I have just noticed a slight tapping sound coming from engine bay.when I looked it sounded like it was coming from an injector,is this a sign of the injector being blocked or starting to fail or just a common noise.its not very loud think I may just be paranoid after problems I've had with the car. Also an unrelated issue when the car is under load pulling away.basically not quite enough revs there is a slight knocking.i believe this to be exhaust rubber or mount but cannot find anything.what else could cause this noise? Thanks
