Sometimes my oil pressure gauge drops to 0 and the check engine light comes on. The motor isn't knocking or doing anything strange. Some have suggested it's a sensor, but no one seems to know what it's called for where it is located. What do you guys think I should do to fix it?

First off read your diagnostic codes. Many auto parts stores who have OBD scaners will do this for you for free. Or if you want to try the manual method, you can do it through the ignition. For the 1997, Without turning the engine on, turn the ignition key On,Off,On,Off and finally On. Do it fairly quick. The Check Engine light should begin to flash. Count the number of blinks, pause, then some more blinks. This is your error code.

Second, your Oil pressure sending unit is in the area above you oil filter. It screws into the block and has a wire plug connector on top.

Before replacing your sending unit, check the plug connections. Make sure they're clean and tight.

My YJ goes through oil pressure sending units about every year. The gauge will begin to be erratic, then fail at either 0psi, or peg the needle. Aother thing to do is get a direct reading gauge and route it into the Jeep and see if it does the same thing as the dash gauge. Chances are, it's the sending unit.

I have the exact same problem with my 97 TJ. I put it on a mechanical guage, and it was fine. This made the problem more of an annoyance then an actual problem. I then replaced the sending unit (I was getting pretty annoyed)and the problem did not change. I just hung up with a friend at a Jeep dealership, and he said that there is an erratic oil pressure flash update that might fix it. I will post next week with the results.

Woo Hoo Its Gone!!!!!!!!!!!!

I had my ECU flashed today. We found a flash that addressed the problem exactly.

The problem has not manifested itself since then in situations when it ordinarily would have.

This fix appears to have worked. I will not be driving my Jeep until next week, so I will have more time to test it then and will post with any dissenting results.

I'll have to drop by the Jeep shop and see if they have such a thing for YJ's!

I think they have one for later model YJ's. We were going through the list of flashes and a few of them were pre 97.

quote:

Originally posted by Stogie25:
Woo Hoo Its Gone!!!!!!!!!!!!

I had my ECU flashed today. We found a flash that addressed the problem exactly.

The problem has not manifested itself since then in situations when it ordinarily would have.

This fix appears to have worked. I will not be driving my Jeep until next week, so I will have more time to test it then and will post with any dissenting results.

Could you explain what having your ECU "flashed" is all about? Also was this something you had the dealer do? Cost?
Thanks!

The dealer is the only one who can flash your ECU. The flash is the software burnt into the Electronic Control Unit. That was the first time my Jeep had been back to the dealer since I bought it in February 1997.

I am not sure what it would cost you. It cost me a 12 pack (I have a friend in parts there). The whole operation took about fifteen minutes.

As the problem is generated by Jeep's software, I say it should be a recall repair, but good luck trying to get Jeep to agree to that.

We have a 2001 Jeep Grand Cherokee with the 4.7l that started the same issue. Oil pressue drops like a rock after about 15 miles and it is hot. Went to locale Jeep dealer and the only flash they can find is about timimg. Is that the same flash? Does your friend have the file name or version #? Thanks