236k miles on this old girl
heating issues at idle climbs up to 240 but doesnt go passed it
Replaced water pump, coolant, clutch fan(severe Duty), and radiator.
A/c and heater both work
did the spark plugs all plugs look good no indication of coolant.
Imma replaced thermostat tomorrow.
can anyone help?

 

After the T stat, make sure its bled properly. Does it lose any coolant? Have the LIM gaskets been done?

George

 

LIM? It doesn't lose coolant.

 

All of our trucks eventually need to have the lower intake manifold gaskets replaced. They start leaking and cause oil to mix with coolant. Glad your not losing coolant. If you have a scanner with live data capability does the scanner temp agree with the dash temp at 240F?


George

 

Ooh hopefully it has been done before, havent had the truck that long. But yeah I was considering the temp was reading falsely. I currently dont have a scanner that does live data but imma get my buddy's aural tomorrow and see, after I do the thermostat

 

did the thermostat(195f), jacked up the front end to bleed the system did that's for about 30 minutes. But still idle at 230. Heater isnt working anymore the heater hoses are warm. Checked live data with an autel scanner and the temp guage is reading property.
what now? Did i get a bad thermostat?

 

What color is the coolant, possible someone mixed green w/ Dexcool and gummed up the system? Not to sound like a broken record but vacuum controls HVAC and those hoses are often shot.

My ignorance on the scanner temp reading but what you determined is that the dash gauge is accurately displaying what the temp sensor is putting out. Isn't that all the scanner does too? In other words the scanner can only display what the sensor is telling it so is it possible the temp sensor is bad?

What is the temp rise from running to idle? It is true it should be able to hold a pretty steady temp.

 

Given everything that you have replaced And your new no heat problem I think your still not bled and/or you have a plugged heater core. Try flushing the heater core both ways with a garden hose at partial pressure. Then rebleed and check.


George

 

I flushed the whole system plus the heater core and boom!!!
idling for about 20 minutes 195-205. Lot of the clay **** came out so I removed the expansion tank also and flushed it out but

Thank you everyone! For the help.
will update if any issues pop up

 

Chance then that someone mixed an incompatible coolant w/ Dexcool at some point. That or its just and old beast! Either way good news.