Just had a pretty high spec XE built along with a brand new oil pump.

On starting the engine it showed an oil pressure of about30-35psi on and around 3-4 thou rpm which then proceeded to drop off to hardly anything so we stopped the engine and dropped the sump for a look.

Only thing we found was the o ring on the oil pickup pipe was a little shallow so fitted a new one and restarted.

We then got around 35-40 psi and no more upto 4 or 5 grand rpm.

I have now drilled and tapped the end of the relief valve with an M8 bolt so i can up the pressure manually by compressing the spring.

We have now seen after a few turns 60-65 psi so it seems to be working.

2 questions here...

1.Anyone else had this trouble with an XE or similar?

2.What oil pressure do i need to be seeing at 900/2000/5000 rpm?

Thanks,
Rob.

Oil Pressure Relief Valve is a common fault. Not seen it myself, but heard about it lots.

You can get Nylon bits from SBD i believe

Yep pressure relief valve is a very common problem and I have had it myself a couple of times.
My pressure is usually around
80psi cold idle
40 psi hot idle
and 75 to 85 during normal running.

Never heard of drilling/tapping the relief valve?????

Good point to realise, to much oil pressure will reduce horsepower.

Dyno proved

Oil pressure releif valve is a fairly common one on the XE
SBD do the Nylon plunger up-grade

Slightest bit of muck that finds its way from the bottom of the sump through the oil pick-up gauze goes into the oil pump

One thing i saw once was a mate fitted a modified sump & pick-up, and the head of the oil pick-up pipe grounded on the inside of the sump which gave him hardly any oil pressure

Thing to be careful of is that if there ain't much oil pressure at the Bottom of the engine there won't be much in the Cylinderhead

Oil pressure should be Minimum 1.5 Bar when Hot

[Edited on 22/1/11 by perksy]

The nylon SBD spring replacement is to prevent sticky springs on older pumps.

However this is brand new and defiantly not sticking at all, had it to pieces about 10 times

Drilling and tapping the rel valve is common in C20XE rally engines.

Thanks for the comments anyway.