oil pressure guage problem

[77crewcab]

I am having an issue with my oil pressure guage on my 90 burb. I swapped the engine from a parts burb with a bad trans. When running before the swap the oil pressure read about 45-60 psi. Now with the engine in the new burb the guage pegs at 80 psi. I haven't done anything yet but will probably change out the guage just because it is easier than the oil pressure sender. But anyone have any advice about how to diagnose the issue other than just swapping parts?

 

[dyeager535]

If all you did was swap the engine, its not likely at all that the gauge is the problem.

I'd bet the wire got screwed up on the install, and that's where the problem is. Disconnect the sender with key on/engine off, see if gauge position maxes one way or the other. Now ground the sender wire, should max the other direction. If it does, then the sender is faulty. If it doesn't, the gauge or wiring is faulty.

Very unlikely the gauge coincidentally decided to fail when you swapped motors. The gauges are extremely robust, and fail much, much, much less often than the senders.

 

[77crewcab]

Actually the burb I swapped the engine into had sat for several years after the engine blew up. I have no idea about the condition of the guage in it or if it worked before hand. Right now it is off getting the trans rebuilt. Once I get it back I plan to start trying to work on the oil pressure problem and will try what you suggested. Thanks.

 

[4X4HIGH]

I had the same thing happen when i swapped my engine (except i dropped the sender) and it ruined the sender. Is yours a 3 wire sender? I can almost guarantee the sender is the culprit as the gauges rarely go bad. The 3 wire sender works the gauge and is also the fuel pump back up.

 

[77crewcab]

I had the same thing happen when i swapped my engine (except i dropped the sender) and it ruined the sender. Is yours a 3 wire sender? I can almost guarantee the sender is the culprit as the gauges rarely go bad. The 3 wire sender works the gauge and is also the fuel pump back up.

Yeah it is the 3 wire sender. I have a couple extras I can try when I get the truck back. They are just such a pain to get to I was hoping it would be just the guage.

 

[4X4HIGH]

Yeah it is the 3 wire sender. I have a couple extras I can try when I get the truck back. They are just such a pain to get to I was hoping it would be just the guage.

Pull the distributor, it is easy then. I just like to turn the engine over until the rotor points straight forward towards the bumper then pull the dizzy install the sender then drop the dizzy back in and re-time the engine. Quick and easy this way.