jeeper31

Took truck to store and was sitting in parking lot idling when the check gauges light went on. Checked out oil pressure gauge and it read 0. I had the oil changed a week ago and havn't driven the car much since so I was confused. (Oil seems to disappear. No leak but I was told that It's normal for a Grand Cherokee with 117,000 miles to lose up to a quart for every 1000 miles) Anyway, I checked the oil level and it was fine. Started the car up and found that when just idling the pressure reads 0 but when I start to drive the pressure comes up to a somewhat normal level. When I stop the pressure falls again. So here are the questions:

1) What's the problem?
2) Is it serious?
3) Can I drive it the way it is?

The truck is a 2000 Grand Cherokee with about 117,000 miles (yes I drive a lot).

I know this is not a Porsche but I have nowhere to turn.

Thanks in advance for all the help.

marky522

I would suspect the sending unit if there is no noise with the lack of oil pressure, I would NOT drive it because there might actually be an oil pressure problem, unlikely though, but hey who knows, I just sold my dakota that had 219K orig everything. Good luck!!!

Mark

jeeper31

What kind of noise would i hear? When you say sendig unit you mean the unit sending the signal for how much pressure there is?

marky522

You would hear a racket coming from the engine, it'll tell ya if it has no oil pressure, you'll hear ticking and clanking. Yep, the oil pressure sending unit. So the first thing you need to ask yourself is did it sound any different when it happened? Either way I would reccomend getting it looked at before starting it again, I jsut dont want to hear about your engien seizing.

MArk

jeeper31

The engine definatley sounded ok. I did not notice anything different in the way it sounded. Drove it about 2-3 miles after I noticed the problem and it seemed to ride fine. IS there any way I can check the unit myself?

marky522

I did a quick serach and it is a known problem, I found one post saying that the person had 41K on theres and it happened, they took it to the dealer, he dealer said it was not the sending unit but the oil pump its self, they replaced it and the problem came back after about a month. Let me do a little more digging can you give me the engine size?

Mark

jeeper31

It is the 8 cyl. I think it is the 4.7 l. I will check.


And thanks for your help

jeeper31

Yep. 4.7L V8.

marky522

ok, i am now retyping this cause i refresehd on accident DOH!!!!!

chances are it is your gauge, they are known to be flakey, i would get a manual gauge and hook it up to see what you are really getting for oil pressure, I found another post saying that a guy runs a aftermarket gauge next to his stock one due to the fact the stock one flakes out like that. Still be careful again i dont want you to hurt your engine!!!! I'll keep digging

MArk

marky522

your sending unit is on the driver side front of the engine right above the oil filter.

Mark

jeeper31

If the sending unit is sending a pressure reading while the car is in motion would it still be a faulty unit. That would mean it stops sending a reading when the car is not in motion.

marky522

hey jeeper, do you have a check engine light now? You probably should. If you do, go out to your car (if possible) Turn the ignition key until the digital odometer displays, repeat three times in succession and then back to "On" (On/Off, On/Off, On/Off, On). At the fourth "On" the odometer will be replaced with codes. If no codes are present then "Done" will appear.

let me know what the codes are.

MArk

jeeper31

ok. I will do that. Although I should tell you that the check engine light has been on for a while. I have a gas leak. I also have a code reader will try that. Back in a few.

marky522

http://www.ilovejeeps.com/forums/sho...8555#post88555

That post is you baby!!!!! I really think its your sending unit,

and here is another

http://www.jeepsunlimited.com/forums...hreadid=591731

jeeper31

Mark,

Bizarre... No new codes, only the ones that were there before. I turned car on and let it run for a bit. Oil pressure came right up to normal level and stayed there. Doesn't seem to be malfunctioning now. Go figure.