Mechanics

OIL PRESSURE IS HIGH

1995 Jeep Wrangler

Engine problem
1995 Jeep Wrangler 4 cyl Four Wheel Drive Manual 112000 miles

I am apparently having problems with high oil pressure. My oil pressure gauge was reading 80 and above on a recent trip with interstate travel, engine rpm @ 3000 and above. At idle it would drop to 40-50 psi. After returning home and driving around for a couple days my oil sending unit blew its internal gasket and I lost almost all my oil. I installed a new oil pressure sending unit and performed an oil and filter change. I'm still getting psi reading on my stock gauge of 70-80 around town and about 40-50 at idle. Any place to start checking for this problem would be helpful, thank you!
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Lervin
December 26, 2007.




Could be that the gauge is off. Have a manual gauge installed to verify the pressure is the same that the gauge says it is. What weigth oil are you using and what is the temp where you are at?

Tiny
Jack42
Dec 27, 2007.
Our temperature here (Omaha, Ne.)Probably averages 30 degrees F. During the day. My jeep manual says below 60 degrees f. I can run 5w-30 so I have switched to that. 5w-30 valvoline durablend. I am currently trying to locate a mechanics type oil pressure gauge to check the oil pressure properly. One of my concerns is that the oil pressure is truly high and that is why the old sending unit blew. What due you think about running Gunks' 5 minute oil flush if I do find the oil pressure is high. Also having a proplem locating an oil pressure gauge to buy. Also Ohmed new sensor (just in case) it is not OL, voltage at plug is around 6.5 to 7.5 volts (hard to get a good ground). About two weeks ago I installed a new clutch kit and had flywheel resurfaced. I really don't feel this has anything to do with oil pres. Problem but just in case!

Tiny
Lervin
Dec 27, 2007.
Bought an oil pressure gauge, found one at Harbor Freight Tools. Jeep has been in heated garage for a couple days at 65 degrees f. Installed gauge at oil pressure sending unit port, at cold start up pressure was around 75 psi. The pressure varied a lot even when high idle was done. It would stay at 50 for 10 seconds or so then jump to 65 and stayed around 60 for the most part. When running engine between 2000 and 3000 rpm oil psi was around 65 to 75. Once the engine reached full oper. Temp. The psi dropped to around 38. Fairly steady there until I noticed it would jump to 45-50 for a second. At about 1500 rpm and f.O.T, 60 psi. Dash gauge with new sending unit reads the same pressures. No clue. Please help!

Tiny
Lervin
Dec 27, 2007.
I dont recommend any kind of engine flush. If you have the correct oil filter, this could be a problem with the oil pump. They have springs in them to keep them from doing this kind of thing. Since yours stays then jumps, it could be a broken spring in the pump moving around and sticking in different spots

Tiny
Jack42
Dec 28, 2007.
This is what I needed! I will install a new oil pump.

Tiny
Lervin
Dec 28, 2007.
Just thought I'd let you know that I installed a new oil pump shortly after my last post. It steadied my oil pressure, but oil pressure has still been high. Although it is much more consistant, 60-80 psi all the time. I am going to do a little research to find out if the aftermarket oil pump has a diff. Spring rate on the oil pressure regulator as compared to OEM. It's very annoying though.

Tiny
Lervin
Nov 26, 2008.
Make sure the passageways between the pump and pressure relief valve are not blocked. Try a new oil filter if you haven't done so. Although for the weight of oil you are using pressures of 60 psi are quite normal (and is good) for initial startup. 30-40 psi is a perfect range for floating main and rod bearings at operating temperature. Is it a synthetic or mineral 5-30W motor oil?
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Tiny
Airsoftsoldrecn9
Nov 26, 2008.
Actually I am using 10w-30 fully synthetic (Napa house brand, it's cheaper and made by valvoline). The oil psi is as follows: up to 80psi on cold start, drops to between 50-60 psi at idle after fully warmed up (30 to 45 minutes of driving) but while driving after warm up it runs at about 60-70 psi. Oil filters used - k& n (to expensive but I really like the one inch nut for removing filter), Napa gold (seemed to make oil pressure higher), and Mopar filter seems to be doing o.K. But no significant drop in oil pressure.

Tiny
Lervin
Nov 29, 2008.
Did you check the pressure relief valve?

Tiny
Airsoftsoldrecn9
Nov 29, 2008.

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