Low Oil Pressure Update

Ok when it is cold oil pressure is between 40-50 psi and the warmer the jeep gets the worse it gets. Before the oil change (I got yesterday) at idle it would sit at 10 then drop to 0 check gauges light would come on. And if it was left at 0 next time I started it you could hear the rockers clankin but if I turned the engine off at 10+ psi it would not do that. Now that I changed the oil Mobile1 Full Synthetic 10-30 problem still exits but I havent seen the gauge drop to 0 yet. Your thoughts?

Could have a bad pump, main bearings, rod bearings, or camshaft bushings.

i have this exact problem with me jeep. it need a oil change for one. im thinking of going up in the viscosity to see of that helps

First, don't trust the gauge. Hook up a mechanical oil pressure gauge and see what an accurate reading is.

What brand of oil filter are you running?

Also, which engine and what mileage on the engine?

Oil Filter is Valvoline* (Spell check)
Engine is 4.0 HO 135k
You still think I need to hook up a mechanical oil gauge even know when the pressure is low when I turn off the engine and when started again it knocks?

Jeemy B. said:

Oil Filter is Valvoline* (Spell check)
Engine is 4.0 HO 135k
You still think I need to hook up a mechanical oil gauge even know when the pressure is low when I turn off the engine and when started again it knocks?

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The electrical gauges on the dash are NOT accurate. A mechanical is the only way to be 100%.

I would, just for the peace of mind, or confirmation of a problem.

My 4.0, 1990 Renix with 137k original miles, rattles all the time, but the oil pressure is 20-ish at warm idle and 40-60 cold, and that is confirmed with a mechanical gauge. I run Shell Rotella 15w40 year round for the cleaning and ZDDP in it.

Mobil 1 10w30 is a great oil, and I have run it in a lot of vehicles. Not familiar with the Valvoline filters. Some filters have poor pressure bypass valves and tend to give lower pressure levels. I stick with the NAPA Gold, but Wix are reported to be good filters.

Also, someone recently posted on here that they had a low pressure condition, pulled the pan and found the pump pickup screen full of crap.

Long and short of it, rule of thumb is 10 psi for each 1000 rpm.

i had this same problem in my 92 cherokee limited. I pulled the oil filter housing off (because it was leaking) and got a new filter housing rebuild kit. It was about 13 bucks from the jeep dealership. Then i put in a new oil sending control sensor. I put in a new high volume oil pump from auto zone. When i put it all back together it hasn't had the problem since. It still idles between 40-60psi when cold and about 20 when its warm, and thats what it should be at (or at least what mostly everybody elses runs at). I would check that filter housing to see if its leaking though.

joe_peters said:

I stick with the NAPA Gold, but Wix are reported to be good filters.

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that's all i use. and napa gold filters are wix, as are the premium carquest filters.

Hellbent said:

that's all i use. and napa gold filters are wix, as are the premium carquest filters.

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I just bought 2 of them yesterday.