Excessive oil pressure

[willholmania]

I think I may have excessive oil pressure (I'll be checking as soon as my mate brings the gauge round he has). How easy is it to get to the oil pressure relief valve?

[terrybullwon]

What makes you say excessive?

[Rusty]

Should be about 2 bar at idle and 100deg oil temp. Off the clock at startup isn't uncommon.

[S2central.net]

Yeah don't be worried if you see 5bar oil pressure on cold start - thats a good thing !

[willholmania]

I think it may be excessive because oil's being forced past the seal of the turbo. The turbo's been rebuilt and has been checked again after this problem manifested itself. I fitted a 2mm restrictor in the feed line to the turbo (I'm not using the original Audi feed lines) but the amount of oil coming out of the turbo drain still seems a lot to me. I was under the impression it should be a trickle not a river. This is an ABY engine in a Ur quattro and I've never had it running before. The bores are immaculate, as is the head. But the thing smokes like it's done 800,000 miles and the exhaust turbine housing is full of oil. The car doesn't have an oil pressure gauge so I have no idea what pressure it's making but having had the turbo off and back to the specialists for double checking I'm trying to work out why the oil wants to go past the turbo seal and into the exhaust pipe, rather than down the drain and into the sump.

[Rusty]

Is it a GT turbo? There have been a few of them that have done this, Lynx springs to mind.

[willholmania]

The turbo is the original KKK from the WR engine the car had but with a bigger compressor wheel in it. It's been completely rebuilt - and double checked.

[willholmania]

Can anyone please tell me whether I can get to the oil pressure relief valve?

[aelred]

I can give you a S/H one

[twoqu]

What oil return pipe are you using? I thought I had read you cobbled one together in PPC style. If there is any significant restriction in the return side, say a loop somewhere where there shouldn't be, then thats a likely cause as the drain uses gravity not pressure.
For some reason the earlier KKK 26 does seem to cause problems. Besides the fact even if its a hybrid, the original KKK24 is much better suited right up to 300bhp as proved on here! Might be worth sourcing the correct pair of lines, both feed and return.

[stiglet]

The oil pressure jiggery is on the bottom front end of the block. Drivers side IIRC. There is a sender attached to it.

[Mikes2]

it's in the oil pump above the oil temperature sender

[Acidburn]

What oil return pipe are you using? I thought I had read you cobbled one together in PPC style. If there is any significant restriction in the return side, say a loop somewhere where there shouldn't be, then thats a likely cause as the drain uses gravity not pressure.
For some reason the earlier KKK 26 does seem to cause problems. Besides the fact even if its a hybrid, the original KKK24 is much better suited right up to 300bhp as proved on here! Might be worth sourcing the correct pair of lines, both feed and return.

[willholmania]

Yes - the oil return is just a big hose. But it's as big as it can be and it curves nicely down to the return union on the block. Can I get the oil pressure relief valve out without even taking the sump off then?

[stiglet]

Yes you can get to the valve quite easily. At least on the KV engine you can, which i think is pretty much the same. It just unscrews from the bottom of the block and the valve plus spring will come out with it.