high oil pressure

[kjegbert23]

I'm not sure if I really want to know the answer to this. When I start my 91 yj 2.5L it is at just over 40 lbs for oil pressure. As I start driving it the gauge goes up to between 65 and 75 lbs and stays there until I let off the gas to shift gears. Then it drops to about 40 and starts to climb again as the RPM's go back up. I've already replaced the oil pressure sending unit. Oil level is right on and I will be doing an oil change this weekend. Any other ideas?

 

[volaredon]

maybe your oil pressure really is that good? Could be a defective new sending unit, would not be the 1st time; check it with a manual gauge (even a dash mount Stewart Warner/Sunpro type) to verify the reading. but low oil pressure typically is a more common problem than being "too high". but I have heard of the pressure relief valve sticking within the oil pump. if it stays between 65-75, is accurate at that level, and don't shoot up much more than that, I think I'd be real happy with it!
what weight oil do you run? That will affect pressure.
also if this happened "all of a sudden", where your actual oil pressure may not really be that good, then it could be a bad ground bad gauge etc. Bcak to verifying the pressure with a manual gauge.

 

[Sine Deviance]

If you're positive it's not the sender then I would recommend the oil change as the next step. Before I did my last oil change I was constantly pegging the gauge as far as it could go. After the change it now sits around the 40 range like it should.

Sometimes the filters get a little clogged up. It can even happen if you just changed it recently.

Keep in mind that if you actually do have oil pressure that high it's not good for your seals. Get it back to normal asap.

 

[kjegbert23]

I run 10w30 oil. It never has seemed to get that high in the past. I replaced the sending unit because it went bad and pegged the gauge all the time. It seems to me that the oil pressure was never much above 50-60 lbs in the past. I didn't know if this could be a blockage causing the pump to work harder or if it would be hard on seals.

 

[SteelHeadz]

FYI, the NORMAL operating oil pressure for a 4.0 and a 2.5 is from 37 to 75 psi. 13psi min. @600 rpm.

 

[kjegbert23]

Thanks for the info. It does seem higher than it's normal, especially on a motor with 160,000. I found an oil leak from the valve cover when I inspected it last night. That will be fixed when I do the oil change and thermostat on Saturday. All coolant hoses are pretty warn and will be changed next week.

 

[jps4jeep]

sounds like you have good oil pressure...

 

[volaredon]

sounds like you have good oil pressure...

I agree; but ran into a similar situation on my Cherokee; 167 K and all of a sudden GREAT oil pressure last week (this on a 4.0) it was the sending unit in my case. If they are showing that high (and it's not "normal" for your particular rig) it may be coming apart internally, and that plastic piece where the wire clips in, is just crimped to the threaded base; that plastic gets brittle over time; and can crack and leak; then you instantly pump your motor DRY and thats not good; a $40 oil sending unit later and mine's back to reading ~60 tops now.

That said, I had a 97 Ram with a 318. ANY TIME it ran, idle cruise, cold hot whatever; it never wavered from reading 40PSI; new sending unit didnt change it; I put a manual gauge on it and it went from a low of 20 Hot at an idle to 70 cruising down the highway; but that gauge still stayed at 40 constantly.