james-wrx

o.k it's been worrying me for ages, the car revs and boosts fine, but about 6k revs it sounds a bit harsh, it's not a rattle more like a manifold loose or something, this only happens under load if i lift off at 7k revs it sounds o.k !
The knocklink will light up running 1 bar at about 6k if you wind the boost up to 1.3 bar the knocklink will light up at about the same revs
but it only seems to do it if you screw it round in third gear, i thought i would cure this by turning boost down to 1bar but the symptoms are the same whhatever boost i run
The only thing I havent tried is No boost
Could the bearings in the engine be on the way out ?
It's had a hard life with trackdays etc, the engine is a 2.2 Litre with forged crank, rods and pistons has covered about 10k miles since being built
This is starting to drive me crackers
The other problem is i work 6 days a week until 7pm weekdays and 6pm saturday so i cant get the car into a specialist
Any help or thoughts would be greatly appreciated i really done want to destroy such an expensive engine !

jaytc2003

iTrader: (1)

have you got an oil presure gauge fitted? If your big ends are on the way out you should in theory have noise and knock at any revs not just 6k. I suppose it could also be a noisy gearbox (3rd gear specific?), if the cars had a hard time then it is a possibility the box is on its way.

james-wrx

Thanks mate, The synchro on third is a bit dodgy but this is happening in 4th as well but only if you screw it all the way round to 7k !
It's got me very confused, im thinking the knock might be the FPR as it looks like it's seen better days, it was the walbro pump on it but FPR is an old one the gauge has got a bit of water in it, maybe it's bot maintaining the pressure at high RPM ?