TRUCK OVERHEATS WHILE DRIVING BUT DOES NOT WHILE IDLING

Is the radiator fan coming on when the engine reaches 220 degrees ? ?

If the exhaust converter is worn out & blocked, it
overheats & does all sorts of damage


Did you not leave it & have them make the necessary
repairs?

When any vehicle goes over 215 you shut it off & step out,
& don't use it until it is repaired, even if you need a tow truck
& a taxi cab

You overheated it 3 times,3 times Really Why is that?

Sounds like the front of the radiator or A/C condenser is clogged up...take a water hose and try to clean any debre from the front, so air can pass freely...

At idling speed an engine does build up a lot of heat and the cooling fan will kick in. In slow moving traffic or traffic jams the temperature gauge can touch the red - particularly on hot days. The reason it cools down when you start moving is because of the air flow through the radiator.

Presumably there are no leaks from the cooling system otherwise you would have mentioned it. In normal circumstances the fan will not be running as you are driving at speed, as the air-flow through the radiator is sufficient to cool things. The fan only kicks in to get rid of excess heat - and this usually occurs at idling speed or after you have parked the car.

If the fan is running all the time as you drive, this points to either a fault in the fan switch, or the car is running too hot. presumably in normal driving the fan isn't running and the temperature gauge reads normal?

It is common - in stationary traffic many cars overheat (particularly big engined models) try to stall and 'cut out'. Restarting can be difficult until the engine cools down.

Is your car overheating in normal driving conditions or just at idle speed? Overheating in normal driving conditions can be caused by things like a failing water pump, blocked radiator, collapsed hose, faulty thermostat or, in the worst case scenario, cylinder head problems.

Overheating at idling speed is 'common'. Check your coolant level. If your car isn't using/losing coolant then there probably is no major problem. You can flush out the cooling system and refill with new coolant - and also check your radiator. Are the cooling fins crumbling with age? Or maybe they're partly clogged with insects and debris from the road? A blast with a hosepipe wil sort that out ..

The question is how much does your car overheat in normal driving? If it doesn't .. it appears as though you have nothing to worry about as such. Most cars have 2 speed fans... the 2nd faster stage kicks in at some point dependant on engine temperature. Perfectly normal.

The most common overheating problem with the Northstar engine is a blocked purge line. It's job is to purge air out of the cooling system.
There is a small diameter hose coming from near the top of the coolant tank,this is the purge line.
With the engine idling,pull the purge line from the tank,if there is no coolant flow from this small hose,it is blocked and this will cause overheating.If the hose is clear, check for blockage at the nipple on the tank.Or trace the hose back until you find the blockage.The hose goes in to the engine to a crossover and comes out the other side to near the thermostat housing,the blockage may be there.

Sounds like your electric fan is not working. No air flow when sitting, the fan is not needed when driving. If you turn on the ac most cars will have the fan come on until ac is turned off. If your fan cames on the you can use this option to cool the car until you can fix the real proplem.

chances are that it isnt your thermostat, check to see if your coolant fan is turning on when engine reaches operating temperature. if it does turn on then i would suggest to check for dust/dirt in between your rad and a/c condensor. if it is dirty in between clean it out with a garden hose and you should be good to go

Not good. I saw nothing about the fan being checked?

The cooling fans will not come on until 225 degrees. Normal temp is around 199-215. Sitting still in traffic most will inch up around 220 or so. When you turn ac on it turns the fans on and may cool down engine, Check fan operation.

Hi my name is Allen!
The first thing you need to do is check for coolant leaks, I suggest this because you seen steam coming from under the hood. Various places to check would be the radiator, hoses, water pump, heater core, head gaskets, freeze-plugs. Check the level of coolant in the radiator, but only after the engine has had time to cool-down because you could be seriously burnt by removing the cap if it has not cooled.

If the radiator is full then other causes could be; the radiator fan not working properly, the thermostat could be sticking closed, the system could be restricted not allowing coolant flow unless driving vehicle, and the water pump could be defective. These are just a few possible causes!

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