Oil Pressure Readings

[Gypsie]

What should one expect to see in oil pressure? Cold? Hot? Low rpms (under 2000). High rpms?
(type 4 2L FI, New guts)
I have installed a gauge and am unsure what is good too see and what may be concerning.

[Amskeptic]

What should one expect to see in oil pressure? Cold? Hot? Low rpms (under 2000). High rpms?
(type 4 2L FI, New guts)
I have installed a gauge and am unsure what is good too see and what may be concerning.

Start-up oil pressure normally shoots up to 40-60 on a cold morning. As the engine warms, oil pressure will drop to 10 at idle and 40 underway.
Hot oil pressure at idle can drop to 5-10 and barely hit 30 underway. With a fresh engine, readings will often be higher. A sort-of-rule-of-thumb is about 10 psi per 1,000 rpms.

Type 4 engines have serious good bearing support, they can idle on insanely low flickering light oil pressure, but you want pressure/flow once under load.
Colin

[Gypsie]

Whew....I was gettin worried when it was dropping down so low during idle.

Thanks.

[Hippie]

FWIW, with hot 10W-40, mine reads barely off the zero peg at idle and makes about 24 psi at 70 mph true speed if the outdoor ambient is even only 50-60 degrees.

[Amskeptic]

FWIW, with hot 10W-40, mine reads barely off the zero peg at idle and makes about 24 psi at 70 mph true speed if the outdoor ambient is even only 50-60 degrees.

Do you trust your gauge? That is below comfort zone.
Colin

[Hippie]

I know the gauge is true, but 20W-50 blew me up a filter...so I ain't ready to change to that yet...still cold in the AM.
Probably my whole engine is a loose bag of poop anyway.

[chitwnvw]

FWIW, with hot 10W-40, mine reads barely off the zero peg at idle and makes about 24 psi at 70 mph true speed if the outdoor ambient is even only 50-60 degrees.

I've seen that with DD gauges.

[Hippie]

I've seen that with DD gauges.

Well there you go then. I check my mechanical OP gauges against some knowns (like my HVAC manifold gauge set which is calibrated) with an adaptor I made for my air compressor regulator, so they should be pretty close to accurate.
Actually, I have seen only pretty good accuracy and agreement out of the box with these auto-parts-store mechanical gauges, of which I have several.

[Amskeptic]

I've seen that with DD gauges.

Well there you go then. I check my mechanical OP gauges against some knowns (like my HVAC manifold gauge set which is calibrated) with an adaptor I made for my air compressor regulator, so they should be pretty close to accurate.
Actually, I have seen only pretty good accuracy and agreement out of the box with these auto-parts-store mechanical gauges, of which I have several.

A VW is easy on the bearings at idle compared to other engines because it has so much surface area devoted to very little action. But the opposite is true on the highway, where a VW is asked to perform way up the rpm scale in a hot environment and that welcome surface area is now also a friction field. Get your viscosity up and let us know your highway pressure.
Colin

[Hippie]

A VW is easy on the bearings at idle compared to other engines because it has so much surface area devoted to very little action. But the opposite is true on the highway, where a VW is asked to perform way up the rpm scale in a hot environment and that welcome surface area is now also a friction field. Get your viscosity up and let us know your highway pressure.
Colin

Sound reasonable.
Interesting.
OK, I will bump back up to my "summer weight" Castrol 20W-50 as soon as I can, and report the latest.
We are having an abnormally cold week and it is only 27 degrees outside as I write.