Breathing problem.

[Leloby]

I have the cup mod simple breather setup from rocker cover and sump pipe to a breather pot. It's all clean and clear. Last week oil pressure at 4.5 but blew dipstick out of tight tube. Then blew copper pipe for mechanical oil pressure gauge off at engine end. This 2mm pipe at 4.5psi dumped nearly entire sump over 6 mile drive home, blowing turbo seals to the bargain.

Great read eh? The question is, what's going on with breathing?

Can I blow compressed air down sump breather pipe to make sure it's clear?

What else could be causing oil pressure to appear ok but it's trying to escape up dipstick or anywhere else it can?

[LeeR5GTT]

I have the cup mod simple breather setup from rocker cover and sump pipe to a breather pot. It's all clean and clear. Last week oil pressure at 4.5 but blew dipstick out of tight tube. Then blew copper pipe for mechanical oil pressure gauge off at engine end. This 2mm pipe at 4.5psi dumped nearly entire sump over 6 mile drive home, blowing turbo seals to the bargain.

Great read eh? The question is, what's going on with breathing?

Can I blow compressed air down sump breather pipe to make sure it's clear?

What else could be causing oil pressure to appear ok but it's trying to escape up dipstick or anywhere else it can?

Lots of factors can cause high crankcase pressure I'm afraid. Have a read of this article, it may lead you in the right direction on where to start :agree:

http://www.ehow.com/info_12162215_can-high-crankcase-pressure-can-caused-worn-piston-rings.html

[Leloby]

Thanks, that's the kind of thing I was looking for. Forgot to say, newish pistons and liners yet compression is 118-128 min-max.

[James5]

I have the cup mod simple breather setup from rocker cover and sump pipe to a breather pot. It's all clean and clear. Last week oil pressure at 4.5 but blew dipstick out of tight tube. Then blew copper pipe for mechanical oil pressure gauge off at engine end. This 2mm pipe at 4.5psi dumped nearly entire sump over 6 mile drive home, blowing turbo seals to the bargain.

Great read eh? The question is, what's going on with breathing?

Can I blow compressed air down sump breather pipe to make sure it's clear?

What else could be causing oil pressure to appear ok but it's trying to escape up dipstick or anywhere else it can?


Your compressions tests lower than a std compression GTT in which you would be looking around 145-150psi across the board. (Have you got a performance cam in the engine?)

I take it the comp test you done was with the throttle wide open and a dry comp test whilst cranking the engine?

Have you done a wet comp test?

How old is the engine?? I note you have said that the piston, rings and liners are new? did you buy them and fit or was this someone telling you new?

How was your fueling prior to the incident RICH?? possible bore wash

I would be considering knackered rings, or even liner bore hone marks not very good.

Do the try test again make sure throttle butterfly is fully open (cable tie it open so you can crank and note results per bore), then do a wet comp test (put a teaspoon of oil in the bore you are about to test make note of results and post back on these boards.

[Leloby]

Thanks.
Test done with throttle closed - just followed gauge instructions.
Have receipt for pistons done before I bought it.
Will repeat per your instructions.
Thanks for now.