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Does a large spike in oil pressure matter?

My 1985 Jeep Wrangle recently over heated. After filling up the radiator everything works great.

Except I’ve noticed now that the oil pressure has gone from 40 to 80.

I went to oil changers and had them change the oil and the oil filters. But the gauge still shows the oil pressure at 80.

Is this something I need to worry about? If so what might be the problem?

It was only overheating because you were low on coolant? That means that the Jeep was probably running very very hot but not quite overheating for a long time while the coolant was somewhat low (but not low enough). It is very normal on an older engine for the oil pressure to be a lot lower when the engine is hot-- I’ll bet that the reason why it’s higher now is that the engine is running cooler.

Another possibility could be that the overheating damaged the pressure sender. Does the gauge read zero when the engine is off and change with engine speed at all?

The gauge does read zero when the engine is off. It gradually gets to between 70 and 80 after a little driving. All other gauges are normal and the car performs as expected.

It sounds like I should replace the pressure sender and see it that fixes the problem.

Yes it overheated because I let the coolant get low. After letting the car cool I filled the coolant and it’s been running great since then. (other then the oil pressure)

Yeah, that sounds like the oil pressure is just higher because the engine is running cooler now.

This begs the question though, where did the coolant go? It shouldn’t just disappear-- if it was low it either had to have leaked out or burnt through a head gasket leak.

I had both my Wranglers go low on coolant with no apparent leaks and holding good pressure. I finally traced it to the rad caps in both (oddly, they happened within about a month of one another).

As was suggested, I’d swap out the sender or tap a mechanical gauge.

On a very cold morning 10 degrees. While on the interstate the jeep overheated. Lots of steam shot out of the radiator reservoir. After the jeep cooled I added 1 1/2 gallons of antifreeze and the jeep started right up.

Even though it started I had the jeep towed home. The driver said I had too much water and not enough antifreeze.

At this time none of the coolant system leaks and the jeep runs at a normal radiator temperature. I’ve had the coolant system flushed and refilled at oil changers. The fluid level is holding constant and the coolant temperature gauge is reading normally.

80 would be pretty high for this engine, regardless of whether you have a 6 or 8 cylinder, especially if it stays at 80 when the engine is warm. Have a mechanical gauge put on it to see if the pressure the dash gauge is indicating is accurate before considering anything else.


Thanks for the information. I’ll take it into the shop and have it tested.

My jeep is 4 cylinder and the pressure moves between 70 and 80. But for the most part once the jeep has warmed up and is driving the pressure reads 80ish.