My 1995 3.8 m5 I am afraid is in need of a rebuild, in november 2004 my car developed a missfire, which slowly got worse, I traced to Nº 5 plug, and upon examination I found the extension stem for nº 5 coil perished and with signs of tracking to earth.
Replaced the plugs, repaired the stem with insulating tape, whilst I ordered a replacement form the local Bmw agent and the engine apeared to be running ok.
My father borrowed the car for a day trip and returned with the car running on 5 cylinders, I assumed my temp repair on the coil extension stem was the culprit, when I checked, I found that the engine had munched the spark plug on nº 5 cylinder, things did not look good.
I replaced the spark plugs again and crossed my fingers hoping the engine had survived unscathed, no such luck, Nº5 spark plug would oil up at low rpm.
My suspicion was that in digesting the central electrode of the spark plug the piston was damaged in process or perhaps the head damaged, it would require an engine strip down to investigate, as the m5 has really small spark plugs and I could not check the cylinder with an endoscope.
As the saying goes it never rains , it pours, well all this coincided with serious problems with my 2 partners at work, which eventually led to us spliting up, and a huge financial burden, and to top it off, I split up with my other half.
All these problems resulted in the car remaining in the corner of my workshop awaiting for me to have time to strip the engine down and investigate. and the time has finally come,I decided to remove the cylinder with the engine in situ, after 2 days of headscratching the cylinderhead is finally off,(I think its probably quicker to remove engine from car 1st, and then strip engine) and Nº 5 piston doesnt look pretty, and the bore is scored.
So next question, Can anyone recomend pistons asides from the originals which cost over 2000 €, in which case I would try to obtain lighter racing items.
I would also like to get the head gasflowed whilst its off, can anyone recomend a reputable co or person who knows whats he doing, I moved to spain 8 years ago and have lost touch with the uk tuning scene. but I think my best bet is to have the head done in the uk.
lightweight flywheel again any sugestions.
and I might fit schrick cams aswell if the budget allows.
As you can see if am going to rebuild the engine I might aswell try to improve it whilst i am at it, more power please
Next,I will remove the engine and continue with the strip down.