Erratic oil pressure

[SevensOdd]

hey lately my oil pressure has been jumping around quite a bit. ill start the car, warm it up, and the oil pressure will be excellent....ill drive for maybe 3 minutes and the needle will be right on L. 5 minutes later then needle will slowly creep up.....never getting past that first notch. Then maybe 10 minutes later it will be excellent again. And so on and so forth. any ideas as to what may be causing this? thank you

 

[GSX93DSM]

Stock gauge or aftermarket. It could be the oil sending unit if it is a stock gauge. I never trust those. Get an aftermrket and then try it. If you already have an aftermarket it might have air in it, unlossen it and get the air out then try it.

 

[NickGT20]

Actually the stock gauge with a GOOD sending unit is proven to be very accurate. One of the few guages on a DSM worth trusting. Your oil pressure at start up should be high and then once the car is warmed up the pressure should be rather low at idle and basically increase due to rpm. I forget whether or not the dsm's run a centrifical pump but I believe they due. With centrifical pumps the pressure always increases due to rpm unless you have bad seals, rings, etc. The safest thing for you to do would be to buy a known good guage like a test set and check a manaul for the range at idle and running. It can be very erratic for instance my mustang runs about 22 psi of oil pressure at idle and I usually pin my guage at over 100psi going through the traps. The type and weight of the oil can also affect your readings. Thicker viscoitiy oil will be less likely to leak through warn rings etc and you'll see more pressure.

Just get a known good guage to be safe and check your chiltons or hayes manual for the pressure.

 

[Defiant]

The connector on your sender is tired.