Low oil pressure

[Barn]

Help please.
After an expensive steering overhaul, I finally got my car back together.
I filled the cooling system back up and was just running the car up to temperature, as the car got warmer the oil pressure got lower and the the warning chime sounded. The oil pressure was only around 1 bar maybe lower and the top end started to get a little rattle. I know the senders are good they are both new genuine Audi parts. The oil pressure is always at 5 bar from cold, I'm running 10w/60 Mobil 1 with a genuine filter.
Today I removed the sump to check for a blocked pick up tube but no blockage and no sludge, infact inside the engine and sump was very clean indeed. The only thing I noticed was that the rubber intake manifold on the end of the pick up tube was slightly deformed inwards towards the gauze !
I am not sure what to do next, perhaps the oil pressure relief spring has gone weak or maybe the oil pump has worn. I have found a new Audi oil pump but I think its a diesel one, part no. 034 115 109.
Any help would be awesome, there is no big end noise and as soon as the engine cools it runs beautifully.

[UrS4boy]

Oil Pump, Temperature Sender, Pressure Relief Valve Info.

I can't find a listing for a 034115109 oil pump. I did find images of one and it looks a bit like a 3B oil pump (you didn't say which engine you have).

"The oil pump is driven off a washer on the nose of the crankshaft (Item 2, PN 034105177 below). The oil pump is a gear pump which means the oil pressure is created by two rotating gear wheels as their teeth intermesh, causing pressure as the grear teeth try to compress the mostly incompressible fluid (the engine oil). If the pressure gets too high for some reason in the pump, the pressure pushes against the pressure release piston and spring, releasing pressurized oil back into the oil pan. Note: The ADU in the RS2 originally used the 054115105D oil pump from the AAR 10V five cylinder gasoline engine instead of the more common 054115105E that the AAN and ABY use. However, the 054115105D was dropped on Jan.11, 2002 in favour of the AAN/ABY oil pump (the 054115105E). The 3B (and NM and 7A) use a 034115105B oil pump."

REFERENCE: http://forums.quattroworld.com/s4s6/msgs/93029.phtml

3B 034115105B oil pump:



The "Cap" on the oil pick-up should not be inverted. Sounds like yours is getting sucked into the pick-up tube, blocking oil flow to the pump



Check the strainer under the cap for debris if you haven't already

[Barn]

Excellent info, My car is an ADU RS2.
Your right the oil pump should be 054 115 105E.

[quattro-nick]

you can check the oilpressure with a mechanical meter on the location where the sensor sits
also you can remove the oil pressure relief spring to check it.
and you had this problem not before the steering overhaul?

[Barn]

When I first got the car it did this, but as soon as I changed the senders it fixed it.
With a gauge on it while driving with a hot engine it was just over 2 bar.
How do I check the relief spring, is there a measurement.

[quattro-nick]

i dont know,i think you only can see if the spring is not broken or if the valve is not jammed in the house.
is the sump still removed? if so,check your main bearings and rod bearings for damage to be sure

[Barn]

The Spring is in one piece I'll have to find out what length is should be, the piston was free moving.
I think your right it's time to check the bearings.

[Kieron20V]

I can't find a listing for a 034115109 oil pump. I did find images of one and it looks a bit like a 3B oil pump (you didn't say which engine you have).

"The oil pump is driven off a washer on the nose of the crankshaft (Item 2, PN 034105177 below). The oil pump is a gear pump which means the oil pressure is created by two rotating gear wheels as their teeth intermesh, causing pressure as the grear teeth try to compress the mostly incompressible fluid (the engine oil). If the pressure gets too high for some reason in the pump, the pressure pushes against the pressure release piston and spring, releasing pressurized oil back into the oil pan. Note: The ADU in the RS2 originally used the 054115105D oil pump from the AAR 10V five cylinder gasoline engine instead of the more common 054115105E that the AAN and ABY use. However, the 054115105D was dropped on Jan.11, 2002 in favour of the AAN/ABY oil pump (the 054115105E). The 3B (and NM and 7A) use a 034115105B oil pump."

REFERENCE: http://forums.quattroworld.com/s4s6/msgs/93029.phtml

3B 034115105B oil pump:

Being @nal here, but you're the most @nal chap on here.

That's not how a gear pump works.

Fluid flows around the outside in a gear pump, not through the middle. Check the inlet and outlet ports.

Sent from apollo 13 using tapatalk

[Error404]

10w 60 is too heavy. You might be getting starvation from the oil not draining back to the sump fast enough.
Try 5w40 or max 10w50

[A1QSHIP]

Technically the oil pump is a Gerotor style pump.

https://en.wikipedia.org/wiki/Gerotor

The oil OP is using is not the issue. I have seen this problem on a friends car. 3b transplant in to a 7a coupe. Problem was as OP described that oil pressure was OK until the engine warmed up. After about 50 miles of easy driving the oil pressure would drop low enough to trigger the low oil pressure warning buzzer.. Turned out to be that the oil pump drive tang on the crankshaft would loosen up & the pump would not be driven. Believe this has happened to another forum member here recently.

[Barn]

That could well be the problem. Is the drive tang a press fit or is it keyed ?

[quattro-nick]

press fit,i have mine replaced in the past
just heat up the new drive gear,put it on place en let it cool of
and this is the thread that A1QSHIP means

http://www.s2forum.com/forum/showthread.php?t=78580

[UrS4boy]

Being @nal here, but you're the most @nal chap on here.
That's not how a gear pump works.

Fluid flows around the outside in a gear pump, not through the middle. Check the inlet and outlet ports.

I must also be the most confused @nal chap on here then. I am quite sure that I never said that the fluid (oil) flows through the middle. If I did, I need you to please point out where I said it because I am not seeing it. Then I will correct the incorrect text.

Also, are you saying that the meshing of the gear teeth is not what creates the oil pressure?

[Kieron20V]

I must also be the most confused @nal chap on here then.

Lols, I think we are both confused.

Also, are you saying that the meshing of the gear teeth is not what creates the oil pressure?

Not in a gear pump. You said it was a gear pump, it's not. Different story.


Let's shake hands and move on.

HNY

Sent from apollo 13 using tapatalk

[UrS4boy]

Not in a gear pump. You said it was a gear pump, it's not.

Sorry. I can't let that pass. It certainly isn't a centrifugal or piston pump. I see inter-meshed teeth. I will concede not a "gear" pump only if "Technically the oil pump is a Gerotor style pump" is more correct.

Incidentally. The wiki on Gerotor said "N" and "N+1" teeth. I count 16 teeth on the inner gear and 19 slots on the outer gear.

Just sayin'

Proper Gear Pump: