00 cherokee - no codes displayed

snipped-for-privacy@verizon.net did pass the time by typing:

Oil pressure doesn't set codes.

The sensor wire fell off.

Thanks for reply with links Doug. I'll check the wire out tomorrow first thing. I didn't think that oil pressure would set codes, but thought that an electrical glitch might cause all three probs at once. The rough running, check engine light and high oil pressure display all at the same time were too much of a coincidence or me.

Regards, Bob

yzordderrex did pass the time by typing:

Rough run can be caused by a corroded engine ground strap, but starting in 93 they used a cable. It looks like the 00 might watch oil pressure and put the engine in "limp home" mode, but the only sensor code I see is for "Oil pressure sender problems"

I'm still guessing the connector is corroded or came loose.

As for codes, try here.

That, or the sending unit has failed open. It's such a simple and common part to fail that having a spare on hand is not a big deal - you'll need it sooner or later (probably sooner).

Doug, Will, thanks.

So this morning I go outside, pop hood open, and wiggle wires around to the sensor. (I'm pretty sure it is the sensor. Just forward and above the filter) Get in and now check engine light still on but when I start I got 40 pounds of oil. Back in the house and leave a note for the kid that I'm taking her ride to work. Start the car back up and pressure goes back to 80 pounds. Shit! Get to work ten minutes later and trying again to read the codes. No codes, but I notice that when I turn the key on the oil pressure gauge is at zero. Usually with key on it's pegged. So I start her up and pressure goes to about 40pounds, then about 5 seconds later it's pegged again.

regards, Bob

yzordderrex did pass the time by typing:

That's sounding more like a failed sensor or wiring. The sensors are not too overpriced.

I would clean and tighten the connection first. I prefer to use a spray contact cleaner you can get from electronic shops on our Cherokee connections. I do all of the sensor ones every couple years on my old beast.

The connector might be a push on type that can need to be tightened.

Mike

If you fix the oil pressure sensor issue and still have rough idle, try a set of new ignition wires. Near as I can remember, every time I first noticed a set of wires had gone bad, it was always on a really wet day.

Steve

snipped-for-privacy@veriz> My daughter just bought a 00 Cherokee Sport with a straight six last

If you have a can of WD-40 handy try spraying all the ignition wiring, coils, etc. If it makes a difference then you have a moisture problem.

If you stop by auto-Zone, Advanced Auto, etc they will lend you a DRB_II code reader to see if any are showing up.

I am surprised that nothing shows on the odometer. There are apparently a couple versions of the software that require different numbers and speeds of cycling the ignition off-on. Did you try it 3,4,& 5 times? Did you allow the odometer to show something briefly before the back cycle?

Can you hear or see any sparks jumping when the engine is idling and the hood up?

Do we understand the Jeep ran fine up until it started raining?

Did she drive it through standing water? I had a Dodge Dart Sport that would drench the distributor if I went through deep water at speed.

Have you asked the previous owner for input?

If you have a can of WD-40 handy try spraying all the ignition wiring, coils, etc. If it makes a difference then you have a moisture problem.

Is it now in the garage or out in the rain?

If you stop by auto-Zone, Advanced Auto, etc they will lend you a DRB_II code reader to see if any are showing up.

I am surprised that nothing shows on the odometer. There are apparently a couple versions of the software that require different numbers and speeds of cycling the ignition off-on. Did you try it 3,4,& 5 times? Did you allow the odometer to show something briefly before the back cycle?

Can you hear or see any sparks jumping when the engine is idling and the hood up?

Do we understand the Jeep ran fine up until it started raining?

Did she drive it through standing water? I had a Dodge Dart Sport that would drench the distributor if I went through deep water at speed.

Have you asked the previous owner for input?

It was a broken plug that was causing the rough running and check engine light. Not sure if the high oil pressure displayed was related or an intermittent sensor or what. Daughter brought it back to her mechanic and he admitted he must have broke plug somehow putting it in. He ordered a pressure sensor but she said it's working ok no prob.

thanks, Bob

Thanks for getting back with the fix.

JoBo