E90 325i touring miss fire issue

[jcs25]

Hi all.

Had the car 5 weeks about to go back to the garage for the third time with a misfire issue. The car has had all 6 coil packs replaced and an engine flush last time it was there and has run fine for the last almost 3 weeks and 1000 miles.

Will another flush solve the issue, could the solenoids for the vanos just need replacing or could it be something worse. Am puzzled as it has run faultlessly for 1000 miles and then the same problem has come back. Any thoughts ? Should I just be getting rid and getting my money back? I do like the car nice spec and engine when it runs properly.

[mark.c]

jcs25 said:

Hi all.

Had the car 5 weeks about to go back to the garage for the third time with a misfire issue. The car has had all 6 coil packs replaced and an engine flush last time it was there and has run fine for the last almost 3 weeks and 1000 miles.

Will another flush solve the issue, could the solenoids for the vanos just need replacing or could it be something worse. Am puzzled as it has run faultlessly for 1000 miles and then the same problem has come back. Any thoughts ? Should I just be getting rid and getting my money back? I do like the car nice spec and engine when it runs properly.

Really at this stage you are just guessing, they need to plug it in and read the fault codes to narrow the cause down. Did they replace all the coils previously..IME garages will only replace the faulty coil, could be another one has gone. Did they change plugs? the coil extensions? etc...wait until they plug it in again and see whats what..and no a flush wont cure a missfire.

[jcs25]

Hi, they did replace all 6 coil packs 3 weeks ago. They have said it can be an issue with solenoids for the vanos as they can get clogged and the flush helps clear them out.

[mark.c]

Fair enough, I would think if there was a timing/misfire issue significant enough for you to notice with the Vanos it should throw a fault code.
To be fair, if the vanos is suffering because it is clogged up through long servicing intervals then a flush is likely to be only a temporary fix in my opinion.

[jcs25]

Ok cool, thanks for your help.

[philmots]

I can't see how an engine fluse could remotely affect a misfire..!

Did they change the 6 spark plugs with the coil packs? That's where I'd be looking first.

[Tonberry]

Which engine?

The M54 suffers from CCV issues which can cause major misfire.

[Smuler]

philmots said:

I can't see how an engine fluse could remotely affect a misfire..!

Did they change the 6 spark plugs with the coil packs? That's where I'd be looking first.

OP, this advice made perfect sense to me because, albeit on my E46 325i, after a complete coil pack change I had the same symptoms as when I had the faulty coils (and the same codes) but the only remedy was to change two problem spark plugs.
After that, back to normal.

[jcs25]

That was my thought as well change coil packs and plugs and all should be fine. Will get them to do the plugs as well.

Is rather strange and a worry that it has been fine for almost 3 weeks and a 1000 miles and then playing up again. They did allegedly send it to a specialist who said that it could be the vanos solenoids being clogged.

Engine is a N52 I believe as its early E90

[jcs25]

Just to give a clearer picture of the symptoms. The car initially runs fine on start up first thing. Then after about 5 mins into a journey will die at a junction and then when re starting will be misfiring at idle with a really lump idle car shaking. Will be smoother above 2000 rpm anything below that you can feel the misfire. If you put your foot on the clutch it just dies. Has been back to them twice previously and looked over by a specialist.

Edited by jcs25 on Friday 27th March 15:15

[jcs25]

Jus to update if anyone is interested. The issue was the VANOS and had to be replaced

[pdhokia]

jcs25 said:

Just to give a clearer picture of the symptoms. The car initially runs fine on start up first thing. Then after about 5 mins into a journey will die at a junction and then when re starting will be misfiring at idle with a really lump idle car shaking. Will be smoother above 2000 rpm anything below that you can feel the misfire. If you put your foot on the clutch it just dies. Has been back to them twice previously and looked over by a specialist.

Edited by jcs25 on Friday 27th March 15:15

I am having this exact issue with my car now. What mileage were you on when it happened? I'm surprised that the vanos system causes idling problems. Did you have to replace the solenoid or was there more involved? Thanks

[Touring442]

It can be vanos solenoids, very rarely the vanos units themselves and occasionally wear in the camshaft front bearing ledge - this allows pressurised oil for the vanos operation to escape.