Sharp rapping noise

[Proman]

hey guys well my vs is making a sharp rapping noise at idle.... I'm thinking its probably the lifters, the noise comes and goes, its not a heavy dull knock, just a sharp ticking kind of noise.... And i know it not the injectors, they tick fine..... any ideas??? The oil is looking a bit black too

[Brett_jjj]

Try removing the serpentine belt (fan belt) and then start the engine.(It wont hurt the engine to run it like this for a minute or two.) This test will confirm the noise is coming from the engine and not from one of the items driven by the serpentine belt.Engine noises can sometimes be deceiving as to where they are actually coming from.Theres a good chance its just a worn out idler pulley bearing,or maybe a noisy water pump bearing or even the serpentine belt tensioner pulley bearing.Ive seen this happen lots of times where the noise seems to come from inside the engine,but completely goes away when the serpentine belt is removed,and its ended up being an idler pulley bearing or similar.

[Proman]

great advice mate ill have a poke at it tomorrow cheers