bbbngowc

Hi All,

Glad I found this site!

I have a 1998 Grand Cherokee Limited, 4wdr V8 with the 5.2L engine and it's reading zero oil pressure.

The other night, my brother needed a ride home, so I took him home. On my way back from his house I notices the oil pressure gauge reading 0. Never moved and engine light never came on. Got the Jeep home and checked the oil level. It's fine. I just changed the oil less than 2 months ago.

Yesterday I went to check on the jeep and turned on the ignition, still reading zero. I started the jeep and there was a loud rattling sound that went away after a few seconds when the jeep idled.

Where should I begin troubleshooting this issue?

Oil Pressure Sensor?
Oil pump?
Change the oil to a more heavier weight (currently has 10W-40)?

bbbngowc

I had someone come over and have a look at the car. They said it's the oil pump. Anyone want else want to chime in with a suggestion?

seed

If you actually had "zero"oil pressure,you wouldn't be driving around. I would start with the sending unit.

bbbngowc

Well I'm not driving the jeep. I drove it home and haven't moved it since. Thanks for the tip. I had another mechanic come have a look at they also said the oil pump.

Anyone ever did this? Is it a heavy job. I do a little tinkering with cars, so I'm up for the challenge if it's not too much of a job. From what I can see, I just need to drop the exhaust pipes and should be able to slide the oil pan out the back?

bbbngowc

So I'm getting ready to do the oil pump change. I drained the oil and was about to start unbolting the exhaust pipe cause it's in the way, when I noticed another section behind the oil pan that can be taken down.

My question is: Do I have to remove the front part (where the oil drain plug is) or this back part or both? Where is the oil pump in this jeep?

seed

i don't quite understand your question. The pan is one piece and yes,it needs to be dropped to get to the pump,you will have to drop the starter and exhaust and maybe the crossmember to get the exhaust down.

bbbngowc

great. Thanks.

ol"blue

I'm sending you a Private Message.

nyfreakinrican7

I've been driving my 96' GC with a 5.2l for about a year with that oil gauge going to zero. If your oil pump was not working the engine would have locked up. Check the oil pressure sensor it's like $30 but it's better than changing the oil pump and having to still get the sensor. Its located to the left of the distributor. Mine was cracked.

bbbngowc

Well I don't drive it because I didn't want to run the risk of the engine locking up. You said, your oil pump "going to zero"? Meaning it drops while driving? Mine never moves from Zero. When I start it, I can hear the valves clattering and it doesn't go quiet. My dad looked at it and he said the oil pump is not pumping oil into the valve area to quiet them. I've had 3 people look at it and they all said the same thing. Oil Pump. I already drained the oil and started loosening bolts. But it is a headache!

If the pump was not working, how long would it be before the engine locked up? When the oil pressure dropped to zero, I was about 6 miles away from home and I drove it home no problems. Just zero oil pressure. Haven't drove it since.

I should just change the sensor, put oil back in the pan and check it huh?

bbbngowc

I got as far as the exhaust pipes. Got all the bolts undone, but it's just sitting up nice and solid. They're suppose to drop once the bolts are undone right?

What now?

seed

like i mentioned above,your cross member will probably have to be dropped,is that whats holding it up?

tsconver

did you put a mechanical gauge on it and see what the oil pressure was? Seems stupid to drop a pan and replace a pump without knowing the actual oil pressure from a mechanical gauge, takes 15 minutes to check and you can get the gauge at a autozone or similar for next to nothing.

bbbngowc

Nah it doesn't look so. There's about 3" of space between the cross member and the exhaust pipes. The exhaust is like it's still bolted somewhere. It is not even the least bit shaky.

bbbngowc

Well too late for that now. I've already drained the oil, unbolted a lot of bolts, taken out the starter, dropped the inner tie rod ends (long story ) and dropped the oil pan (just not far enough).

Only thing left is to move the exhaust pipes and lower the pan enough to where I can get to the pump. Put it in and bolt everything back together again.

Thanks for the help so far. Keep the tips coming. We're almost there.