I have a MY94 WRX RA with the stronger!!? closed deck block (EJ20)

Two years ago I had a piston go on me and have had it replaced.

Last week noticed a knocking noise which got louder at 3500 revs and thought it was the heat shield again.

Today popped the bonnet and revved the engine, sounds like it is coming from the inside of the engine on the drivers side (opposite side to the chaged piston). The noise gets louder the higher the revs. It is a noise that goes to the speed of the engine if you no what I mean.

I have recently checked the compression ratio and all seems fine there is no smoke plumming out the back put it does smoke a little bit when driving hard but it has always done this.

Not sure what it could be but thinking it may be one of the following
1) Big end
2) Piston Slap
3) Tappet/Lifter
4) Cam

I am very worried and not sure if I should drive it just in case it gets worse.

Any Help appreciated

Thanks
Scott

:( Sounds possibly big end. If you drain the oil, you will soon find out. If it's gone then there will be bits of metal in the drainings.

cc

I agree sounds like bib end>>
I had this problem last year be careful not to run it if thats the problem,any loose parts get pumped into turbo and that will need replacing too.
Seek help rappido. sorry to hear this mate....

Sounds like big end...Sorry been there myself.