What's the Correct Oil pressure?

[The_Handier_Man1]

From: Derrek  (Original Message)
Sent: 6/12/2003 11:06 AM

As I recall the pressure gauge in my Brave showed the oil pressure between 55-60 psi when the engine was cold and around 40 psi with the engine at operating temperature. I left the factory gauges in place when I installed the aftermarket gauges and the factory oil pressure gauge would read about 25% of the normal range with the aftermarket gauge reading 40 psi. If you can understand that. Kinda hard to describe LOL!!! This of course was with the 318 engine.

I installed a digital gauges in my Apollo and the oil pressure is about 75 psi when the engine is cold and around 40 psi at operating temp. This is with the 440 engine.

In the service manual it should list maximum and minimum specs for oil pressure. May be listed under specs in the chapter entitled engine, but I am not sure.



From: denison
Sent: 6/12/2003 12:59 PM

When using 20W50 in the South U.S in summer, my oil pressure at a hot -250f- idle would be 25 psi or so, and using 10W30 it would be slightly less than 10 psi. At highway speeds, hot, the 20W50 oil gave me a 50-55 psi reading, the 10W40 oil gave me a 30-40 psi reading. I would advise making a note of your oil pressure when fully warmed up, i.e. after an hours drive, both at highway rpm, and at an idle. Then keep track of how it changes over the miles. Mine has been the same for 40k miles. If you see it drop much, try a new oil filter. I think these engines are not particular about what oil you have in them. denison 



From: denison
Sent: 6/12/2003 4:06 PM

Going by the original Dodge gauge - when I start it up cold it goes about 2/3rds of the way across the bracketed line that is meant to indicate the normal pressures. Once warmed up it will be to the right of center when on the highway, though with the 10w40 it might barely be to the right of center, going 55mph. At a cold idle it stays near the center, and when the oil is really warm, it droops down to the left end of the bracketed line with 10W40, less than 1/4th the way across the gauge, maybe more like 1/5th. With the 20W50 oil, at a hot idle it would be at least 1/3rd of the way up from the left side of the gauge. I don't think the Dodge gauges are very consistent, from one RV to another, nor linear. They do a good job of telling you that there is some oil pressure. One day mine didn't move at all. I removed the engine cover, and began to unscrew the sending unit, and oil began to ooze out, so I knew I still had pressure. It just needed a new sending unit. A vacuum gauge would work just the same on an engine powered by l.p. gas - and would show you how hard your engine is working.  denison



From: dave76Chieftain
Sent: 6/12/2003 4:40 PM

Just for reference,
73 - 75 Dodge Motorhome book says 8 lbs at idle and 30-80 lbs pressure at 2000 RPM for the 318, 413 and 440 engines.  The 30-80 value would naturally take wear into account and therefore covers a wide range.

Dave