I just received a phone call from a friend, not on this forum (doesn't do internet), questioning what the correct oil pressure and water temp should be running, going down the highway. He has a 98 U320, M11 with 450 Hp. He said if he is reading the gauges correctly, the water temp is right at 200, and the oil pressure is 30# and drops to around 15 at idle.
He recently bought the coach at FOT, they told him the readings were good, but he has concerns. I turn to the experts. What should they be?
Thanks in advance,
Larry
I have an ISM 450. My coolant runs 175-180 most of the time. About the same for the transmission. Oil pressure is about right and typically will drop some at a stop light.
Roger
I have the 350 and my water is 180, pressure is 50 cold, 40 hot and does not drop below 20 at hot idle. I would be worried with 15 and would consider replacing pump ( but I may be way out of line in my thinking this was not good) Maybe Brett can weigh in on this one.
JohnH
The M11 and ISM engines do not carry as much oil pressure as the ISL and 8.3
You are one of the experts Ron on these things. I learn something all the time.
JohnH
It looks like just under 200 on the gauge but Silverleaf says 180-190. Oil pressure is about 35 and drops to 20 or so under idle. This was the same on both my 320s.
My '99 320 runs at about 180+ and oil pressure about 38 lbs while driving. I have noticed that if head lights are on or running Dash air, it pulls the volts on the chassis batteries down(over time),at least on the gauge, to closer to 12.7-13 volts, and then the oil pressure shows lower and temp shows higher. I understand they are all using same wires and thus loses some.
If I turn off the lights and dash air or others, the shown volts go back up and oil pressure goes back up and Temp comes down. I have checked with Silverleaf and it is a gauge reading issue, not a real issue. Silverleaf actually shows slightly lower Temps and lower oil pressure (about 35 lbs)
Dash volt meter gauge does not reflect voltage at battery. Additional volt meters directly connected to battery will do a better job.
Larry,
Both oil and temp readings are good. Believe it or not 10 psi at idle is acceptable and 30 psi at rated revs is also OK.
Keith
Thanks everyone for the responses. I knew that the answer was a mere click away. I'm trying to convince my friend he can get the same results if he were to join this great group of wisdom. I appreciate all that you all do for my help.
Larry