Dropping In And Out Of 5 Cylinders R34 4D

[yesitshim]

I own a 1998 4 Door R34 and in the past few weeks i have noticed this problem and i have taken it to two mechanics who are unable to solve it

Either when i start the car, hot or cold, or even during a drive, the engine drops to 5 cylinders and loses significant power.

At times it will go back to normal after a few minutes, others it wont be until i turn the car off and wait for 5-10minutes.

I had the taken to two mechanics and both suggested it was a cylinder problem, even happening when they gave the keys back to me, but when they came over and we stuck it into drive it unfortunatley at that time, went back to normal.

They told me they cant solve it unless its happening while they are inspecting it.

I have been told it could be my coil packs or even wiring....

Does anyone have any possible solutions or experienced the problem?

[mad082]

does the check engine light come on when the problem is occuring?

it does sound quite like a coil pack issue. might be worth seeing if you can find a member on here in your area who has a consult cable and is kind enough to let you borrow it to check the fault codes on the ecu.

[Spurdo]

+1 for coils. if so then it'll just be one thats cutting in and out when it feels like it. you could buy (or just borrow) one good coil, then use it to replace each coil and keep swapping them over until problem goes away, then you've found the baddie.

OR, this way is probably easier actually. leave your coil cover off, then when the fault happens, stop the car, lift the hood with the engine running and disconnect the plug on top of each coil. each one you unplug should stop one cylinder firing and you'll hear the engine sound even worse than it did before, plug it back in if so. try each coil until you find one that makes no difference i.e the engine will sound and run the same as it was. if you find that unplugging one particular coil has no effect on the running of the engine, then you've found your bad coil/cylinder. replace that coil with either a new one or one you know is good. go for a drive, if problem doesnt happen again, problem fixed. if it still happens, then its not the coil.

not sure ecu would even have a fault code for a bad coil would it?

[yesitshim]

both of you were right, it was the coils. thank you very much for your help

I followed your steps jonboy and managed to solve the problem, i was pretty lucky as i got it right on the second attempt. I have since replaced the coil and all is working as it should!

thanks once again