Coolant Temperature

Golden_HVAC wrote:
A lot of fuel injected engines require a temperature of 180F to get out of the enriched "Choke on" setting, and get better mileage once above 180F. They are designed to have the thermostat recirculate the warm coolant back into the engine until it reaches 195F, then some will go into the radiator to get cooled off. After reaching 200, more goes into the radiator, and by 205 the maximum amount of coolant should be going into the radiator.

However as stated above, you can run 240F in some cars without overheating, it will be in the middle of "Normal" at 240, that is how that type of car works to get the best emmissions readings. Water at 15 PSI will not boil at 250F, and by using a mixture of anti-freese and water, the boiling point can exceed 280F when the pressure is high enough.

Your overheating issues can be because of the thermostat missing, and not slowing the coolant enough for adaquate heat transfer. My recommendation is the proper truck thermostat for your application. Your thermostat might be a larger internal diameter than a 454 gas car engine thermostat, even though they both fit under the same thermostat housing cover. Get one at Napa, or your local GMC dealer, they sell higher than average quality parts.

Fred.

X2

If your overheating with the thermostat in, you have another issue. Replace it with a new one and allow the system to work as designed or take it in for repairs. Your making the issue worse by removing the thermostat as now it temp max is reduced.

JD3rd wrote:
My 1987 Class A Rockwood RV coolant temperature range is 160 to 200 degrees. Is this a normal temperature range for the motor home? During the summer months, I remove the thermostat. This rv has a 454 chevy engine.

Put it back in and let the cooling system do its job.

A lot of fuel injected engines require a temperature of 180F to get out of the enriched "Choke on" setting, and get better mileage once above 180F. They are designed to have the thermostat recirculate the warm coolant back into the engine until it reaches 195F, then some will go into the radiator to get cooled off. After reaching 200, more goes into the radiator, and by 205 the maximum amount of coolant should be going into the radiator.

However as stated above, you can run 240F in some cars without overheating, it will be in the middle of "Normal" at 240, that is how that type of car works to get the best emmissions readings. Water at 15 PSI will not boil at 250F, and by using a mixture of anti-freese and water, the boiling point can exceed 280F when the pressure is high enough.

Your overheating issues can be because of the thermostat missing, and not slowing the coolant enough for adaquate heat transfer. My recommendation is the proper truck thermostat for your application. Your thermostat might be a larger internal diameter than a 454 gas car engine thermostat, even though they both fit under the same thermostat housing cover. Get one at Napa, or your local GMC dealer, they sell higher than average quality parts.

Fred.

Some parts of pollution control systems require temps of 195. Mine runs at that temp and cycles open and closed. Seems normal to me.

Using an after market gauge monitoring temp on the left head I see consistent readings of 220 degrees just cruising down the road. I would suspect that if I were monitoring water temp at the thermostat housing outside the engine I'd see perhaps 205+ at least. So it sort of depends on where your gauge is measuring the water temperature. A pressurized water system can run with water temps up over 250. I've never boiled off my system pulling some long, steep grades out here in the west.

Why do you remove the t-stat?
Coolants job is to absorb heat from engine........flow has to be controlled in order to absorb that heat. That's why they come in different degree settings.

Removing the t-stat allows the coolant to flow unrestricted and doesn't allow for proper heat transfer. And an inefficient engine.

200*F is a very normal temp..........temps over 210/220*F would be a concern.