Average oil Pressure

Just trying to get an idea if my car is ordinary or not.

I recently was able to hook up an an Oil Pressure Gauge to my MK2 GTI Golf (running a 2 litre 8valve engine)

When at operating temp, at idle the engine has 20PSI+ of oil pressure.
At 2000rpm the engine has 60+PSI of oil pressure.
It max's out at 65/75 PSI at any RPM above 3,000.

Its running a 20W50 oil and has done 250,000km easy.
Do oil pressure figures like these suggest that the engine is running happily or does this sound high?

Thanks

ryana89 wrote:Just trying to get an idea if my car is ordinary or not.

I recently was able to hook up an an Oil Pressure Gauge to my MK2 GTI Golf (running a 2 litre 8valve engine)

When at operating temp, at idle the engine has 20PSI+ of oil pressure.
At 2000rpm the engine has 60+PSI of oil pressure.
It max's out at 65/75 PSI at any RPM above 3,000.

Its running a 20W50 oil and has done 250,000km easy.
Do oil pressure figures like these suggest that the engine is running happily or does this sound high?

Thanks

i'M no expert but the pressure sounds OK to Me...

If the engine was worn, the pressure would drop...

LEE

68AutoBug wrote:i'M no expert but the pressure sounds OK to Me...

If the engine was worn, the pressure would drop...

LEE

I'm just abit surprised that even though it has over 250,000km on the engine it still has such a high oil pressure.
The repair manual states that the engine must have atleast 29PSI of oil pressure at 2,000rpm.
At 2000rpm though its pushing over 60PSI!

ryana89 wrote:I'm just abit surprised that even though it has over 250,000km on the engine it still has such a high oil pressure.
The repair manual states that the engine must have atleast 29PSI of oil pressure at 2,000rpm.
At 2000rpm though its pushing over 60PSI!

Well you are running 20W-50.

Probably Penrite too.

What is the recommended oil viscosity for your engine?

The tests you have done are meaningless with that thick oil, put the correct viscosity in and compare the results with the factory specifications, then you will have all the information you need to accurately make an informed decision.

I'd say, 250k.......mmm.....nicely run in, plenty of life left in that motor, my efi 2.1 Wbxr has 370k+ km on the odometer and it's still a factory engine....untouched.....change your oil regularly, use quality oil, and she'll get another 250k IMO.

Manual reccommends a 15W50 or 20W50 oil.
Its on Nulon 20W50 high K engine oil, but thats about to get changed over to Penrite soon.

Its getting 5000km oil and filter changes (about due in 400km). Changing the oil and filter every 5000km has been almost religious in my family, it always gets done.

Perfect, that's why it's as new 🙂

I'm not a big fan of Penrite, but plenty of people recommend it.

Hi Ryan, the pressure sounds too high (but is the gauge at all accurate?) - if you're saying it should be half what it actually is !!
It may be more harmful to have unnecessary high presure than slightly too low a pressure. High oil pressure readings can be produced by restricting flow (rate or volume), jamming pressure relief valves, over-cooling the engine, or using too thick an oil, etc. -- All potentially harmful things.
It may be a bit like high blood pressure -- no symptoms, but not good.
Instead of changing from one fairly thick oil (the Nulon one you mentioned is a slightly thicker "borderline" 20W-to-25W - 50) to another (HPR 30 for e.g. is thicker again, 25W-60), it might be worth trying one a 'notch' thinner, eg. a 15W-50, or 15W-40, or 20W-40.
Semisynthetics can be effective if engine operating over a wide temp range, eg Mobil 'S'; or, if you like Penrite, I think they now have some thinner semi-syn's for more modern engines.
You can quickly predict if the new oil will produce a lower or higher pressure, by looking at its specified visc. at 100C (= "normal" operating temp.), these should be all available on the web for most products.
eg. HPR 40: 29cSt, HPR 30: 23-24cSt, ACE 40: 20cSt, Nulon 'High km': 19cSt, ACE 30: 15cSt, Mobil S 10W-40: 14cSt, Mobil S 5W-30: 11cSt, ... etc.
This may be better than just considering the SAE spec's which are very wide...

Already 1 step ahead there Brutus😉
Should have mentioned what grade Penrite I'm going too😊
Im going down to HPR 15, which is 15W60 (extra 10) oil but thats just Penrites new BS campaign, when its really a 15W50 oil.

The 29PSI is an absolute minimum according to a manual that I have for the car, not so much a reccomendation.
I considered it may be a funky Pressure relief valve, but the pressure never goes past 65-75 (assuming this is the range the valve activates).

The previous owner ran the car on a 10W40 but that just seems really thin for such an old engine? (Lifters where a bit noisier too on the 10W40)
Wouldn't mind using Mobil 15W50 (perhaps 10W40) as they're one of the better oils, its just Penrite is a little more availiable.
The Nulon in it now is the Semi Syn 20W50, not the $15 rubbish in the black bottle.

Im relativly certain the gauge is accurate, its a new little 52mm VDO electric pressure gauge.
Thanks!