I recently purchased an 04' SE7 with 113,000 miles on it. I purchased it from the original owner who had every scheduled service performed and anything else that was needed meticulously and documented by the local LR dealer. I feel it was a great find. It needed a head gasket (exhaust leak). After the head job, I began getting multiple mis fire codes.I have been reading many of the posts regarding the multiple misfires code. I recently replaced both head gaskets, machined the heads, all gaskets above the heads, added 8MM Magnecor wires, replaced Bosch Iridium plugs, replaced all radiator hoses, flushed the coolant and replaced, replaced the battery, changed the oil over to Castrol GTX synthetic blend 10w40, bosch oil filter, rear ceramic brakes, and replaced all factory hose clamps. I got it running and all seemed well, watching temps etc. I hooked up my Actron code reader with live feed. Temperatures holding nicely just under and around 200. The problem is, I feel a slight "flutter" in the engine. I drove it, it seems fine. At idle though the flutter is slightly noticeble. It threw a check engine light. I read the codes and it said multiple mis fire, cylinders 5 & 7. I checked all of the wire connections on the plugs. Everything seemed tight. I reached the few that I could on the coil packs to make sure they were seated good. The ones I could feel, semmed ok. I cleared the codes, and drove it some more. Still light flutter at idle, otherwise nothing seems out of order. Then a code indicating cylinder 5 misfire. Again checked the connections, and checked all vaccum lines. Everything seems ok. I cleared it a last time and drove it. After a while codes cylinder 3 & 7 showed up! The misfire is moving, which leads me to think it is not the coils. I am not finding a vacuum leak, and other than the light flutter all is running well. I am pulling my hair out (what is left of it). Could it be a camshaft positon sensor? I am at a loss. PLEASE HELP!

 

When was the crank position sensor replaced last?
That would be my next move before tearing the engine back apart.

 

I have every service record since new and do not see that it has ever had a CPS installed. Would that cause misfire codes?

 

It might, it controls the spark, when it fails it just kills the engine 98% of the time.
It is a fairly cheap part, $70 at a local autoparts store and it is a normal fail item.

 

And when swaping it out be sure every nut and spacer goes back in same order. See attached.

 

One thing that will help us is the actual fault code numbers and not your version of what they mean.