Overheating

My tundra is overheating while pulling my boat at interstate speeds. If I drop back down to 60 it is fine. Any ideas?

I had almost the same thing. I started with cleaning the outside of the radiator. It was a chevy with a few years to it. I was surprise at all the fine black dust from the fins. After it was clean it was ok then. Hope this help alittle.

with out knowing how heavy your boat is,or if you have pulled the boat before with this vehicle,several things come to mind.
restricted cooling fins as mentioned,especially between the radiator and a/c condenser, radiator plugged internally,low coolant level,faulty thermostat,cracked cylinder head just showing up,this one generally includes coolant loss often times with no sign of a leak,cooling fans not coming on due to a bad relay,fuse,sensor,or bad fan motor if applicable.
are you using tow/haul mode with a heavy load? anything different since last time you towed the boat? sorry I cant be of more help without seeing it in person.

Boat is a 17 ft Lund not real heavy. Towed 400 miles 2 weeks ago and no problems. I will start with the radiator cleaning.

As Gary said.

#1 make sure your radiator is free of dust and cottonwood !

#2 make your radiator fan is working properly

JMHO Jeff

What year and engine do you have?

FDR

2000 with 4.7 and 215 thousand

i have the exact same problem with my 2001 Ford Ranger 4.0L. it only overheats when its hot outside and almost exclusively when towing and it will only happen after ive been driving for around 30 min at highway speeds. Ive been dealing with it by turning the heat on full blast and then the temp will go down but its very frustrating and its miserable to drive with the heat on in the summer. I cleaned off the radiotor grill and that did not fix it. next step is to replace the thermostat but ill be watching this thread closely as i need a resolution to this too.

Check for grass, weeds, bugs, etc. between the AC condenser and the radiator. Lots of crud sticks in there and blocks air flow. Another thing that could be the cause with that kind of mileage is the radiator tubes could be limed up with mineral deposits. If that is the case it is best to replace it.

I had a car with limed up radiator once. Had to run the heater in the summer to keep it cool. Replaced radiator to fix.

brad-o wrote:

2000 with 4.7 and 215 thousand

How’s your AC working? I’ve got a 2001 Sequoia, and I was having a problem with the AC at slow/no speeds. The radiator/AC condenser had tons of gunk. Cleaning it out helped a ton.

Check the fan clutch if it has a radiator fan that is belt driven. When the engine is hot the shut it off and grab the fan blade and it should be hard to turn by hand. If its not the clutch is bad.it should be harder to turn when its hot than it is when its cold. And when cleaning the radiator fins hose them out from the engine side out The front .

Replaced the thermostat and did the same run I did on Saturday all good today. I guess the stat would not open to the full position. Thanks for the advice. You guys where way more helpful than the Toyota dealer!

Even my mom is more helpful than the dealer