I've a 518i E34 1991 with an M40 Engine. It's an European model and there is a lot of problem like clicking sound from the engine when driving uphill.
It has a problem when trying to start the engine when it cold as it takes time to idle itself. I have already changed the idle stabiliser valve but nothing seems to have changed and there is also a problem when using electrical devices like the front lamp, electric windows etc... as the idle speed tends to go down.
I would like to know which are the best spark plugs to use for this engine
Is there anybody who could help me.