oil pressure

hello, i have a question i have found to be answered on this news group, but never specificaly to my jeep. i have a 2000 jeep grand cherokee V-8 5.2L all wheel drive.70,000 miles

just recently the oil pressure started dropping. when driving, the pressure is fine but when at a light or in park it drops to just above zero and the light comes on.if you put it in nuetrel or park and rev the engine the pressure goes up and down with the engine rpm's bu this doesn't always happen, sometimes the pressure stays fine, anyone have any ideas, i am going to florida on friday. thanks Joe

Reply to
pooteo
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The answer is the same for pretty much any vehicle. Either: (1) Your pressure is in fact low, and you need to find out why and get it fixed, or (2) The pressure sending unit is out of calibration and not reading correctly. Sometimes this is due to a leak internal to the sending unit

- and the condition can vary with temperature and the degree of leaking and internal presure throwing the reading off from day to day - which would go along with the inconsistency of the problen that you are seeing.

Hopefully it's (2) - and chances are good that it is. You can do one of two things: (1) Have the pressure checked - actually measured with a known accurate gage attached to the pressure port, then go from there depending on what you find (i.e., if true pressure readings are fine under *all* conditions including the stopped-at-light one, then you know it's the sending unit) or (2) Replace the sending unit and see if the problem goes away.

There is a very good chance that it is just the sending unit. If you simply go ahead and replace the sending unit, it might be advisable to have the pressure readings done anyway just to make sure the new sending unit is not wrong and giving you a false sense of security. The extra you spend for the pressure reading with a gage would be considered insurance against ruining your engine.

The choices are yours.

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')

Reply to
Bill Putney

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