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Oil Pump Problem?

Hello Everyone,

I have a 1994 Chrysler Lebaron. The issue I’ve been having is for the last two weeks, my oil pressure gauge starts very high(out of normal range), and stays there for a very long time. Whilst it’s at the highest possible level, the engine starts to heat up, until the gauge goes into range. This all happens without the car moving. If I leave the car on for 30 minutes(without moving it) the gauge goes into normal range, and for the most part operates normally. I have disconnected the Compressor’s belt, in order to be able to turn on the engine fan from inside the car. As long as I keep the fan on, the engine stays cool for the most part.

I have considered that it was sludge, as it would soften as the engine heats up, but I have done an engine flush(machine), and the issue continues.

So far every mechanic I take it too, acts like it’s impossible for the oil pump to have any issues, and claims it’s normal behavior, which it’s not.

Had a mechanic checked the oil pressure with a different gauge? Same for the high temperature? Sounds more like an electrical problem with the gauges.

How many miles do you have on the car & what engine do you have.

@Texasas; is right and it is a simple check for a mechanic to put an oil pressure gauge and Temp gauge on the engine to chech that yopur gauges are accurate.


@Texasas I have not had them checked it because none so far think a problem exist. To do my own testing I turned the car off when the temp gauge reported a high temp, and anti freeze began pouring out confirming the temp. Also the pressure sensor is new as of two months ago.

@Yosemite 204,016 / Mitsubishi 6G72 3.0 L

With that many miles it could be many things that are causing the problem.
Though the pressure sensor was replaced, the gauge may still be faulty.

Go back and insist that they hook up a temporary gauge to it.
Or if you feel capable…go get a gauge cluster with Temp and Pressure gauges…and either mount them below the dash, or just install them temporarly under the hood.


I am at a mechanic, who claims to once own one. He believes it’s the head gasket. Would these symptoms correlate with a head gasket issue?

It’s possible that the oil pressure relief valve is stuck closed, causing excessive oil pressure.

You could try removing the relief valve spring and plunger from the bottom of the oil pump to see if the plunger was stuck closed.

It’s normal for idle oil pressure to drop some when the oil gets hot.
I’m almost certain it’s just the gauge, range is way off.
I’ve never heard of and can’t imagine an engine with too much oil pressure at idle.
The relief valve could be stuck closed and you’d still have normal pressure at idle.
Then the problem would show at higher engine speeds.

The engine for the past two weeks takes longer to start. It started with a pause during cranking, now it just takes a little longer to start.

I tried clearing the injectors, but that would not explain the cranking pause.

Maybe you are focusing on the wrong “problem.” It sounds like there’s a problem with the cooling system if you have to run the fan manually. Has the engine ever overheated? If your mechanic says he thinks it has bad head gasket, that suggests he sees an issue with overheating. And these engines are prone to head gasket failures. So I’d be more worried about fixing that than worrying about oil pressure.

They started work on the Head Gasket yesterday (07/31/2014). I will keep you guys update, Thanks for the assistance.