Another Oil Pressure Question
#1
CF Veteran
Thread Starter
Another Oil Pressure Question
As some of you may know, I replaced my RMS this past week (yes, the entire week). I finally got everything buttoned up on Friday night but didn't really drive it until yesterday. I noticed that my oil pressure was about 10 psi lower than what it had been. I wasn't worried about most of it but my warm idle is low, 5-6 psi (almost 50%) below minimum factory recommendation.
Pre RMS
Cold Idle: 35-40 psi
Warm Idle: 15-20 psi
2000 RPM: 40-50 psi
Post RMS
Cold Idle: 30 psi
Warm Idle: 8 psi
2000 RPM: 38 psi, max
I torqued the rear main cap first at 40#, then 70# and finally at 80# and I oiled the bearing before reinstalling. Could this be caused by an issue with the rear cap bearing? Or should I not be concerned. There are no unusual sounds in the engine. No knocking, clunking, or ticking and it seems to perform exactly as it did before my week-long ordeal. Temperatures are normal. I just don't want to blow it up. I'm using a WIX filter and Mobil1 10w-30 oil. The MOPAR sender was replaced about a year ago when I did the cluster swap and I confirmed that the connector is clean and firm.
I'm going to be at the Long Beach Grand Prix all day but will check back when I get home.
Pre RMS
Cold Idle: 35-40 psi
Warm Idle: 15-20 psi
2000 RPM: 40-50 psi
Post RMS
Cold Idle: 30 psi
Warm Idle: 8 psi
2000 RPM: 38 psi, max
I torqued the rear main cap first at 40#, then 70# and finally at 80# and I oiled the bearing before reinstalling. Could this be caused by an issue with the rear cap bearing? Or should I not be concerned. There are no unusual sounds in the engine. No knocking, clunking, or ticking and it seems to perform exactly as it did before my week-long ordeal. Temperatures are normal. I just don't want to blow it up. I'm using a WIX filter and Mobil1 10w-30 oil. The MOPAR sender was replaced about a year ago when I did the cluster swap and I confirmed that the connector is clean and firm.
I'm going to be at the Long Beach Grand Prix all day but will check back when I get home.
#3
CF Veteran
Thread Starter
I'm going by the dash gauge which may not be particularly accurate but I'm using it more as a reference for before and after. Whether the gauge is accurate or not, it would be odd that something would randomly happen to the gauge or sending unit to cause it to show >10 psi less than it did before I tore into the important things on the bottom. So, assuming it's accurate (until I can rent a mechanical pressure gauge), should I be concerned?
#4
CF Veteran
Thread Starter
Just a quick follow-up. My oil pressure has miraculously fixed itself. A couple days ago I noticed that it was back up to normal, which means about 40 psi cold idle, 45 psi 2000 rpm, and 20 psi warm idle.
#5
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
So you did a RMS in the same time as it took bummerjeeper to do a valve cover gasket?
I'd be proud if I were you.
Probably just a coincidence. Still happy to hear it.
I'd be proud if I were you.
Probably just a coincidence. Still happy to hear it.
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