High Oil Pressure Problem?

[simsk 1]

Hello all,

 

Got a funny problem atm, I am hoping it might just be the sensor or gauge but can't afford a mechanical gauge atm. Interested to hear your thoughts?

 

The oil pressure after a long trip 200miles motorway miles has risen in a pretty linear fashion. It used to run like normal to the second from top marker when accelerating and drop to the first marker (2bar?) on idle but now it will run on the top marker (8bar?) on accelartion and only drop to the 3rd marker after its warmed up? for the first 20mins of driving though it'll always stay right near the top of the gauge...

 

I have only just service the car (bad on my behalf as should have done it when I bought the car but i've only done about a 1000miles in it so was on the to do list) and the oil was pretty black and horrible. Replaced the filter with an original peugeot part and plan to do this a few times until I get some clean oil through but now I have this problem and have put that on hold until I can drive the car again.

I've checked the oil breathers (crankcase and overfill) both are clear...

 

Anyone got any ideas? had similar problems? worse thing im thinking is an oilway in the block is clogged up? took the sensor off and it looked ok but it does come off a T piece from the block and haven't removed that yet to make sure that's clear to the block... just thought of that.

 

any help/suggestions appreciated

[jackherer 543]

What grade of oil did you fill it with?

[simsk 1]

I just used some cheap 10w40 that I was using a flush.. didnt think about that though...

[camgti 56]

Sounds like the fresh oil is just getting proper pressure?

[simsk 1]

didn't think about this but the oil change was after the oil pressure problem hence what made me do it. So unlikely to be problem \i think. Going to see if anyone I know has mechanical oil pressure gauge I can borrow tomorrow.

[dcc 855]

The gauge is a guessometer at best, to get a true representation of oil pressure you need to get a mechanical gauge fitted. The standard gauge runs on resistance - i guess your wiring is 30 years old now so not exactly reputable

[jackherer 543]

You're right that the wiring is old and rubbish generally but in this case a maximum reading requires a perfect connection to ground so any resistance or bad connections will cause a low reading. The only way the wiring can make the gauge read high is if it gets caught somewhere and shorts to ground.