In Reply to: I had same ping from Bosch +4 repair bill $$$ posted by Kenny on October 16, 2001 at 18:53:53:
I think the Bosch +4 are awful, overpriced and offers very little advantage over regular NGK's or regular Bosch Platninums..
The pinging sounds ended up being fouled up Spark plug adapters, and a faulty ignition coil in one of the cylinders... Was not cheap to fix..
Also what about the NGK BKR6EK.
The reason I ask is because I have a pinging problem with my '95 525 touring when accelerating from a stop. I've de-carbed the engine and run several bottles of injector cleaner. It is getting better. One of the things I did however, when I first started getting the problem was change the plugs. It looked like they were still original (bought car at 45K and it now has 50K). I put the Bosh+4's in even though about 1/2 the people here don't like them.
Since the problem is getting better, I'm wondering now if the only remaining thing that could be causing detonation is the plugs themselves.
I've not yet had a chance to take the car on a good long trip since the pinging started. That may fix it by itself. Hopefully in a couple of weeks I'll be able to take it on a 200-300 mile trip.