Popping Sound Out Of Exhaust

[abemcclellan]

i have an 94 325is and i've changed the plugs, and checked the plug wires, and changed the fuel filter. and i still have a bad idle and it soulds like it still missfires and the engine stumbles when it does make the popping sound. i put new bosch plugs and tightly in but not too tight. i need help and any suggestions on what my problem is. -Thanks

[bitcore]

There's a specifc torque that you are suppose to apply to the plugs to seat them properly. Do you have a torque wrench or can you borrow a buddys? I don't know it off hand but I'm sure someone in here will chirp up.

I can't really help you out much... but popping exhaust sounds like a simple backfire to me, unburnt fuel is entering the exhaust, which can probably mean you arn't getting full spark in one or two of the cylunders, sending the fuel inside the exhaust where it ignites and creates a loud pop.

[kestrel325is]

Have you checked the gaskets on the exhaust system? This can lead to backfiring, and the like.