Archived Overheating

[emyers7918]

Isb 230 To Isb 245 Overheating

SWAPPED MY ISB 230 FOR A ISB 245 AND THE 245 IS OVERHEATING EVEN WITH NO THERMOSTAT. THE 245 ONLY HAS 126 MILES ON IT. THE DEALERZSHIP WRECKED THE TRUCK WHILE DELIVERING IT. BOTH ARE 2001 MODELS. ANY SUGGESTIONS? ALREADY FLUSHED RADIATOR AND BLOCK. NO OIL IN COOLANT OR WATER IN OIL

 

[Alan Reagan]

Is the water pump working? With no thermostat, you should be able to see water movement in the radiator.



Was the thermostat removed to see if that would stop the overheating?

 

[B.G. Smith]

Put the thermostat in a pan of water and heat the water to 180 deg. F and make sure it is operating then put it back in. I don't think you can successfully run the engine without the thermostat as it has a internal bypass for warm up that is closed off by the thermostat when it opens. Most modern day engine water pumps will move the water through the radiator so fast it won't have time to cool if run without thermostat. Is the water boiling or is the temp gage just showing too high? Radiator might be internally plugged or restricted and as always, might have oil fouling on the outside due to the vent line near the right lower corner. bg

 

[emyers7918]

radiator checked out at 95% flow. also tried without thermostat, two new thermostats, still overhaeting. no hydrocarbons or gas in coolant. gonna pull engine oil cooler to see if plugged

 

[B.G. Smith]

Per Alan's question above, I would look at the water pump first, Don't think the oil cooler would cause high temp unless leaking. If this thing was wrecked, the impeller might be off or damaged on the water pump?? bg

 

[Kirwin]

Themostat issue

PUT YOUR THERMOSTAT BACK IN!!! Oo. Oo. When the engine is cold the coolant recirculates using a built in passage in the block that is unblocked with the thermostat in the closed position. Thus without a thermostat, the engine will over heat as the recirculation path is not blocked off when the thermostat opens after the engine comes up to temperature! Thus the water takes the path of least resistance and just recirculates through the block vice going to the radiator. Ensure your thermostat is installed in the correct direction and has a large rubber donut type seal properly seated around it. Ken Irwin

 

[emyers7918]

2nd thermostat and water pump as well. pulled my brothyers thermostat to compare circulation and i have nothing compared to him. we have back flushed everything we can find, to no avail.

 

[Kirwin]

Fan belt routing?

Is it possible that you have a fan belt on wrong? Did you check to make sure the rubber donut seal was installed properly? When you refill the engine with coolant, do you burp out the air to ensure that the block is completely full of coolant? You can disconnect the forward heater supply elbow to get a vent path or remove one of the plugs at the top of the engine. Don't rely on the internal passages to vent all the air out. Other than that, maybe pull the water pump and use a mirror to check if there is something blocking the flow path. Just thinking out loud, but overheating is not usually a problem with these trucks. Ken Irwin

 

[emyers7918]

well i found it!!! B] The head casting was a defect. where the water exits the head into the thermostat housing, the casting was closed off. nothing but a trickle. `found a screw driver that i didnt like much and a pick and a big hammer cause by now i was unhappy. but i got it. thanks for all yalls input