Too much pressure in engine/overheating

[Cammy]

Can this be caused by a damaged inlet manifold?

[raunchz]

Coolant pressure? Crankcase pressure?

Had a 'sniff' test done?

[Cammy]

Crank pressure, there is a backfire from the airfilter upon high revs

despite too much pressure the car goes very well and is quite quick, no smoke, sometime smells of petrol But that's it - no sniff test done yet

[raunchz]

Standard injectors, Ecu etc?

Any funny clicking from the Ecu?

When does it backfire through inlet, at a certain rpm or when you rev through an rpm? What colour are the plugs, I'd assume they are all black? They all the same colour or one blacker ?

[Russ_16v]

I doubt excess crankcase pressure would cause a pop through the filter, how bad is this pop?

[Cammy]

Standard ecu and injectors, the backfire is loud (loud meaning it's louder than if I were to not have an exhaust on my car)

[Cammy]

And backfires when hitting limiter

[Stevo123]

I am thinking damaged valve/valve gear, and when your on the limiter it is not back firing as such just the limiter is stopping the spark plugs from firing in a vein attempt to stop you from killing your engine. Best to change before limiter mate.

[Cammy]

Hmmm, the engine does sound tappy - but i'm sure that's just the cambelt needing changed, the cars at 76k and there's no history of cambelt change ever - could something be off? I.e cam has slipped and retarded/advanced itself?