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Topic Review (Newest First)
05-25-2013 04:46 PM
metalharo9187 It only has 128900 miles, but still good to know
05-25-2013 04:22 PM
BCDonny as your motor ages with use your bearings get worn which also causes a decrease in oil pressure
05-25-2013 03:15 PM
metalharo9187 No water mixing or oil loss.
05-25-2013 01:36 PM
renegade X Or do a compression test as well. Are you losing oil or notice water mixing with?
05-25-2013 09:53 AM
metalharo9187 Lol thanks
05-25-2013 08:49 AM
0III0forlife First off, the YJ gauges are noted to be inaccurate. So this is most likely your problem.

If you want to investigate it further, buy a cheap manual oil pressure gauge like an autometer, and install it in the pressure sending unit hole. Which is located down between the distributor and the starter. A manual gauge has the 1/8th inch plastic line to give you a more true reading of the actual oil pressure.

If it is low, it could be that the oil pickup tube is clogged or partially clogged (it has a screen on the bottom of it). Its accessible by dropping the oil pan. Or, the oil pump is going out on it.

But I would think that its a gauge issue if you have been having this problem for 3 years and havent scattered that motor yet. 40 psi is normal, down near zero is extremely dangerous. Unless your ultimate goal is to see how tight you can get that motor to sieze up.
05-24-2013 03:34 PM
metalharo9187 Well I have had this issue for the past 3 years and didn't think much of it because it was like this when I bought it.
05-24-2013 03:27 PM
Shrub I have that same exact problem with my 92. But I'm running the 2.5
05-24-2013 03:11 PM
AllMudd Have you hooked up a oil pressure tester? I would try this to rule out faulty sensors or gauges. If the tester is reading incorrectly the. You have a bigger problem on your hands.
05-24-2013 02:00 PM
Oil Pressure issue! Need Guidance. 4.2L

I posted about this a few days ago but Im looking for more feed back.

Okay so upon cold start the oil pressure will start off at 40, then when it warms up drops to just above the first line, not zero. It will go up a little when engine rpms increase but not significantly. I have literally no leaks on the block because i've addressed them all. I'm running 10w-40 with a lucas stabil. Would appreciate feedback.

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