Low oil pressure and other problems, PLEASE HELP ?
 

Hi everyone,
I have a 1996 jeep cherokee 2.5 TD Limited SE with many problems to solve. Firstly and most importantly is the low oil pressure.

I spent a small fortune having my jeep serviced etc, but recently on a trip to help move my girlfriends furniture out of her flat my jeep died on a busy high st in south London.
I opened the bonnet fearing the worst to discover the fuel filter had come unattached and there was fuel everywhere. The garage who had serviced my jeep had used the wrong sized washer to hold the fuel filter on. I cut it to size put the filter back on, primed the fuel and got her going again, but since then I get a flashing light on my dash saying CHECK GAUGE! This is due to my oil pressure gauge regularly falling to '0' and behaving very erratically.

Is my engine knackered?
Or could this be a faulty pump or Senser?

If I go on the motorway for more than a couple of hours I lose water and my radiator light comes on but I never overheat? And there is no sludge in the radiator filler bowl.

Even with these problems my Jeep drives well, a little sluggish but she is an old girl. I have spent so much on her and dont want to spend much more unless I can identify the engine problems first. Does anyone have any suggestions as to what these problems indicate and if they can be fixed relatively cheaply? I love my jeep and would hate to have to get rid of her.

Any help would be greatly appreciated?
Cheers,
Romulus.

Your oil sending unit has a connector connecting it to the wiring harness, Separate the connector and see if it has gasoline (called petrol on your side of the pond) in it. Clean it with some contact cleaner. When two problems happen at the same time like this, typicaly one caused the other, I doubt your engine is "knackered". If cleaning it fails to help, change the sending unit. Let us know what you find.

Thanks

D

X2 on the sending unit...Tj

oil pressure issues
 

I have two 96 cherokees --- 4.0s--- one of them lost all oil pressure after i just changed the oil and oil filter -- zero pressure on the gauge--i called some 4wheelin friends--they said check the oil pressure sending unit--sure enough i must have bumped the sending unit when putting in the oil filter from topside-- the sending unit is connected to the block -- the receiver / connectors were still in tact -- but i broke off the unit. I changed out the sending unit and viola!!!!! i got oil pressure gauge working again...:grin:

With respect to fuel issues -- im not so sure how to help there...

Best Wishes,
Charlie

oil pressure probs
 

Thanks for your help guys, the more and more I think about it the problem does sound like a faulty sensor or sending unit. As I am new to jeeps could anyone describe or show me where the sender unit is located.
Many Thanks,
Romulus.

Not many of us on this side of the pond have any knowledge of this engine, as it was not offered here. Someone will come along to help but it may be a little bit.. best of luck.

Hi!
I have a similar problem, my oil pressure is lower than the last time. In the first couple of seconds I got the flashing red CHECK GAUGE light too. I am tryin to locate the oil pressure sensor to see that thats the problem or not.
I have enough oil in the car, viscousity is great, I have power, no unusual sounds.
Somebody can tell us where is this unit located? I try my best under the car, but I see nothing that looks like the sensor. And I cant find the wirings to help me.
Thanks in advance!

Usually it's close to the oil filter, but not always. It's a small sensor screwed into the block with tapered pipe thread and has an electrical connector clipped to it. You could buy one or look it up in a catalog to see what it looks like, then look the engine over to see if you can find it.

https://www.uscars.biz/uscars/jeep-d..._vm_diesel.pdf

Thanks dave1123!
I found it. I contact-spayed it, in hope that it helps. After 10 minutes, I started the engine. still at 2 bar, doesnt really respont to the throttle. I will change the sensor, hopefully it will resolve the problem.
Thanks again, and sorry for my bad english! Have a nice day.

According to the FSM linked above, the oil pressure should be 3.0 - 4.5 bar at 4000 rpm. There's also a pressure relief valve inside the oil pan that blows off at 6.5 bar. The spring in that could be weak or broken.