I have a 94 yota 4wd v6 that is overheating after driving 70mph for about 10 minutes. I had the recalled head gasket changed about 7 years ago. Then I had the water pump and thermostat changed. The fan clutch seems ok. I do not have water in my oil and I flushed my radiator. I noticed that it burns more gas and is lacking in power. It wont overheat just running in the driveway but does on the interstate. I noticed the flow in the radiator seems slow. It boils over after driving and I am praying that its not the the head gasket. Could it possibly be the radiator is partially clogged? When I lifted the hood the exhaust was glowing red. I sure wish I never would have let the yota dealership change the Head gaskets when it was running fine. It never ran the same since. The transmission went out the day after the head gasket change and they replaced that also. With only 123,000 miles it should have had a longer life.

 

Check the thermostat!! When it starts to get hot does going to full hot on your heater control help?

 

yes turning the heater on helps

 

Pull the thermostat out of the housing, drain your radiator and flush it out with a garden hose and try it.

 

yeah i tried that also. I am just praying that it is the radiator

 

Overheating at high speeds is often the radiator. Mine did that and a new 3-row (for 22RE) radiator did the trick.

 

I hope your right. Can you tell by filling the radiator and pulling the bottom hose, and if it pours out without burping?

 

One option, look inside and see if you can see heavy deposits inside the cooling passages. Top filler can see the center, bottom hose and you can look across the bottom. Or run until hot and spray front of rad w/ water and see if it evaporates evenly or if there are spots that stay wet (as in no coolant flow there so no heat).

 

thanks for the info. I will try that and pray thats it.

 

I did find some rtv floating in the radiator but if it were the radiator shouldnt it overheat while running in the driveway v/s doing 70 in cold weather? I guess rtv was from the water pump change about 10,000 miles ago. That may have clogged something that the water hose isnt gonna flush. Thanks for all your help

 

While idling the radiator has less flow going through it, giving the fan more time to cool the coolant as it is in there longer. At highway speed the coolant going faster through the radiator amplifies a clogged radiator. Try power flushing first, the shop I work at has a machine that uses compressed air and water. I would also replace the t-stat at the same time as overheating tends to damage the spring. If it still overheats it's time for a new radiator.
Also check the fins for any sign of corrosion

 

Thanks that is exactly what i wanted to hear. I will be very happy if thats the problem.