Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 15, 2025 ...

Oil pressure gauge issue.

April 17, 2018, 04:12:13 pm

We had an interesting experience this morning while travelling on I-40 east of Paraje, NM. It was early and I had the headlights on. The oil pressure has consistantly been running at 30 psi while on the highway. This morning when the headlights were on the gauge read 20 psi. The coolant temp gauge also gave an odd reading, only higher by 10 degrees. The ambient temperature was 48 degrees. The tach and all other gauges read as normal. I pulled into a service area, turned off the headlights and shut it down. All seemed well in the engine bay. Fluids checked as normal for the temp we were at. By that time the sun was up, we started up and everything went to normal. The oil pressure gauge and the coolant temp back to normal as well. Voltage from alternator when headlights were on was 13.2-13.3. When off 13.5. Any suggestions? Thanks for any help.

Quote Selected

Re: Oil pressure gauge issue.

Reply #1 – April 17, 2018, 04:22:52 pm

The electric gauges are sometimes voltage sensitive. I had the same issue and may still have. I only read the VSMpc now and when I first put it in the dash gauges fluctuated but not the VSMpc. I will see if it is still fluctuating in June when I use it again.

Quote Selected

Re: Oil pressure gauge issue.

Reply #2 – April 17, 2018, 04:38:18 pm

Check for a poor ground for the gauges.  Certainly would not hurt to just add one.

Quote Selected

Re: Oil pressure gauge issue.

Reply #3 – April 17, 2018, 06:40:07 pm

Mine does that when you turn on the head lights temp goes up op goes down. I chased it around checking grounds and so on. I just rely on VMspec now.

Quote Selected

Re: Oil pressure gauge issue.

Reply #4 – April 17, 2018, 07:00:46 pm

Check grounds and look through your schematic for a voltage stabilizer  that feeds the senders. 

Quote Selected

Re: Oil pressure gauge issue.

Reply #5 – April 18, 2018, 08:34:57 am

Mine does the same thing.  Extra grounds haven't helped.  I live with this behavior.

Quote Selected

Re: Oil pressure gauge issue.

Reply #6 – April 18, 2018, 08:40:47 am

The schematic diagram for my 1997 U270 shows no voltage stabilizer, so your readings are voltage-dependent. You could add a voltage stabilizer for the gauges, but it adds complexity.

Quote Selected

Re: Oil pressure gauge issue.

Reply #7 – April 18, 2018, 09:33:04 am

I have had the same issue for years. When headlights on, or sometimes the AC, the oil pressure gauge goes down, temperature gauge goes up and volts shown go down. When I check with SilverLeaf levels are normal.
I concur it is a voltage issue, too much on same circuit?
I am used to it and so would not worry about it.
 

Quote Selected

Re: Oil pressure gauge issue.

Reply #8 – April 18, 2018, 07:35:46 pm

Thank you to everyone who took the time to respond. For the time being I will ignore this issue. It appears that a VMSpc is in my future.

Quote Selected

Re: Oil pressure gauge issue.

Reply #9 – April 18, 2018, 07:51:36 pm

Does your oil always run in the 30's or is it just when this problem in happening? Mine is always 55-57 when at hiway speeds.

Quote Selected

Re: Oil pressure gauge issue.

Reply #10 – April 18, 2018, 08:11:56 pm

I believe our M-11's have lower oil pressure I have never seen 55 psi. except when cold.

Quote Selected