Electric will certainly move more CFM especially at idle. More air seems to be the only thing that proved any result. I would go that direction if all else seems to have failed.

 

Replace the fan clutch?

 

Check the fan clutch relay if it has one. I used to have a 2005 Trailblazer that started overheating at idle sitting parked or at stoplights. As soon as I started moving the temp went down. I made it home and took a look under the hood. Everything seemed to be working, even the fan. I took it to a shop and expected the worst readying myself to pay for a new thermostat and/or fan clutch plus labor. The shop called after a couple hours to let me know the truck was done and the total bill was $22.00. WHAT?!?! The guy laughed and said it was only a bad relay.

 

It's a mechanical clutch, there shouldn't be a relay for it

 

It's a mechanical clutch, there shouldn't be a relay for it

Ah ok. I wasn't sure about the Silverados but thought I'd throw that out there just in case..

 

i got a 2000 suburban for $400 it had the same problem i took the rad cap off the tank and the oring was missing, new cap and it was fine after that, check it for cracks or missing oring or it could be just bad and not keeping pressure.

 

now is it really over heating or dose the dash say it is, get a temp gun shoot at the rad then at the hoses if the same temp I would say its a gauge issue or sensor telling the truck its hot, not if the rad is cooler then the hoses its usually bad thermostat or to "high" of one, not opening at the right temp

 

My vote is replace the thermostat and coolant temp sensor while you're at it (cheap and easy) Then the fan clutch.

 

Fan shroud still in place?

 

Fan shroud still in place?

you would know if it wasent wack wack wack lol

 

any update?