High oil pressure reading

buick
lesabre

#1

My '02 Buick LeSabre suddenly went from normal oil pressure to a very high 130 psi. No warning codes or lights.
This car has the DIC readout. is the problem the sending unit? There is no analog gauge and the oil warning light seems to be normal. (goes out on startup)
Using 10W30 oil Changed filter as well. No difference.


#2

That’s extremely high and a good chance to damage your engine if accurate. I believe the oil pressure relief valve is stuck. The other cause could be a bad sending unit. I would have it looked at right away. The sending unit is quickly and easy to replace.

Bye the way, does it say normal next to the readout?


#3

Disconnect sending unit and see if gauge goes to zero. Sender is on timing cover above oil filter. If it does, sender’s most likely bad. Have seen a few of these Buick 3800s blow a few oil filters off when pressure relief valve stuck. That was on the earlier generations of 3800s though. If high oil pressure is the case, the timing cover will need to be replaced as the pressure relief valve is in the timing cover.


#4

Thanks! I will do that. Do you know if there is a port in the engine that will accept an analog gauge for testing purposes?


#5

Thanks for the input. And, yes, the DIC says normal.
I’m guessing that the sending unit is more accessible if the oil filter is out of the way. I don’t have a car hoist. So will be using jack stands to get to the unit.


#6

You’ll have to get a special socket to remove oil sender. Then you screw oil pressure tester into port. Shouldn’t have to remove filter. Oil pressure with engine up to temp at 2000 RPM should be at 60 PSI minimum. If it’s way high, i would suspect oil pressure relief valve.


#7

If the display says “normal” it is the sending unit that is bad.

Edit: No hoist needed. Jack stands are just fine. You can reach the sending unit without removing the oil filter. May bump your head and scratch your hands a little here and there, but it’s not too bad. An open ended wrench will work fine to get this thing out. Don’ forget to unplug the unit first.


#8

It’s most likely the sending unit. I changed mine during an oil change. Much easier with the filter out. It was a couple years ago that I changed mine, but I don’t recall needing a special socket.


#9

The timing cover doesn’t require removal in order to replace the oil pressure relief valve.

Just remove the oil filter adapter to replace the valve.

Tester


#10

Fantastic! Thanks.


#11

Thanks. I don’t think it’s the valve anyway. Pretty sure it’s the sending unit judging from all the other helpful replies.


#12

If the pressure relief valve hangs up in the timing cover it’s due to timing cover being scored. Valve is steel, timing cover is aluminum which means timing cover replacement in a case such as that. It is quite rare, though. I believe it’s been about ten years since I had to replace a cover for this problem.


#13

Timing cover is not damaged. Thanks for the input though.
As the DIC reads out normal even thought he pressure reads high, I am convinced it’s the sending unit.
Thanks.