E36 318ise Auto (M40) judder

I wouldn't use Slick 50, but it's your car, your choice.

If you have an M40 engine where you can't hear the valve gear from inside the car, leave it alone! This engine is notorious for valve gear wear.

My money is on an air leak, possibly via the servo, but any of the hoses could do it. Also you could have dirty injectors. Have you tried some injector cleaner?

Madrab wrote: To add to that that the clicking you hear from the head could be clogged injectors, when they are dirty/old the ball bearings inside can tick and can sound like noisy tappets. Rob

It's definitely tappety, the slick did help a little (only a little mind you), took it for a blast down the motorway and the judder isn't as frequent/agressive as it was, but its still most definitely there.

Dropped it into a mechanic friend of mines when I got back and both of us had a good listen under the bonnet. He's deduced that its missing  Systematically unplugging the H.T's one by one we found that number 3 is doing very little...

It's looking a bit more serious than an intake problem, and a damned site more costly as well i'm betting   Whats really getting me down is that the thing drives lovely, its just at standstill when idleing its all over the place.

Gutted and confused of the North.

Hi Slippy,

Yes mate, I did change the plugs just as a matter of course, although having said that, the ones I removed looked virtually new...

I've considered a blocked injector and thats yet to be investigated, but i'm thinking a compression test next in the search for more clues.

As number 3 didn't seem to be doing a great deal, i've also started to consider the possibility of a worn camshaft lobe, if the compression is low on one cylinder in conjunction with the rough idle, that could be one possibility, anyone disagree?

Cheers.

Hammer1 wrote: I guess he did the pulling each pluglead trick and see if the engine note changes and pulling off 3 never made any differences.So that would rule out plugs and lead on that cylinder

Spot on, Hammer.

Popping the lead off number 3 made no difference at all, and indeed its a compresion test next looking for more clues, the wierd thing is, if it was only running on 3 pots it should run like a bag of spaners but it doesn't.

It drives smoothe as silk and pulls really well, its just at idle when its misbehaving. I really am getting confused and frustrated with this damned car.

UPDATE:

Just back from the garage having finally made some time this morning, replaced the two hoses to the fuel rail and also the injector O-rings, plus given the spray heads a quick clean up and touch wood so far its driven smoothe as silk.

Reminded myself why they call them $tealers though! 6 quid for four flaming O-rings?!  blimey, only thing missing from the lads in parts was the facemasks and swords!