Excessive oil pressure

[barneyrubble]

Seems my 1.6 jx td is suffering from excessive oil pressure. It has been burning lots of oil (think james bond getaway) spotting oil on to the tail gate. The turbo was swapped for a known good one and this has not changed anything, the engine is running REALLY well and is not breathing heavily nor is the puck blocked. When we revved it earlier today with the oil filler cap off, oil was shot out of it as the engine revved.

This makes me think I may have a oil pump relief valve issue, has anyone else seen this? Or can anyone else offer an explanation?

Any help very gratefully received as this is supposed to be a re-con engine and apart from this runs like a champ.

Best Regards

Matthew

[MGP]

Excessive oil pressure wont cause this excessive crankcase pressure will.
This is deffinatly a breather problem as any crankcase pressure should be vented. Blocked breathers will push oil out of the filler because it bolts to the sump below the oil level and it will stop the oil draining from the turbo because the drain is also below the oil level.
Run the engine with the breather puck removed and see what happens with the breathing it sounds like either a problem in the rocker cover or a breather pipe blocked or possible somehow the breather is fitted to the pressure side of the turbo.

[windy]

Could be over filled with oil.

Are you going by the dipstick marks or have you measured 4.5L of oil into the engine on an oil & filter change & checked the level on the dipstick?

If I go by my dipstick I would be about 1L over & these engines are very smoky if overfilled by that much due to the low turbo drain position.

[barneyrubble]

I have checked the dipstick by draining all the oil and then refilling with 4.5litre so I know the dipstick is correct. We have ran it without the puck in to see if it was breathing but it doesnt seem to be, what can be blocked to stop it breathing out of the puck?

Getting worried now!

[windy]

Is the "known good" turbo off a car, or another T25?
What works fine on a car can still leak oil through its seals on a T25, as they are fitted much lower.

[barneyrubble]

From another T25, even if it was that leaking oil it doesnt explain the oil/crank case pressure.

[windy]

In your 1st post you said it wasn't breathing heavily, which I took to mean there was no piston blow-by, because if you had this/excessive crankcase pressure you would feel it when you removed the breather puck, as the crankcase & cylinder head are internally connected.

[barneyrubble]

I cant feel it from the puck, but people have said that the only explanation for the oil being forced out of the oil filler is crank case pressure. So it would appear somehow it is not venting out of the rocker cover, I dont understand how that can be.b Apparently oil pressure would not cause this to happen

[windy]

As suggested by someone earlier have you taken the rocker cover off & checked nothing is clogged in there?
PS on my JX I have fitted an external block to puck breather from an AAZ engine, which might be worth considering.
I did this when I was suffering from excessive smoke on startup, but that was only cured when I fitted a new turbo core.

[barneyrubble]

Have removed the rocker cover and think I have located the drain hole in the lower left of the head. Can pass a piece of stiff wire through unobstructed all the way down into the sump. (it comes out like a dipstick), the breather port in the rocker cover also seems free flowing. If it is crank case pressure I down see how it isnt venting into the head. I am very confused!