engine issue (possibly??)

Depending on how severe your 'jolt' is, I am pretty sure I have experienced the same in my car.

Especially from a cold start before fully warmed up, at traffic lights you can feel a slight judder from the engine from time to time. I just put this down to the characteristics of the M62 V8, but I could be wrong.

I assumed this was normal due to my car having done less than 40k miles and therefore should be good as new engine wise. Fingers crossed anyways!!

It would be interesting to hear from some other M62 owners.

Just a thought - it's not the auxiliary fan "kicking" in is it? I experienced this when I first bought my car and was a little surprised at the jolt, it's definitely noticeable but I've got used to it now


EDIT - just noticed you were on your way to get the aux fan fitted so it was unlikely ot be that
What gearbox have you got?

Jolt = Misfire?

M62 Engine.
In time, the cylinder head cover gaskets are prone to fail
Engine oil then compromises the spark plug wiring
Result is an occasional misfire which is felt as a jolt.

I had EXACTLY the symptoms you describe and replacing these gaskets cured it.
The engine now runs super-smooth, with NO stutters

Maybe this?

PS I've never had a jolt from either the AUX Fan or the A/C Comp (yes, they do work)
PPS There seem to be an awful lot of AUX Fan Threads/Posts at the moment....are they all becoming 'time/expired at once'

Could be the AC compressor cutting in and out in this weather.

8Tech.

my technologically inferior M70 drops aout 200rpm everytime the AC compressor turns on.

Violet, when are you next in Aberdeen? Fancy meeting up at some point? The 'jolt' can then be compared.

My m62 840 had a jolt once. usually at idle or dropping revs when coming to traffic lights. It started as a jolt as the engine cut then came back but got worse to the point of having to stop and re-start.

Was a cranckshaft sensor which cost about £30. Mine too was not used much by the previous owner and I had to initially iron out a couple of things that i put down to that.

Mine too drops or raises revs a little when a fan, i guess, kicks in and out. Its not a jolt though.

I will ask the garage about it as It is booked in for next week.

On my car I would describe it more as an intermittent stutter. I certainly do not notice ANY change in revs when fans etc.. are kicking in. Also there is no movement of the RPM needle on idle either, just a random little stutter from time to time.

I'm not concerned or even sure there is anything wrong.

Can anyone here with the M62 840Ci honestly say that their engine idles super smooth and absolutley never 'stutters' in any way shape or form? It is very hard to notice. I only notice it when the radio is off and sitting at lights etc...and even then it would never be noticed if talking to a passenger for example.

After doing a search I came across this post : http://www.8er.org/forum/showt…1981&highlight=rough+idle

Sounds like it may well be normal characteristics of the engine.

Sounds good, although I wont be home until Friday the 10th. Yet am home for 2 weeks from then.

Drop us a PM when you are around!

Hi Sparkles, yes my car has the same problem, (if it is a problem). I have a 1997 840 CiA, when sitting in the drivers seat and the car is idling, I can feel a small vibration, possibly a described as a judder, no change on the RPM. I thought it was a serious problem, but Gerry at PhoenixSports checked it out for me. It remained after changing the spark plugs and some leaking cam gaskets, and I suspect it is normal for the car. I am reassured that your car also has it, I suspect many more have it (atleast my dads Jag has a similiar vibration as well), Gerry has looked at it since and not seen anything to worry about, I hope that helps.