My engine as far as know has never overheated. I replaced the OE radiator in the summer and had no issues, I replaced it because of leaking problems.

Last week I was driving up a small mountain and noticed the water temp rising to over 210F with outside temp around 55. I am afraid that in the summer my truck will get much hotter, maybe an OH problem to climb for a long period. Should I have bought a better quality radiator? the replacement is aluminum/plastic from NAPA. Or could there be something else slowing the circulation?

 

What motor? How is the fan clutch? Is there any resistance from it when you turn it by hand? Sounds like it is not pulling enough air through the radiator fins. Did you use Toyota red coolant and distilled water? Did you flush the cooling system when you changed the radiator? Were you using the heater when this was happening? Have you pressure tested the cooling system to check for any leaks? IMO 210 under load is not terrible.

 

'88 3vze I didn't professionally flush or pressure test. I did fill with water ran it till hot 3 times and never had to add water it has been 4 months. My shroud is in bad shape.

 

Just water? What about coolant? The shroud is also important to keep the air flow correctly cooling the system.

 

lol yes the green stuff 50/50

 

Yeah 210 is not bad for a load. I am concerned in hotter weather it may overheat.

 

As 93toy said - the shroud is important, and check the fan.

 

When was the last time you looked at the water pump?

As my 5vz-fe timing belt was getting up in mileage, it began slipping on the water pump pulley and the temp began creeping up to 204-206 range. Changed belt and pump....temp now runs 191-193. Even going up Mt. Hood, from sea level to 5,500' I only hit 196.

 

Maybe a water pump loses volume over time. I might consider doing this.

 

Yes, they can leak if the gasket or the pump is failing. Pull the front cover and take a look.

The timing belt threads will give you pictures of leaky pumps with pink (Toyota coolant) or green crust on them.