oil pressure 4 bar without engine running?

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cschmueck
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oil pressure 4 bar without engine running?

Post by cschmueck »

Hi all,
first run of the year. My oul pressure shows 4 bar with ignition on, engine not yet started. After starting the engine, the oil pressure maxes out with an audible click for the first 3 or 4 minutes.
Has anyone on here had something similar?
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Re: oil pressure 4 bar without engine running?

Post by SeanP »

Check your engine ground strap
Pull the wire off of the sender. What does the gauge do? Short the wire to the engine block. What does the gauge do.
If the engine ground strap is ok then replace the sender
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cschmueck
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Re: oil pressure 4 bar without engine running?

Post by cschmueck »

Thanks.
engine ground is fine, measured that, also on the sender unit body. Earth on the gauge also without issue.. I kind of get the feeling that it has something to do with the pressure relief valve in the engine... all replaced at the time I went over the mechanical bits of the car...
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Re: oil pressure 4 bar without engine running?

Post by neilbardsley »

cschmueck wrote:Thanks.
engine ground is fine, measured that, also on the sender unit body. Earth on the gauge also without issue.. I kind of get the feeling that it has something to do with the pressure relief valve in the engine... all replaced at the time I went over the mechanical bits of the car...
Sometimes this can mean the sensor is not connected? If this isn't the problem is there a way to earth the wire connected to the sensor and see if the gauge returns to zero?

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Re: oil pressure 4 bar without engine running?

Post by KS »

cschmueck wrote: Sun Jun 21, 2026 4:32 pm I kind of get the feeling that it has something to do with the pressure relief valve in the engine... all replaced at the time I went over the mechanical bits of the car...
It can't be anything to do with oil pressure relief valve if the engine isn't running, or hasn't already been started. There is no pressure without the oil pump pumping oil round the system. If not a basic wiring fault, then sounds to me you might have a mismatched sender and gauge.
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Re: oil pressure 4 bar without engine running?

Post by PeterK »

With the sensor disconnected you should have max oil pressure on the gauge and with the cable to the sensor earthed to the engine you should have zero pressure indicated

My guesses are that most likely you have a dirty connection to the sensor but could be a failed sensor
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