5.2 eratic oil pressure! HELPPPPPPP!!!!

[bcr2887]

Ok guys pulling my hair out here!! I have a 97 jeep grand cherokee. 5.2 liter motor 160000 miles. Started it up about a month ago and everything was fine, then it lost oil pressure. stop the motor for a minute and started it back up and it had oil pressure for a few minutes and then dropped. changed the oil and filter thinking maybe a clog, but no!!! so next i changed the oil pump(what a bitch) well had good oil pressure for around 35 or so miles drove it the next day to the store and back let it idle in the drive for about 15 minutes and left again thinking everything was fine 2 minutes down the road away went the pressure again( arghhhhhhhhhhh) anyway thought maybe if it wasn't the pump it might be clogged passages but drove fine for that time after changing the pump. I can shut it off for just a second after the pressure goes away and start it right back up and it will have pressure and might keep it for a minute or two.(wtf) anybody have any ideas???????!!!!!!!! please help!!!!!!!!

[JDPascal]

Check the oil pressure sending unit.

The connections to the sender get kinda flaky once in a while and can cause problems. Or it could be the sending unit is gone south too....

you will find it on the passenger side of the distributer at the back of the engine block. Not easy to get at and most likely need a special socket to get it out.

JD

[bcr2887]

No unfourtantly it is acctually loseing oil pressure!

[JDPascal]

what makes you think the oil pressure is actually disappearing?? does the engine make any new noises when the gauge goes to 0??

[bcr2887]

Oh yeah it starts pinging pretty bad!( guess i forgot to mention that)

[JDPascal]

Do you think that the "pinging" could be hydraulic lifter noise?

I would install a mechanical oil pressure gauge along side the stock electrical one. That will tell you for sure what the pressure is doing.

Somewhere in the distant recesses of my memory, there is a picture of a service bulletin about this. Something about a plug that comes loose and floats back and forth in a passage just below the pressure sending unit.

It will take me a day or so to search back in my papers to find it but I will look.

There is also a TSB for the 1996 JGC, 5.2 where the sender is changed and the PCM is reprogramed to cure an erratic needle fluctuation. Yours is a 97 but I'll find that TSB too.

JD

[bcr2887]

Yes to the lifters clacking! The plug sounds like the best answer i have heard so far! I have heard of other 5.2's doing this on other forums but it never got to the cure! Thanks for any help!!!

[BLAZT]

My Jeep is a 93 GC. I had the same problem. All I did was to replace the Oil Pressure Sending Unit. It was about $ 35.00. And problem Solved.

[JDPascal]

Well, according to bcr, there is lifter noise when the pressure indication goes south on him. If that is the case, a sending unit won't help but I would still install a mechanical gauge even if it is mounted under the hood, so the pressure can be varified when ever it happens.

JD

[bcr2887]

thanks for any help u can come up with on that service bulletin! i drive truck so it might be a couple of weeks before i get to check back in! got to leave early in the morning. i was kinda hoping to get the problem fixed b4 i left but maybe next time!!!