Intermittent low oil pressure

[scot850]

Both you guys have great ideas. I had been thinking about the oil viscosity too. I run my 2000 V70R with 5W40 oil, but the other engines I used 10W30 all year around once the mileage went up higher. Found oil loss dropped significantly.

My buddy just made it back from a 7400km trip at mostly 60-70 mph and occasionally higher. Car has about 190,000 miles on it. It is running 10W30 and he used about 3/16" of oil with the car overloaded. Non-turbo V70 with 210kg over max on board and fully loaded roof rack too.

Neil.

[Shiruba]

What oil viscosity you have in the engine?
What oil filter you installed?

If oil is too thin for the mileage and condition of the engine...oil pressure will not be adequate.

If oil filter is something aftermarket without built-in check valve....oil pressure will be compromised.

It had 5-30 in it I switched to 10-30 just yesterday and it's a genuine Volvo filter

[Shiruba]

Good points by misha.

Is there any evidence on the dipstick of foaming/aeration in the oil after a long drive? Would point to an issue with the seals.

No, no foaming or anything of the sort

[misha]

5w-30 and 10w-30 is too thin for the car with that mileage.
5w-40 or 10w-40 would be more adequate.

Both of those oils have the same viscosity when engine is at operating temperature(xx-30 index).

You might have a problem with oil pressure...but there is a possibility that the light is shorting somewhere.

[Shiruba]

5w-30 and 10w-30 is too thin for the car with that mileage.
5w-40 or 10w-40 would be more adequate.

Both of those oils have the same viscosity when engine is at operating temperature(xx-30 index).

You might have a problem with oil pressure...but there is a possibility that the light is shorting somewhere.

Alright I'll try it with 5w-40 I checked the wire and cleaned the plug, it was dirty and I think I need to redo the valve cover gasket as well with how grimy it was. I haven't started it yet since then since I'm waiting on some tie rods and a cv axle so it's still jacked up.

[misha]

I'm not claiming that higher viscosity oil would solve your problem,but there is possibility.

You should be able to test oil pressure before throwing money again on something you just replaced.
There is some gauge which is screwed into the pressure sensor hole while engine is running.
That would clear the mistery if it's a false warning or you really have a problem with oil pressure.

[scot850]

+1 with misha on the oil pressure reading if it continues after the oil change.

If you continue to get oil film on the top of the engine on the cover and around cylinder #2 and #3, change the oil filler cap ring and make sure when it fits it is tight. Also check the PCV pipe that runs by the oil filler hole from the PCV trap. They can split with age or I have had them come off their seat and vent into that area.

I wish you luck!

Neil.

[Shiruba]

I'm not claiming that higher viscosity oil would solve your problem,but there is possibility.

You should be able to test oil pressure before throwing money again on something you just replaced.
There is some gauge which is screwed into the pressure sensor hole while engine is running.
That would clear the mistery if it's a false warning or you really have a problem with oil pressure.

I have connected a pressure gauge and it seemed to stop dropping around 50psi when it was warmed after reaching 3000 rpms then returning to idle it dropped to around 40psi but didn't drop further. The low oil warning was never consistant seemed to be rather difficult to place exactly when it would flicker on. I have also replaced the full pcv breather system

[misha]

I don't know what is the spec for oil pressure...but i think that sensor is faulty here.

I would replace it anyway.

Read this:
https://www.pelicanparts.com/techarticl ... cement.htm

[Shiruba]

I don't know what is the spec for oil pressure...but i think that sensor is faulty here.

I would replace it anyway.

Read this:
https://www.pelicanparts.com/techarticl ... cement.htm

I did replace it with a genuine Volvo replacement. However the light still have a brief flicker after being allowed to run for a little while