Well, it means it not shot, but not necessarily that its in perfect working order (like I said before, you need a strobe scope to check it while hot). The cooling system is overbuilt on these trucks so it can probably handle cooling an unloaded truck with an iffy radiator but not with a heavy load. Have you tried pulling the radiator and back-flushing it? The same SCA that protects our engines from cavitation can flake off and clog the radiator so back-flushing might help. Probably wouldn't hurt to wash out the fins too. Best case, it fixes it, worst case, it doesn't and you replace it.

Now that I think of it, if the radiator is clogged, its not throwing off as much heat onto the fan clutch, so it probably won't kick in.....

 

Last time I heard of someone having a overheating issue it was the reservoir cap.

 

If you have access to a laser temp probe, try bringing the truck up to temp, then take heat readings at different points on the radiator. This would give you some idea if there are clogged areas in the radiator.

I'm still leaning toward your clutch... I replaced mine even though it "passed" the cold resistance test. Most people pay no attention, but when your truck has sat over night, and you get in to drive for the first drive of the day, you should hear a pretty loud "blower" sound for the first couple miles. This is you fan as the fluid in the clutch is spun to the outside of the housing. (it settles over night) Mine stopped doing that, but still had resistance when cold. Prior to replacement, my fan would kick in, and I could hear it, but nothing like the engagement after I replaced it. So yours may be engaging, but slipping too. I went with a NAPA HD replacement, and when it comes on now, with out fail, if I have someone in the truck who hasn't heard it, they always ask "what is that"... even if the radio is on .

Just a side note, I don't tow much, and have removed the fan altogether for winter month operation for quite a few years, temp gauge didn't budge... this gives my water pump a vacation from that 20lb punisher, prolonging it's life.

 

FWIW, Duckfan (Pete) was driving home from RRE last year and was having overheating problems and it ended up being his radiator. His was overheating without a load.

 

I also remember reading that. These radiators do get plugged. More and more guys are useing coolant filters to keep them clean as possible. I still vote for a radiator but please keep us posted on the fix. Chet

 

hey yall sorry it took so long to reply but i finally got the work done. I replaced the t stat and still did not fix the over heating problem. so went ahead and pulled the water pump and the radiator. the radiator appeared to be clean and un damaged. the water pump had a pretty "loose" bearing. not shot yet but certainly not in great condition. Went to the rad shop and was going to have it rodded and was going to take 3 days to get it back so i just bit the bullet and bought a new water pump and rad. Through them in and shes running nice and cold. So i wish i could have pin pointed what it was but becuase the water pump was still circulating water im going to assume a clogged rad. thanks for the help. logan

 

also to any one else having similiar problems dont be to affraid of doing the work, it was incredibly simple and lots of room to work. water pump at o reily was 250 and new water pump was 150. not to bad and it fixed the problem!!!

 

sorry rad was 250 water pump was 150

 

Thanks for following up and letting us know what fixed the problem.

 

Hick51 glad you got it. Chet

 

That's not a bad price, I haven't shopped around but I know it's a big radiator.

 

Does your new radiator have a built in OTW (oil to water) transmission cooler?

My 2000 didn't come with one, so if yours didn't and the new radiator has one you could benefit from hooking it up.

 

Logan - you can always cut/break off the top of the old radiator (if you have it) to see if it's clogged. If you're going to junk or recycle the radiator, it won't be worth any less with a broken plastic tank. Doing this helps you learn what the problem really was.

 

I'm still looking for my "throttle body" so I can space it out.

Or maybe I'm just getting "spaced out"......

Pop

 

For $83, my throttle body can stay where ever it's at.