Extreme oil pressure under load (2.1 Petrol)

[tstrangward]

Just bought this 2.1 pickup. Goes well but if one presses on for a while it suddenly drops a lot of oil (with accompanying smoke as it is burnt off).

We have investigated and found that if you leave filler cap off on idle there is no sign of crankcase pressure. Rev up and the engine turns into a pump and pumps a stream of oil out of the filler.

Have cleaned the breather tower.
Ran it on flushing oil and there was a definite mechanical noise from the engine which we had not noticed on standard oil. refilled with standard oil but it still has the pressure problem.

Any ideas of where to look next?

Thanks

Tim Strangward

[mahatmacoat]

Tim, if logic follows, the only way that the crankcase can become pressurized is if the gases are coming past the sides of the pistons through worn piston rings/pistons/bores. So changing the oil & flushing it won't have made any difference.

I'd check that the breather from the crank case into the inlet is clear & has not collapsed (the rubber pipe on some can get soft with oil contamination & age & close up). Failing that i'd carry out a compression check on the engine to see if it is simply old age.

Hope this helps.

[Simon Baxter]

Do you mean extreme oil pressure or extreme crankcase pressure, as they are worlds apart.

Sounds like a blocked breather.