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dieseldan55
dieseldan55, Mechanic
Category: Construction and Road Equipment
Satisfied Customers: 744
Experience:  Road Mechanic for Volvo Construction Equipment.
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Volvo l90e intermittent low oil pressure message on. Engine

Customer Question

Volvo l90e intermittent low oil pressure message on. Engine lacks power when on. I have replaced oil pressure sensor
Submitted: 1 year ago.
Category: Construction and Road Equipment
Expert:  Dan replied 1 year ago.

Hi my name is***** will be glad to help. The ECU is derating the engine resulting from the active fault and it will continue to do this until the problem is fixed. Check and verify the actual oil pressure is within specs ans if so check the sensor harness for problems since the sensor is new. Let me know if you have any fault code numbers and your serial number of your machine if you need more help

Expert:  dieseldan55 replied 1 year ago.

Hi This Is dieseldan55, In addition to what the other expert stated, a common failure point is the pressure relief valve mounted behind the oil cooler. If yours hasn't been changed yet indicated by still being green paint on the cooler base. Then i would highly recommend changing the oil cooler and base unit with the relief valve. A relativity easy job and if you need more details please ask for me. Thanks.

Customer: replied 1 year ago.
The oil cooler base is green. Where exactly is the pressure relief valve located?
Expert:  dieseldan55 replied 1 year ago.

In behind the base, you will need to drain the coolant and remove the oil cooler and then the base to access the relief on the back side. Its a small check valve with a spring that will break or the check valve will become loose or unsecured in the mountings. I would advise to do a manual pressure reading first and that will ensure your on the right path. I can see if I can get a picture sent your way if you like.

Customer: replied 1 year ago.
What is normal oil pressure supposed to be at?
Customer: replied 1 year ago.
Is the relief valve serviceable separately?
Expert:  dieseldan55 replied 1 year ago.

Oil pressure on a warm engine at high idle is 60-70 psi. Here is a picture of the relief, item #2.

Expert:  dieseldan55 replied 1 year ago.

It does offer a part number, however I have always change the unit out. I would recommend changing the unit out, because the earlier versions had a different housing and if you bought the one part it might not accept the piece.

Expert:  dieseldan55 replied 1 year ago.

I highlighted the gaskets needed, since you will need to remove item 24 as well to slide the pieces out.

Expert:  dieseldan55 replied 1 year ago.

I forgot to check off item 1, up to you on oil cooler replacement. I have done a bunch of those as well since a few have failed.

Customer: replied 1 year ago.
Oil pressure is at 32psi intermittently when warm
Customer: replied 1 year ago.
Why does number 1 and 22 say their the same thing?
Expert:  dieseldan55 replied 1 year ago.

Okay then it would be worth inspecting the relief. The nomenclature is a Volvo brilliance in part description. Just use the picture to get the correct part number.

Expert:  dieseldan55 replied 1 year ago.

Hello, following up to see what your found and to make sure i satisfied your question.

Customer: replied 1 year ago.
I ordered parts. I'll let you know when I install them.
Expert:  dieseldan55 replied 1 year ago.

okay great thank you.