03 4.6 overheating problems

[robboman48]

Just had cooling system flushed, new radiator cap, new thermostat, pressure tested (OK), new trans fluid with pan dropped and filter cleaned, new synthetic valvoline oil. No leakage from water pump, 50/50 mix, and cooling system is circulating. Car overheats in 3 miles and can't be driven. Runs great, starts immediately, good gas mileage (24-25 on hwy).

Any ideas.

[rhandwor]

I would suspect a plugged radiator. A radiator shop will check the anti freeze for gas from a problem with a head gasket. Look at the top and bottom of the radiator for blockage.

[fleettech]

could be a dead fan or bad relay big air bubble in cooling system.

[Blue)(Fusion]

I doubt it would be the fan. If the car was able to get to highway speeds it should remain about 192 degrees then, and it still would take a long time to overheat at idle with no fan.

The radiator may be blocked or the thermostat may not be functioning properly. Feel the upper radiator hose to see if it gets warm as the engine gets to the normal operating temperature. If it does not warm up, the thermostat is likely the issue, preventing water to flow from the engine to the radiator.

[ronaldk]

Check to make sure hoses (Mostly bottom rad hose) are not colapsing. If it feels soft and mushy replace

[din365]

did you put one of those 195 thermostats in there?

If so, throw that thing out, and buy a 180. My 88 LTD crown victoria went through two of those bastards in two months, because they are crappy thermostats. I almost cooked the head gaskets the second time because the second one was defective.

What also causes overheating is the head gaskets being far gone, and oil being pumped into your cooling system, and vice versa. Check your exhaust. does it push out plumes of white, damp exhaust? does your coolant have black or brown stuff floating on top? Does your oil look milky?

If you answered yes to these, then I got some bad news for you.....

your head gaskets are gone!

[Stale Trooper]

Originally Posted by robboman48

Just had cooling system flushed, new radiator cap, new thermostat, pressure tested (OK), new trans fluid with pan dropped and filter cleaned, new synthetic valvoline oil. No leakage from water pump, 50/50 mix, and cooling system is circulating. Car overheats in 3 miles and can't be driven. Runs great, starts immediately, good gas mileage (24-25 on hwy).

Any ideas.

Did you (or your mechanic) 'BURP' the cooling system? If it isn't burped (remove the excess air), that can cause overheating problems as you've described.
This happens due to the routing of the upper radiator hose, which ends up higher than the top of the radiator and/or the fill tank. You can usually burp it by squeezing the upper hose a few times, while keeping the fill tank at the "Full Cold" or appropriate level if it's warmed up.
You may need to go thru this procedure a few times, to get all of the air out of the system.
Don't do it when the engine is hot from driving, hot water tends to make your face really ugly!
Good Luck!