Volvo MD2020 - Dipstick oil level

[Jokani]

My oil pressure gauge is showing low, below 1 bar @ 1600rpm, but when I check with the dipstick fully inserted the level is way over the max mark, and I'm not sure how that can happen. I have tripled checked the dipstick level, once when the engine hadn't run for more than 12 hours.

I'm pretty sure when I last checked the oil level I fully inserted it (which is correct?) and the level was almost to the full mark, but maybe memory and old age are playing tricks on me.

To confuse me further, if I just rest it on the rubber bung (rather than fully inserting), then the level is below the minimum, which would match the gauge.

So I am not sure if it is:

1) That I have a problem that is causing the dipstick oil level to higher than than it is

or

2) Everything is OK, the dipstick should just rest on the top, is does need topping up and the gauge is correct

or

3) Something else entirely.

Any advice much appreciated.

 

[pvb]

The oil pressure gauge doesn't tell you anything about the oil level in the sump!

I'd suggest measuring the oil level with the dipstick fully inserted. Make sure it's correct. If it's too high, run the engine some more and see whether the oil level increases further - if so there's a problem (probably fuel getting in to the sump).

 

[RichardS]

The oil pressure gauge doesn't tell you anything about the oil level in the sump!

+1

If the oil pressure is much lower than it used to be (and 14 psi does not sound great) and the oil level is showing on the dipstick (rather than being catastrophically low) then it sounds like your oil pump is failing or the main bearings could be on their way out.

However, if everything seems OK and there is no knocking, I would suspect the sender or gauge and check those first as oil pump/bearing failures are very unusual in a well-maintained engine.

Richard

 

[NorthUp]

If the oil level on the dipstick is rising, your oil is probably contaminated with diesel- lowering its viscosity and hence the oil pressure. You may be able to smell diesel on the dipstick.
Possible sources are a leaking lift pump, which should have a tell-tale hole on the mounting flange, faulty injection pump, or a faulty fuel injector.
edit- assuming the oil has not turned grey or creamy white, which would be water contamination

 

[RichardS]

If the oil level on the dipstick is rising, your oil is probably contaminated with diesel- lowering its viscosity and hence the oil pressure. You may be able to smell diesel on the dipstick.
Possible sources are a leaking lift pump, which should have a tell-tale hole on the mounting flange, faulty injection pump, or a faulty fuel injector.
edit- assuming the oil has not turned grey or creamy white, which would be water contamination

Interesting. I had not understood the OP to mean that the oil level is actually rising but thought it was because the dipstick is not being inserted properly .... so, looking at it again, if, with the dipstick fully inserted, the oil level is actually going up, then it's not oil pump or bearing failure which did seem unlikely, but must be oil contamination and NorthUp has described that above.

Richard

 

[VicS]

If the oil level on the dipstick is rising, your oil is probably contaminated with diesel- lowering its viscosity and hence the oil pressure. You may be able to smell diesel on the dipstick.
Possible sources are a leaking lift pump, which should have a tell-tale hole on the mounting flange, faulty injection pump, or a faulty fuel injector.
edit- assuming the oil has not turned grey or creamy white, which would be water contamination

If there was a tell tale hole wouldn't engine oil leak from it?

 

[NorthUp]

If there was a tell tale hole wouldn't engine oil leak from it?

possibly.. I was thinking Amel lift pumps on Gardners, not Perkins/ Volvo/ Japanese engines!

 

[Heckler]

My oil pressure gauge is showing low, below 1 bar @ 1600rpm, but when I check with the dipstick fully inserted the level is way over the max mark, and I'm not sure how that can happen. I have tripled checked the dipstick level, once when the engine hadn't run for more than 12 hours.

I'm pretty sure when I last checked the oil level I fully inserted it (which is correct?) and the level was almost to the full mark, but maybe memory and old age are playing tricks on me.

To confuse me further, if I just rest it on the rubber bung (rather than fully inserting), then the level is below the minimum, which would match the gauge.

So I am not sure if it is:

1) That I have a problem that is causing the dipstick oil level to higher than than it is

or

2) Everything is OK, the dipstick should just rest on the top, is does need topping up and the gauge is correct

or

3) Something else entirely.

Any advice much appreciated.

Looks like the diaphragm has gone letting diesel in to the sump, thinning the oil and the pressure goes down and the level goes up. Go here for a new pump, https://www.parts4engines.com/volvo-penta-md2020-fuel-lift-pump-kit/

 

[Heckler]

possibly.. I was thinking Amel lift pumps on Gardners, not Perkins/ Volvo/ Japanese engines!

If Ive done it right here is a diag of the pump, if the diaphragm lets go diesel can get in to the sump
https://www.marinepartseurope.com/en/volvo-penta-explodedview-7746800-23-171.aspx

 

[Jokani]

Thanks for all the advice, I fiited a new lift pump (from parts4engines) during a re-build less than 75 hours ago, so I wouldn't have though that would have been the problem

I'll take another this weekend and see if I can see any evidence of diesel in the oil, but that does sound like the logical explanation.

Life is never simple is it!

 

[Heckler]

Thanks for all the advice, I fiited a new lift pump (from parts4engines) during a re-build less than 75 hours ago, so I wouldn't have though that would have been the problem

I'll take another this weekend and see if I can see any evidence of diesel in the oil, but that does sound like the logical explanation.

Life is never simple is it!

No! definitely not simple. It could also be an injector not spraying properly but that is a faint possibility. You should have noticed the misfire. The diaphragm perforated on the lift pump gives those classic symptoms, even though its fairly new I would check it.

 

[Jokani]

Possible sources are a leaking lift pump

Looks like the diaphragm has gone letting diesel in to the sump

I emptied and refilled the oil, ran for a few hours and the problem seemed to have gone away.

But, when started the engine did not want to rev for approx 30 seconds. I was told (thanks Paul) that this could be due to an air leak somewhere in the system.

As both problems could have been caused by a faulty lift pump, I replaced it. I have run the engine for 10 plus hours over the last few weekends, and so far no reccurence of either problem.

Thanks for all the advice, particularly NorthUp, skipper_stu and PaulRainbow

 

[Heckler]

I emptied and refilled the oil, ran for a few hours and the problem seemed to have gone away.

But, when started the engine did not want to rev for approx 30 seconds. I was told (thanks Paul) that this could be due to an air leak somewhere in the system.

As both problems could have been caused by a faulty lift pump, I replaced it. I have run the engine for 10 plus hours over the last few weekends, and so far no reccurence of either problem.

Thanks for all the advice, particularly NorthUp, skipper_stu and PaulRainbow

Excellent! One thing I did learn many years ago was even though a new part was fitted, if the symptoms said it wasnt working then it wasnt working. Just the way the cooky crumbles sometimes. Just sitting in the cockpit in Albufeira at the mo, feelng v mellow after a hot day!

 

[jiris]

I am a bit confused with your findings, but just to make sure you are drawing the right conclusions:
The pressure you gauge is showing has nothing to do with the oil level in the sump. It will remains the same to the point, where the suction pipe is getting intermittently exposed to air. Then the pressure will not drop, but it will become fluctuating wildly before it gets permanently to zero. The reading on the dipstick can get confusing, when the rubber seal on the top is really tight. If you pull out the dipstick after the engine has been running for a while, it may show a very low level - simply because the air in the tube expanded and displaced the oil in it out. You have to reinsert the stick (fully down) and take the reading again. This will be the right one . But, it seems like you are experiencing the opposite (if I understand correctly) and in that case I have no explanation ;-(.