Overheating issues

[shootist]

https://www.walmart.com/ip/COMBUSTIO...IESEL/16550935
This will check for worst case scenario. Head gasket or cylinder liner leaks.

[super_rep]

Check your hydraulic pump. I just had a similar experience with our coach. Replaced thermostat-no effect; replaced engine water pump-no effect; flushed radiator-no effect; finally found that the PTO shaft and hydraulic pump shaft coupling had sheared all the splines from both the PTO shaft and pump shaft. Coupling was just spinning and not turning the hydraulic pump fast enough to drive the fan hydraulic motor at full speed.

I had to replace both the PTO and hydraulic pump. Problem solved. It turns out that this has happened to others and is a weak point in the design.

Send me your phone # in a PM and I'll call you and give all the details and sources of the parts. Monaco doesn't have any information on these parts for older coaches.

[pflightnut]

@super_rep @NHagar --- what's the latest? PTO and/or hydraulic pump? Solved? Or not?

[wolfe10]

Lack of lubrication on a PTO-driven hydraulic pump has been a well-known issue for over a decade.


If you have a PTO-driven hydraulic pump, you need to either grease it annually or convert to the "wet kit" that lubes it from the transmission, or, you are correct, suffer a very expensive failure.

[FrankenRV]

Is there something else that may be causing this other than radiator, fan, and water pump? For example, a transmission problem or dragging brake?

When the engine is running, what does your IR thermometer show when you point it at various parts, like the radiator, water pump, coolant intake hose connection, and coolant discharge connection?

Do you have a transmission temperature gauge? If so, anything abnormal?

After you drive it for a while, what does your IR thermometer show when you point it at the brake drums?

[SteveD]

At that age, even if only those miles, it's past time to pull the rad and have it 'rodded out'. Had similar overheating issues on my '94 HR couple years ago. Took the rad to a shop and WATCHED them rod it out. It seemed to be about 75+% CLOGGED. After rod out and flush, engine now runs great and an AMAZING difference in the ambient temperature around the running engine in the summer... especially in the bed, which is immediately above the engine.


Steve

[AirBossdavid]

Have you checked that the temp gauge is accurate? It is possible (however improbable) that when it overheated it threw the sender or gauge out of calibration. Easy to check, use a laser thermometer thing on the sending unit to check.

I had this issue on a transmission where it suddenly started running 20 deg hotter than normal and the sender was failing. A bad gauge could do it too.

If you have not found it yet a good check before taking to someone expensive!