3.0L Gl-J Oil Pressure

Hello All,

I have a 3.0L GL-J (2009) with 26 hours.

The engine runs fine after I fixed a fuel line issue.

My question is:

Does anyone else see a fluctuation of oil pressure at idle speeds? Mine bounces from 15-30-erratic. It holds firm at anything over idle speed?

The oil has been changed twice using Volvo Oil and Volvo filters (835440). OEM only for me.

Engine end and guage end connections appear good/tight.

It looks like there are two senders on this engine. Both on a tee fitting. I am assuming one is for the guage and the other for the warning buzzer.

Faria Guage.

Thoughts?

Re: 3.0L Gl-J Oil Pressure

You could put a mechanical gauge on the engine to see if its the engine or if its the sender/gauge.

Re: 3.0L Gl-J Oil Pressure

Agree, that's my next step. Just curious if anyone had seen this issue. I just didn't want to break that Pretty red paint.

For what it is worth, I had a 1980 Jeep with a 2.5L "Iron Duke" engine. This engine is SO similar, yet SO different.

By looks, it looks the same, other than the head. The 2.5 had a crossflow head, the 3.0 has an L Head (exhaust/intake-same side). Once you get deeper into it, the differences become clear. Both were/are ancient technology, especially the 3.0L for a so called modern engine.

I see that Volvo Penta dropped the 3.0L for anything forward and MerCruiser EFI's it with a marine Cat. convertor.

Obviously MerCruiser believes in it.

Some very experienced I/O folks tell me it's a good engine but maintenance is critical. No problem there.

Re: 3.0L Gl-J Oil Pressure

I would suspect a bad sender , like someone else suggested put a mechanical guage in and test it.

Re: 3.0L Gl-J Oil Pressure

Thanks all, doing that tomorrow.

Re: 3.0L Gl-J Oil Pressure

These are just thoughts...........but mine is the same way.

First though--what is your idle RPM? 550? 600? More?

I have a 3.0 10 years older than yours....1999. The oil pressure gauge does jump around a bit at idle (don't know if it goes down to 15, but it is definitely jumpy at anything under about 1000 RPM.)

Your gauge should have an area (amber/yellow/red?) that indicates low pressure, and you should also perhaps have the low pressure buzzer to augment that condition. If your needle is entirely within the "low" range at idle, you may have an issue. If it only barely dips into the "low" area during fluctuation, then that's the response of the sender/gauge.

I won't go so far as to say this is definitively "normal", but with only a four-cylinder throwing oil around at a relatively low RPM, the gauge is probably not getting enough stable input to give a "hard" indication, and is therefore "erratic", and the needle compensates (or over-compensates) accordingly. That is, until you give it some gas, and get the RPM's up enough to where oil flow is stabilizing.

I believe, somewhere (wish Don was here....) that there is a chart of oil PSI vs RPM on the 3.0....might try searching for that too...

But in the end, my own personal opinion would be that you're OK. Let us know what the mech' gauge does.

Re: 3.0L Gl-J Oil Pressure

Just an addendum:
We went out last night.
After full warmup and short run, I throttled down to idle.
My oil pressure was jumping anywhere between 20 to 28, so about 24, and just over 40 at 3200 RPM. (I don't run around at max RPM of 4600 much....but I want to say it was around 46 or so last week after I tweaked my carb and took her for a run....).

My gauge is not very accurate; it only has 20 psi increments and a yellow low band that looks to be around 15psi and below.

Re: 3.0L Gl-J Oil Pressure

double post....ooops

Re: 3.0L Gl-J Oil Pressure

insttech1 said:

Just an addendum:
We went out last night.
After full warmup and short run, I throttled down to idle.
My oil pressure was jumping anywhere between 20 to 28, so about 24, and just over 40 at 3200 RPM. (I don't run around at max RPM of 4600 much....but I want to say it was around 46 or so last week after I tweaked my carb and took her for a run....).

My gauge is not very accurate; it only has 20 psi increments and a yellow low band that looks to be around 15psi and below.

Click to expand...

Thanks. Mine is similar.

My guage (Faria) is a bit different. It just has PSI readings, no good, bad, ugly bands.

I have found the engine actual oil pressure is steady. Verified with a mechanical guage. So, I now know it's the sender or guage. Now that I know that, I'm good.