Oil pressure

[chusansail]

Lost oil pressure on lehman120. Alarm and gauge
After about 15 mins started engine ran for 6hrsno problems.and continues to run. Any ideas.

 

[Comodave]

Welcome aboard. Maybe a loose connection or corrosion on a connection. Talk to Brian at American Diesel. He is the man when it comes to Lehmans. 804-435-3107

 

[SoWhat]

If the engine continued to run for 6 hours then clearly the oil pump is good.
If both alarm and gauge worked then culprit would be a bad sender or as previously mentioned loose or corroded connections.

Low oil pressure and increasing temperature would be a red flag. If Temp gauge is erratic or intermittent I would dig out the multimeter and check it. The sender resistance will change with pressure so it's a quick and simple check.

 

[Nomad Willy]

There may be a leak.
Did you check your bilge for oil?

 

[Comodave]

Maybe put a mechanical pressure gauge on it and see what it is actually doing.

 

[rgano]

I have seen a mechanical gauge connection on that engine at the connection tree where the low oil alarm switch and the oil pressure gauge sender are mounted.

 

[Pete Meisinger]

I second the idea for a mechanical gauge. It does sound like a sending unit problem. It was a "gutsy" move to start the engine up again and run it for 6 hours without knowing if there was any pressure.

You could have removed the valve cover (it's a less than 5 minute job), fired up the engine and checked for oil "spurts" on the rockers. Don't expect much though, these engines send very little oil up to the valve train.

pete

 

[catalinajack]

I have seen a mechanical gauge connection on that engine at the connection tree where the low oil alarm switch and the oil pressure gauge sender are mounted.

On my FL120 the alarm sender and the pressure sender are threaded into separate ports and are separately wired to the gauge and the alarm circuit. An alarm and no pressure on the gauge at the same time would tell me that there was a problem. I suppose corrosion could be the problem but simultaneously? If it were I, I would install a mechanical gauge using a STEEL run tee fitting either at the alarm port or the gauge port. In fact, that is a pretty good idea regardless.