Not in the locost but a mates track car.

The engine is a 16v 2.0 mk3 Vw Golf engine.

Its had a full rebuild with new every thing.

Bearings / Rings / every thing.

The car starts and is showing 90 psi on the digi dash and on a manual gauge that his engine tuner had.
But as soon as the engine gets to about 50 deg water temp the oil pressure is dropping to 14 psi. The gauge goes nuts with low pressure warnings and the engine sounds crap as its not opening the valves. But there is plenty of oil around the cams. Again pressure has been checked against a manual gauge.

He fitted another new pump and its still doing the same.
Today he took the engine out and we started to rip it down.
It all looks fine as it should inc the big-ends and shells.

As this forum can answer most things I said I would put the question to you guys.


cheers

Not the same but I had similar problems with my sister in laws 5 cylinder Passat a few years ago . Tried a new pump, cleaned the strainer , filters etc but ended up sticking in a S/H lump

Yep ive told him to get another engine. He has been building it for the last 5 years or more and is well sick of it.

The new pump comes with a new strainer.

oil pressure relief valve ( if it has one ) sticking (read binding with heat) when the temp rises.
i.e. two dissimilar materials expanding at differing rates wth not enough clearance.

Maybe a bit of a wild guess.

Could be talking bollox, but I'm sure I've heard of a Golf head gasket being fitted wrongly. (Upside-down?) i.e oil feed or maybe drain back holes not aligning. You say oil pressure is getting to the top of the engine, but can the oil drain back to the sump?

Had something like this in the workshop many many moons ago, if i recall right it was the bushes on the oil pump shaft that were missing or too large.
Not sure if the above engine has the bottom mount pump that takes drive off the intermediate shaft though.

what should the pressure be at idle? A ford CVH is meant to be 14psi and my XR2 turbo lump runs that when warmed up. Doesnt sound that low to me but depends what VW specced originally?