803a running @ 130 degrees F after 1 hour+ with no load?

[Farmitall]

Seems it doesn't want to come up to anything higher than 130 degrees.

Exhaust gasses are hot, can't hold a hand above it 6 inches for more than a second or two.

I drained the coolant, removed both radiator hoses and cleaned all the connections of corrosion and replaced the lower hose. I used a very light coating of Indian Head gasket shellac on the inside of each hose end. No leaks.

Filled the system 50/50 water and Prestone anti freeze. Started the set and let it run for a little over an hour and it just won't get any hotter.

Any ideas? Thermostat stuck open maybe?

 

[kloppk]

Could be a bad Temp Sensor Or Temp.
Can you check coolant temp by another means?

 

[justacitizen]

Could be a bad Temp Sensor Or Temp.

Can you check coolant temp by another means?

beat me to it. are you sure your gauge is correct???

 

[Farmitall]

beat me to it. are you sure your gauge is correct???

Yes pretty sure the gauge is working ok. The hoses are not too hot to hold onto so its running pretty cool. Much cooler than it should be.

I don't have any other means to check the coolant temp other than my hands which should not be able to hold onto a properly up to temp engine.

 

[pjwest03]

If you trust the reading, it's possible that the thermostat is stuck. You also need to remember that these things have cooling systems suitable for high altitude and high temp climates. It will need a load to truly get hot, particularly in cool weather.

For the future, temp guns are under $20 these days and darn handy around all manner of machinery.

 

[Farmitall]

If you trust the reading, it's possible that the thermostat is stuck. You also need to remember that these things have cooling systems suitable for high altitude and high temp climates. It will need a load to truly get hot, particularly in cool weather.

For the future, temp guns are under $20 these days and darn handy around all manner of machinery.

Thanks for the reminder, I forgot about that!. I have a laser type temp gun and didn't even think of it. I use it to monitor the stack temp on my wood stove periodically. Will get it out tomorrow and see what the input of the radiator temp is after an hour running time.

I'm also almost finished with my load bank so this is motivation to finish and hook it up and see the difference it makes.

 

[gimpyrobb]

So is this just running,not powering a load?

 

[Farmitall]

So is this just running,not powering a load?

Yes, no load applied.

I would think that it should be running at least around 160 F even with no load. Somethings a miss.

 

[Zed254]

I've got a 165F thermostat in mine. I noticed that the one I took out was 190F so a good amount of variability there. KY has been kind of cool recently.....55F ambient? Might be accurate reading......

 

[csheath]

You don't mention inspecting the thermostat.

I put new hoses on mine and did a visual inspection of the thermostat. Mine had a 180 degree thermostat that looks new so I reinstalled it. Running under a 40 amp load my gauge reads right under 180. Shooting the thermostat housing with an IR thermometer verifies my gauge reading.

If your thermometer coincides with the gauge you probably need a thermostat.

 

[jamawieb]

Did you by chance look inside the thermostat housing to make sure a thermostat was in it? I've had a few where they removed them and ran the same temperatures as yours. You can get a new thermostat from any parts store (Murray ultra 15358 with gasket 2138 ).

 

[Hard Head]

I have had pieces of hose springs stuck in the thermostat. Also in the water pump and in the radiator connections.

 

[Farmitall]

I have had pieces of hose springs stuck in the thermostat. Also in the water pump and in the radiator connections.

The hose springs in both my hoses were very much dissolved. I replaced the lower hose with a new one and removed the remnants of the spring from the upper hose and cleaned and rinsed it out as best I could then reassembled.

I guess I'll have to pull the thermostat housing and see if the thermostat is obstructed from closing. Probably time to back flush the entire system while its drained down. One thing leads to another, and another and another.

 

[Farmitall]

Did you by chance look inside the thermostat housing to make sure a thermostat was in it? I've had a few where they removed them and ran the same temperatures as yours. You can get a new thermostat from any parts store (Murray ultra 15358 with gasket 2138 ).

Thanks, that saved me from digging up that thread with the info.

 

[Bmxenbrett]

What was the outside air temp? These things wont heat up when its cold. If it real cold -5* mine would only get to 130*.
Did you feel the hoses? Temp difference?

 

[Farmitall]

What was the outside air temp? These things wont heat up when its cold. If it real cold -5* mine would only get to 130*.
Did you feel the hoses? Temp difference?

Outside temp was in the 50's. Both hoses felt about equally hot(warm really) so I think the coolant was just free flowing causing the set to run at a minimal temperature. That would indicate an open thermostat.

Its pouring down rain here all day so it'll have to wait for another day.

 

[Bmxenbrett]

Load it up and see what you see. An open thermostat can actualy cause it to overheat. Coolant spends less time in the rad.

 

[Farmitall]

Load it up and see what you see. An open thermostat can actualy cause it to overheat. Coolant spends less time in the rad.

I think you got it backwards. The thermostat is to keep the coolant in the engine to come up to temperature. That's why you see diesel trucks with zippered covers over their radiators to reduce air flow and keep the engine warmer as they drive.

A diesel with an open flowing cooling system will run at minimum temperature. It would take an awful long time to overheat with no thermostat.

 

[DieselAddict]

Load it up and see what you see. An open thermostat can actualy cause it to overheat. Coolant spends less time in the rad.

I think you got it backwards. The thermostat is to keep the coolant in the engine to come up to temperature. That's why you see diesel trucks with zippered covers over their radiators to reduce air flow and keep the engine warmer as they drive.

A diesel with an open flowing cooling system will run at minimum temperature. It would take an awful long time to overheat with no thermostat.

You both are right. If the thermostat is stuck partially open it will run cold at light loads and overheat under heavy loads.

Personally I would inspect the thermostat and rule it out as the problem before running the set more. But thats me.

 

[Farmitall]

You both are right. If the thermostat is stuck partially open it will run cold at light loads and overheat under heavy loads.

Personally I would inspect the thermostat and rule it out as the problem before running the set more. But thats me.

I'm convinced its the thermostat and will not run it until its changed.