hi all,
first off i have an e36 3.0 m3 on an n reg,
ive been having trouble with it and wondered if some1 can offer some help.

the problem is,
it starts up fine, and used to drive fine for a while, then randomly it would drop a cylinder
then it started getting worse and happening sooner and sooner.
then after leaving it sit for a while, go cold, it would then be ok.

then i went out 1 day, got 5 mins from home then it dropped 1 cylinder, then another, then back to 6, then 5, then 4 then 6.... up and down throught them until it went, 6,5,4,3,2...dead, wouldnt restart.
i left it for 10 mins then bump started it, then manage dto get another 5 mins down the road all the time it was up and down from 6-3 cylinders, totally random, and couldnt let it idle.
i then put 6 coils from my dads car in and it ran fine, for 3 mins, then the same thing happened again.

its now got to the point where i cant drive the car.

it only needs to be running 3 mins on my drive then it drops cylinders 1 by 1 until it no longer runs and wont restart unless i leave it for a few hrs, then it does it all over again.


now ive tried a different set of coils, airflow on/off, new crank sensor, different ecu and vanos controller, had it in a garage and on a launch scanner, none of which has helped.

before this happened the car was in perfect order, low miles, regular servicing...


any1 got any ideas what it could be?

 

Fuel filter changed recently?

 

it is always the same cylinder(s) or different?

 

check the wiring loom that feeds the coil packs where it runs in the plastic cover over the engine. i had something similar-random misfire and it turned out to be some melted earth wiring(i think,cant quite remember).replaced the wiring and it was ok,in fact thinking about it the earth wire that goes on the last coil pack(no.6) wasnt connected and i presumed that had caused it.
worth a look.....

another problem i had turned out to be a completely blocked cone air filter,car would run but was flat as fuck-changed all sorts including air flow meter,inlet gaskets,injectors cleaned.......it was only when i was putting the filter back on i noticed how blocked it was!!! but it was my track car and i ran it without headlights in.

 

dont know what cylinders it is.
fuel and air filter are both ok, recently changed,
plus its now doing it at idle.
im pretty sure the earth is there as i remember refitting the coils and had to redo the last 1 as i left it off first time.

 

It might pay in the long run to get it on a rolling road, so the problem can be seen a lot easier with test gear/osciliscope, not sure all RR have these though, or a proper diagnostics centre.
tabetha

 

is it worse when cold?

i.e. is the oil to thick and holding a lifter open?

 

i have found a bmw specialist that has been recomended by a few people, he is ex bmw and has all their test equipment, so i will book it in with him, the problem is i will have to Aframe the car to heathrow, thats a 1hr drive at best so will b horrible on an a frame.

and no its not worse when cold, its better. it runs fine when cold, but very quickly gets worse, when its warm.