Oil pressure, or lack of!

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Mon 30 Jul 2001 10:12
Oil pressure, or lack of! - Mark
Hi,

My car (1988 Audi 80, 1.8 carb) has developed a really annoying (and worrying) habit of showing me the low oil pressure light at higher engine revs (i.e. about 60mph+ in 5th). My first port of call was changing the sensor as it had begun to leak a bit of oil. No joy there. So I decided to go the whole hog and change the oil pump. Besides the fact that the engine now runs a little smoother (the pick up of the old pump was a little clogged with carbon deposits) the low oil pressure light is still plaguing me!

To me it seems like the high revs mean the pump's pulling more oil out of the sump and perhaps it isn't getting back down into the sump quick enough to be pumped up again. Or something similar. So if anyone has any idea where my next port of call should be do you think you could share?!

Thanks in advance,
Mark
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Mon 30 Jul 2001 11:32
Re: Oil pressure, or lack of! - Michael
have you checked the oil level and changed the oil and filter? I would obtain an oil pressure gauge and check the actual pressure (you can connect it to engine instead of the oil light sensor) or ask a garage to do it. Don't take chances with oil pressure, it has a habit of being terminal for the engine.
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Mon 30 Jul 2001 11:38
Noisy! - David Lacey
If your engine was low on oil pressure, then I'm sure the hydraulic tappets would surely be rattling due to lack of oil pressure?
Get the oil pressure checked at a competant workshop with the correct equipment (Most decent 'shops should have it)
I'm not sure of the actual values but I'm sure they would be able to interpret them for you and reference them against data in the Autodata manuals.
There are two oil pressure sensors on this engine - did you indeed replace both?
One is situated on the end of the cylinder head and one is on the oil filter housing. They are not the most reliable sensors anyway..

Rgds
David
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Mon 30 Jul 2001 16:05
Re: Noisy! - Mark
Hi,

The oil and filter were about 2,000 miles old when I changed the pump and sensor, new oil and filter went in at the same time. The tappets aren't noisy (I know that sound well from an older car!) I am also of the mind that I would surely feel some difference in the running of the engine if there were insufficient oil pressure, i.e. more friction in the pistons?

I only actually replaced the sensor on the oil filter housing, I didn't realise that there were two. Perhaps that should be the next thing I try. It's MoT is due in about 3 weeks so if that doesn't fix I'll take it in and get them to do a pressure test as suggested, if it is serious it'll be a short lived VAG engine with only 112k on the clock!

Thanks,
Mark
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Mon 30 Jul 2001 16:56
Sensor - David Lacey
Yep that sounds like it - change that sensor in the cylinder head, the opposite end to the cambelt and I think all will be well
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