So,my oil pressure was reading 10-15 at idle and 40-50 at throttle,this concerned me a little so i changed my oil with a mopar filter,15w40 rotella,and put in a new bwd sending unit.

All was fine,20 at idle 60 at throttle.I parked for a few hours and started to drive home and noticed it was 70-80 at throttle and 50-60 idle.Obviously this alarmed me,but then i started to notice it would go 60-70 weather i was on the throttle or not,and would actually go down while accelerating.

I realize a faulty new unit is possible,but how often does that honestly happen?If its not that,what could it be?



Specs: 98 cherokee,4.0,265k.

 

Where'd you get the new one from? It happens all the time. I'm on my 3rd sending unit cause the first two new ones didn't work

 

My work,advance auto.

 

You really shouldn't worry about it. 99/100 times if the gauge is reading high like that, it's the sending unit is faulty. I have no idea what the other 1/100 would be caused by though haha. You can stick a mechanical gauge on it and get a real reading though if you're really worried

 

I'll be watching for what you find out.

I put a remanufactured ATK longblock in mine. Once the engine gets hot, I have 8-10 PSI at idle, and 40-45 PSI at anything above 1500 RPM. Given that it's a new engine, this REALLY wigged me out at first. But I'm not overheating, I have no ticking or unusual noises, so I've kind of relaxed about it. But I still find myself watching the gauge all the time. Obviously, I'd feel better if I were in the 15-20 range at idle with a new motor.

If I could humbly ask...
It would be great if, even after you resolve your possible sending unit issue, you could report back after some time to let us know how your choice of oil has affected your pressures.

Thanks and good luck!

 

guages just give us something to worry about.mine,all of them are all over the place.

 

Buy your oil pressure sending units directly from Jeep folks.

Aftermarket ones are "hit and miss" with a lot of miss.