Hi.. i have a knocking sound from the engine and its only occures when i accelerate. There isnt any knocking when the engine is idle. Also the sound seems to increase when i switch on the AC. I replaced my spark plugs recently and noticed oil in one of them. I guess that means i have a bad valve cover seal. Is the knocking associated with the oil leaking or is it something else.
Thanks for the help
Raj
Its a 1996 nissan sentra with the 1.6L engine.. i forgot to add!
Raj wrote:
Most engine knock sounds that are due to wear mostly get quieter when accelerating as the loading takes up the play, so I don't think it's bearings or a worn piston skirt or bore unless someone has experience of the problem with your engine specifically. I've known it though just before a crankshaft snapped in half but that's so unlikely forget it.
Perhaps it's heavy pinking, that can sound like a light tinkling if it's only just doing it but like a hammer on an anvil at its worst and will be much worse when accelerating especially if the engine is hot. I doubt if the oily plug is relevant unless it's causing pinking (unlikely). Ignition timing too advanced, wrong fuel grade, weak mixture, wrong plugs, lots of carbon in the combustion chamber can all cause pinking.
Sometimes it's just something loose somewhere like exhaust heatshields, or engine mounts too floppy.
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.