Ericson 30+ and Universal M18 - Over heating

[vincentshine]

Hi all,

End of season problems. After a failed fuel pump and replacement, the engine was running pretty good for a solid hour in idle. the next day, ran intermittently but then overheated. As part of my winterizing efforts, I drained the water heater tank and bypassed in order to winterize the water system. This was prior to running the engine and it overheating.

Is there any reason the empty water heater could cause the engine to overheat? I'm thinking that or now the thermostat is bad.

Thanks all!

 

[Timsb]

I have motored with an empty water tank without having a problem - I have an m25xp with a 3 inch heat exchanger. Was it overheating in the water or in the yard during winterization? Regardless, was water coming out the exhaust?

 

[vincentshine]

I have motored with an empty water tank without having a problem - I have an m25xp with a 3 inch heat exchanger. Was it overheating in the water or in the yard during winterization? Regardless, was water coming out the exhaust?

Makes since. I really don't think the hot water tank has an impact on the engine coolant. This was in the water prior to winterizing. Exhaust water was coming out the back. It reached about 230 F at the thermostat. I thinking the thermostate, or blockage. She's out of the water now so will be a spring project. I'll be going through all the systems to figure this out.

Thanks, Vincent

 

[Christian Williams]

Is any part of your water heater or heat exchanger above the filler cap? (If so, you'd have a remote or secondary expansion tank.)

I ask because air can get into cooling systems as well as fuel systems. I'd first make sure that the replumbing didn't cause an air bubble, which can result in instant overheating.

If the hose runs to the heat exchanger seem OK, I would pull the end gaskets off the HX and check for ancient pieces of zinc or impeller or glop or scale. It's easy to do--once you figure out how to reach it.

But if it ran OK before, probably air in the system.

Also, a water heater hooked up to the closed cooling system works by drawing off engine heat. Disconnecting it might reveal an overstressed HX.