[E93long]

Hi Everyone,

Would love some help please. I have an E93 - N53 engine. Suddenly while driving, I felt the car start to rattle when still / accelerating. Also don't have much power.

Drove home (wasn't far) - put in OBD 2 and got the following codes - PO306 Cylinder 6 misfire.

I swapped the coil pack for Cylinder 6 and Cylinder 1 - re read codes (after clearing) and got PO306 Cylinder 6 misfire and PO301 cylinder 1 misfire (as well as PO300 (multiple cylinder misfire).

I swapped the coil packs to their original postions, cleared codes, re-read and got the same as above. I then swapped cylinder 6 with 2, and now I have PO302 (Cylinder 2 misfire) along with all the others.

A friend who's familiar with BMW cars suggested their could be gunk on the coil packs and to buy electrical contact cleaner. I've done that but keep getting all 4 codes (cylinder 1,2 and 6 + multiple misfire code).

While cleaning coil pack 1, 2, 3 and 6 (had to stop because of rain) - I noticed oil on coil pack 3. I've also attached photos of the spark plugs from cylinder 1 and 6. Again I couldn't check all spark plugs / coil packs because of rain.

As a note - I changed the spark plugs my self back in July / August 19 (along with air / pollen / oil filter and oil).

My question is - Why am I getting 3 cylinder misfire codes now? Also the colour of the spark plugs do not look right to me - It's only been 6 months and they look horrific. What's happening do you guys think?

Kind regards and thank you for your help.

Spark plugs from Cylinder 6






Spark plugs from Cylinder 1




Also not sure if it's relevant but I've found black sludge (oil I think?) under the oil filter housing (blue circle). I recently changed the oil filter because of this to no avail.

[Captain Kudzu]

My N52 e91 started having some horrible bucking and shuttering. I thought the automatic transmission was acting up. It ended up being Misfire Cyl 6.

Took it to a buddy's shop.

Found 2 coils were mismatched, old ones. They replaced the 2 old coils. Tested the car. All good.

Has been fine for 8k miles so far.

So, I would just change the coils.

I think they are fairly common failures on these.

Good Luck.

[E93long]

Originally Posted by Captain Kudzu

My N52 e91 started having some horrible bucking and shuttering. I thought the automatic transmission was acting up. It ended up being Misfire Cyl 6.

Took it to a buddy's shop.

Found 2 coils were mismatched, old ones. They replaced the 2 old coils. Tested the car. All good.

Has been fine for 8k miles so far.

So, I would just change the coils.

I think they are fairly common failures on these.

Good Luck.

Thank you for your reply. I ended up chancing it and changing all the coil packs. Fixed the juddering!