Oil pressure too high?

[Deluks]

Have carried out an oil pressure test on my old 1991 Polo (AAV, Petrol, SPI, 1.3) which has been sat in the garage for the last 2 years!
Oil light and buzzer were on, the pressure is supposed to be 2 bar according to Haynes, but is coming up at 4 bar. What are the likely causes?
Have found out that the oil pump doesn't have a relief valve built in, so it can't be that. The oil and filter have done 0 miles, although have been sat there.

 

[JulianP]

Nothing wrong with that I wouldn't think, 4 bar is about 60psi which I would say is fine for a cold engine in good condition with fresh oil.

The Haynes book of lies probably quotes a figure for an engine at idle with hot oil

 

[Belle427]

Definitely worth changing at least the oil if it has been standing 2 years even if it has been standing.

 

[Mursal]

Connect the wire that should be on the oil switch to the engine block and the light/buzzer should go off? If so and when reconnected they still come on, with the engine running, you need a switch. Or its blocked, from storage.

4 bar is something we dream off, definitely nothing to worry about. Very unlikely that the oil pressure relief valve would stick closed. But the oil pressure drops when hot, doesn't it?

2 bar would be their minimum value required or you may have a gauge that needs calibrating

 

[lillianhofstader]

I think for this you should check your fuel injector

 

[Burnerman]

You are definitely on the ball, Lillian.
John

 

[lillianhofstader]

What you just said???

 

[Deluks]

Had probs with light and buzzer, changed clocks from another Polo, buzzer went away, light still on.
Grounded switch wire, light does not go off. Tested with warm oil.

Wanna eliminate everything else before getting the head off.

 

[Deluks]

You are definitely on the ball, Lillian.
John

Was this sarcasm, or do I really need to check my fuel injector?

Thanks to all replies so far

 

[Burnerman]

Just my attempt at humour, mate
So whats happening now.....with the engine running, is the oil light still on?
(Never knew these cars had a buzzer.....new to me, that one).
John

 

[Mursal]

Might I ask, what are you going to do when you take the head off?

When you earth the wire going to the oil pressure switch to light comes on if working correctly. When you disconnect the wire the light goes out, if working correctly?

Oil pressure light still on equals low oil pressure and the gauge says 4 bar, a bit of a contradiction don't you think?

Yes, John does standup ............................

 

[JulianP]

?
(Never knew these cars had a buzzer.....new to me, that one).
John

Not many survived for long as the buzzer was always giving false alarms and got disconnected. I think the pressure switch had two outputs - light and buzzer and the buzzer worked in conjunction with some electronics that put engine RPM into the equation. (I think.....)

 

[Deluks]

JP: I'd heard about the buzzer issue, so might have to disconnect that.

Murs: Light stays on regardless, it is specifically a low oil pressure light? I think it's just on because the pressure is not what it should be.

Getting the head off was gonna be to check the oil galleries for blockage and to make sure the gasket is correctly aligned.

John: High pressure could be a concern according to this:

http://lubricants.s5.com/oil_pressure.htm

It also mentions injectors


Sorry I haven't had another go at the car since I made the OP.

 

[Burnerman]

Sorry my PC wouldn't allow me to access that link, but I would strongly suspect that its just the pressure switch at fault.
If the engine was so worn that oil pressure couldn't establish, it would rattle and knock like hell. The only rattly thing about these engines are the hydraulic valve lifters.
There is only one feed through the block and head to the cam, front left side of the block (which is where the oil leaks start as a rule). Running the engine with the cam cover off should get you a good soaking!
John

 

[Astra99]

Slightly off-topic, but relevant.

Many years ago I rebuilt a Vauxhall Victor engine. The oil pump looked fine, no excessive wear etc etc. I started it up, and the oil pressure built to 60psi on idle (cold) and over 100psi at 2500 rpm (approx.). Yes, the blasted relief valve (mounted on the oil pump) was jammed shut!

Needless to say I said @**$&@@* and took the sump off (good job it would come off in situ) and replaced the oil pump. Pressure back to normal.

Don't forget that excessive oil pressure can cause oil seals to fail and "wash" the white metal from the crank bearings!