Why is it sometimes when my truck idles or is driving in stop and go traffic it overheats?

Question

For the record, I recently replaced the thermostat and flushed out the cooling system. It doesn't seem to boil over all the time. In fact, sometimes I think it has no rhyme nor reason to it, but it does do it more after idling a while or when driving in stop and go city traffic. The truck is a 1991 Ford F-250, automatic, 2-wheel drive, with the 4.9 Litre inline 6 cyl. engine. Thanks in advance for any input.

Answer 1

Fan clutch probably getting ready to go out bout 30-40 bucks at a junk yard.

Answer 2

at the same time as coolant in an engine exceed 260 tiers, it starts to boil. The pressure led to with the help of coolant transforming into steam will reason the radiator to boil over. There are 3 a chance motives. a million. you've a coolant leak that has led for your cooling equipment to free coolant and the shortcoming of sufficient coolant is why the engine overheated. to study for a coolant leak, (in case you may't see it) you may ought to have the cooling equipment pressure examined. A pressure try may be performed at your community storage for extremely little fee. A pressure try will pressurize the cooling equipment which will make leaks that won't be able to extremely be seen, take position. 2. you've a restriction interior the cooling equipment which includes a stuck thermostat or a plugged radiator. Coolant that doesn't bypass to the radiator because it may won't be able to launch the nice and cozy temperature it has amassed from the engine. 3. you've constrained air bypass over the radiator. A defective fan grab or debris interior the radiator fin may reason lack of air bypass over the radiator. so a procedures as fee is in touch, once you've a leak, a hose is minor, a water pump or radiator isn't. one element is for confident, a overheating difficulty can damage the engine that's extremely severe priced. You mechanic can carry out a "chemical block try" to study for the presence of exhaust gases interior the radiator. Exhaust gases interior the radiator are undesirable because they arrive from a blown head gasket or cracked cylinder head. are you able to assert ka ching?

Answer 3

Sounds like your radiator is plugged. When the truck is warm run your hand over it and see if you have hot and cold spots. Make sure if the truck has an electric fan you do not put your hand near it as they can come on when the truck is off,

Answer 4

if it has an electric fan it might not be coming on when it is supposed to, that would be the temperature switch, the water pump could be going bad, or the radiator might be plugged.

Answer 5

Possibly your cooling fan.

Answer 6

have you checked to be sure the cooling fan is properly working?

Answer 7

not enough airflow across the radiator.