Hows my oil pressure?
#1
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Location: KY
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Year: 2000
Model: Cherokee
Engine: 4.0
Hows my oil pressure?
Im not having faith in the OEM gauge so I hooked up a aftermarket mechanical to hopefully diagnose a faulty sending unit. a couple times the OEM bottomed out and kicked the low pressure light on, after installing the aftermarket gauge, it reads virtually the same except it didnt drop below 8-10psi at idle like the OEM did. other readings show 28-30psi at 2000 RPMs, 20-23psi at 1750 RPMs.
Any thoughts on the matter?
Also fwiw, when I done a oil change, I read these 4.0s have a 6qt capacity but it only took 5.5qts with filter change to bring it up to full, Im thinking/hoping gunked up with a failing oil pump, this is a 2000 XJ so you see my concerns....thanks
Any thoughts on the matter?
Also fwiw, when I done a oil change, I read these 4.0s have a 6qt capacity but it only took 5.5qts with filter change to bring it up to full, Im thinking/hoping gunked up with a failing oil pump, this is a 2000 XJ so you see my concerns....thanks
#3
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Year: 1989
Model: Cherokee
Engine: 4.0
Oil pressure drops with mileage due to bearing clearances opening up. Although a higher flowing oil pump may produce a higher residual pressure, it is not likely the oil pump at fault for your lower oil pressure.
#4
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Year: 1999
Model: Cherokee
Engine: 4.0
The oil pressure spec for the 4.0 is as follows:
*Not less than 13 psi at HOT idle
*Between 37-75 psi over 1600 rpms
If you are seeing verified oil pressure of around 8 psi at hot idle which from your post it sounds like you are, that indicates a problem with a "clearance" somewhere in the engine. Could be an oil pump, but a more likely suspect is the engine bearings.
With an 00-01, you have the infamous 0331 cylinder head, which has a bad habit of cracking between cylinders 3-4 on some unlucky vehicles.
The #1 symptom of a cracked 0331 head is "unexplained coolant loss". You need to be watching the level of coolant in your coolant reservoir like a hawk. Are you losing any coolant?
*Not less than 13 psi at HOT idle
*Between 37-75 psi over 1600 rpms
If you are seeing verified oil pressure of around 8 psi at hot idle which from your post it sounds like you are, that indicates a problem with a "clearance" somewhere in the engine. Could be an oil pump, but a more likely suspect is the engine bearings.
With an 00-01, you have the infamous 0331 cylinder head, which has a bad habit of cracking between cylinders 3-4 on some unlucky vehicles.
The #1 symptom of a cracked 0331 head is "unexplained coolant loss". You need to be watching the level of coolant in your coolant reservoir like a hawk. Are you losing any coolant?
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