I replaced everything last year. Rad, factory t-stat, water pump, belts, and hoses. It is not losing coolant.

It runs about a fourth way up on t-gauge in town, but on the highway, once I go over 60 it runs half way on t-gauge, and from there, the faster I drive the higher the temp climbs. That is with the A/C off. I have burped the system, and running proper ratio of anti-freeze.

I have not flushed the block, and timing is perfect.

I have not tried running without t-stat yet.

Any ideas?

 

Sounds like you still might have air in their somewhere. Possibly.
Dumb question...does your clutch fan kick on? Is rad. blocked by debris?

 

clutch fan works, and rad is very clean.

 

Might want to try and jack the front of the truck up and see if you can get some air out, if any.

Id start there first.

 

i drove it up on my ramps, and pumped the lower rad hose no air.

 

Hmm....well i dont know.

 

tune up- timing and idle set properly, valves adjusted, etc.

 

valves ajusted last summer, and timing is dead on.

 

okay. so temps are fine (relatively) when driving around town, but on the highway, temps climb.

You've got a new water pump?
You've got a new thermostat?
You've got a new radiator?

You have a 22re, no? (It doesn't say in your sig whether 22re or 3vze, but you mention timing chain so I'm guessing 22re.)

You've replaced all the radiator hoses. Does that mean you've replaced BOTH lower radiator hoses?

 

Abe, that is exactly right. if i drive 60 it runs half way on t-gauge, as the speed increases so does the temp. all the hoses large and small.

 

Higher vehicle speeds tend to eliminate the fan and fan clutch from the equation since the ram effect can move more air than the fan can.

Overall, it sounds like the radiator is bumping against its cooling capability... but, what is the rating on the thermostat? Do you have the radiator shroud installed? When it starts getting hot does turning the heater on hot and fan on high help?

 

T-stat is from the dealer, all 14 bucks worth. fan shroud is installed, but have not tried the heater trick. I HATE a vehicle that does not run cool.

 

i am going to ohm the temp sensor tomorrow.

 

You might have a bad temperature gauge sending unit, I had one go bad and the temp gauge would always read just above cold when the engine temp was normal. I replaced the sending unit and everything was normal again, so this might be something worth looking into.

 

yep. if the gauge is wrong, nothing else will ever be right.

 

yes, as far as i know it is original. check it before church in the morning.

 

Checked the timing and t-stat today and both were fine. She wanted to over heat sitting in the drive way, but put a fan blowing into the radiator, and the temp gauge stayed at half way, just like it does going down interstate at 60, any faster than 60, and the temp. climbs.

I had what seems like good flow in the rad., but something is amiss. I am gonna replace the temp sensor tomorrow. I just wonder if the block may need flushing.

 

Replaced the temp sensor and the fan clutch today. The fan clutch was toast compared to the new one. I can feel it pulling air thru the grill now.. I let it run for 20 minutes witht eh a/c on, and the temp stayed a little above a 1/4 on the temp gauge. now for the highway test tomorrow.

 

I'm gonna guess that it still over-heats.....doing that on the highway sounds like a semi-clogged radiator. Never heard of a brand new one being clogged though.
Is there mud in the radiator fins?

 

No ZUK, the rad.and the ac are both very clean. If it over heats tomorrow I am replacing both lower rad. hoses.