

Thing is, coming back from there, the engine light stayed on but the engine was running very smooth again, even at low revs.

Does this sound like the coil pack ??

Ta

[Ubatoid]

Sounds plausible. Get the faul read and it will give you a clue, ie missfire on cylinder ???. Coils do break down and cheap ones are complete waste of time. Try swapping them around to see if the missfire moves.

[Ant]

Thank you, the engine light has gone off now and it is running smooth again, so I have ordered one of the cable/scanner items so I can check for fault codes and see what that says