oil pressure question

[88swampedmj]

whats the normal oil pressure supposed to be at on a ho 4.0 with 10w 30 oil?..

 

my motor sits at 40 or so pressure as i start then as it starts to warm up the oil pressure drops to almost 30

[JeepcoMJ]

It's fine.

[Eagle]

13 psi minimum at warm idle, 37 to 70 psi above 1600 RPM, according to the factory service manual.

 

Typically, most 4.0Ls in decent condition seem to run between 45 and 55 psi at highway speed.

[88swampedmj]

haha k, just wondering iam really paranoid now i guess since my other 4.0 blew the heck up

[Twisty]

Yeah, I run mine with 10W40 and what Eagle said sounds right. About 40psi around town and 47psi on the highway. When I come to a stop it goes down to about 17psi.

[Oizarod115]

mine runs near 20 on idle, skyrockets at WOT. never hits 80 though

[88swampedmj]

well whats weird about mine is. at idle its about 30-20.. but when i start it up cold its around 40.. then as the truck warms up its around 40 driving and 30-20 at redlights.. but on the highway it goes down to 30-20 while in 5th gear doin 70 or w/e.. that made me wonder

[Duner]

Most important thing to remember is that the gauge is moving so should the oil. If it quits moving the engine quits shortly after that - ruling out of course that the sender or gauge actually failed. Most engines can survive with at least 7-10 psi at idle. When my dad had he scout's engine rebuilt it had about 8 psi at idle on a certified oil pressure testing gauge he didn't trust the gauge in the dash until after the test. When he brought this up with the IHC (International Harvester Corp) parts guys they all came out to see the truck because they said when they rebuild those engines the oil pressure is usually 0-2 psi at idle. So I think your engine should be ok don't be so paranoid and enjoy til the mud seeps in over your dash board.

[pingpong]

So when my gauge read 3-5 while running on the side it is bad :eek:

[Duner]

I guess you are ready for the dry sump setup now. or atleast an accusump that way you can maintain pressure while rolling over

[pingpong]

No.. its time to swap in a new motor :D To many times on its side, and its been rebuilt once :eek:

[mjeff87]

Pat....and anyone else in the greater VA area for that matter....the guy I got the D30 and 242 from last weekend has a ton of Jeep stuff he's trying to unload. Included in the mess are at LEAST 3 4.0's, and 4 or 5 AW4's, plus a ton of sheetmetal parts (hoods, fenders, etc.)

 

Just in case anyone needs parts. He's about 20 miles the other side of Fredricksburg (Rhoadesville). If anyone wants, I can put you in touch with him. He goes by "non-stick" on NAXJA (his name is Rich).

 

He also has a comletely stripped XJ shell sitting on a flatbed, that he's planning on selling to the scrapyard.

 

Jeff

[pingpong]

I am getting ready to pick up another project as is :eek: Trading away a bunch of junk for another piece of junk :nuts: There will be more on this. As of right now I am good on parts, unless... I'll give you a call.

[88swampedmj]

well thanks for the knowledge guys, iam just really paranoind now, soon i may get rid of the 91 for a 00 dodge dakota v8.....i wanna be able to tow my black comanche to wheelin spots

[GirsMJ86]

well whats weird about mine is. at idle its about 30-20.. but when i start it up cold its around 40.. then as the truck warms up its around 40 driving and 30-20 at redlights.. but on the highway it goes down to 30-20 while in 5th gear doin 70 or w/e.. that made me wonder

 

this sounds the same as my 91 HO. so don't worry about it.

 

but i was so use to this thing that i drove a newer s-10 for a day and the oil was around 60-70 and i was worried it would blow on me, found out thats normal for that thing though.

 

Alex