I can not seem to diagnose what is causing my #1 cylinder injector to have a rather loud nailing noise. I was suspect of the injector itself so I switched it with the #4 injector and the nailing is the same still at #1.
When you loosen the fuel line at #1 the nailing goes away but of course you are now leaking fuel and skipping.
The nailing started a few months ago during a cylinder head gasket episode where the gasket was blown pouring oil into #1 cylinder. That has been corrected with the new head gasket and the car runs great except for the slight skipping and white smoke at cold start up that clears up after a couple minutes.
The nailing noise in #1 did not use to be there and I would like to know what causes this phenomenon and what can be done to clear it up?