dbcooper1999XJ

Need advice on wandering oil pressure. I have a 1999 XJ with 106,000 miles. On my way to work my pressure gauge went down to 0 PSI this morning. I immediately pulled over and checked my oil level. All was fine, so I got a ride to work from a coworker. At lunch I went back to tow it to work and I turned the key on and the gauge went up to 20 PSI, so I started it. All was well. Driving home my gauge started to drop again and I noticed when the engine was at idle the pressure was near 0 but gassing the motor boosted it up around 20 PSI. Any help with these symptoms; loose wire, bad pump?

Tural

you basically answered it. could be the gauge or the pump. i'm new to jeeps, but bad oil pressure seems strange for any vehicle with 106,000 miles. i would try out the gauge first. but if the gauge was bad, more than likely it wouldn't climb back up when you give it gas. but it's still a good possibility.
when was the last time you changed the oil. you could have something as simple as trash on the pickup tube.

dbcooper1999XJ

It is due for one, I guess that is the cheapest fix to start with. See where that takes me.

mike albo

change the sending unit first see what happens,it may be going bad

Throttle Jockey

you said when you went to get it you turned the key on and it showed 20psi on the guage then you started it. you should not show an oil pressure reading if its not running. sounds like the sender may be going out.

sbslinde

Do not change any parts, yet.

I was running 5w30 oil in my 2000 w/46k and had low (light coming on) oil pressure at idle, warm.

Changed to 10w40 and now I have 20psi at idle, warm.

No other changes.

Jeff

wilco40

Factory (electric) gages are KRAP! Go to your favorite parts store & get a mechanical one. It's worth the hassle.

19558077

the pressure could be dropping as the oil heats up like mine does,and it only has 128k, and about to blow. i would put a manual, liquid filled pressure guage to get an acual reading before you go sticking parts on it.

dbcooper1999XJ

I like the mechanical gauge idea, there's nothing like actual readings to ease your mind on the goings on in your engine.

Thanks for all the input.

MS Fowler

Take a look at this link:
http://www.olypen.com/craigh/pressure.htm

dbcooper1999XJ

This is great info, thanks for sending.

quickster2

We use Rotella T 5W40 synthetic which corrected the low oil pressure situation and quieted up the engine. Definitely verify pressure with a mechanical gauge before spending any money.