Have a '04 blazer with 100k that was overheating during a 600 mile trip in Florida 84 degrees outside. I had the manifold gaskets done at 80k. I also did water pump,thermostat , fan clutch and drain and flush at that time. I'm towing a pop up at 1800gvw with 1 person, two dogs and gear , MAYBE 2500lbs total. I hit prob 230-240F about an hour later. Much to my dismay I stopped at an AAmco and redid the flush and thermostat and had em put a tranny cooler. Still ran 220F. Can a blazer really not handle that weight? Thought they were pretty descent tow vehicles. Who's towing here and how's yours handle?

 

this should explain your last question

https://blazerforum.com/forum/genera...k-46275/page8/

 

What gear were you towing in?

 

I've used mine to tow a 6x10 enclosed trailer packed to the gills with sound equipment numerous times, which if you've ever moved speakers and amps you know this stuff ain't light. I never towed it very far but I have hit highway speeds with a loaded trailer (towing in Drive, not O/D) and it pulled just fine with no overheating. I would have to agree with pettyfog, were you towing in O/D? Because that will do some serious damage...

 

What'y'a mean 'agree'? I didnt say anything....


..... yet!
But now I will.
Here's a tip from the ol' timer kiddies; anytime you approach your vehicle's GVWR, whether it's with a trailer full of camping gear or just the truck loaded with a couple million in gold bullion, and if you're not in perfectly flat country, you've passed the point where you should use Overdrive. You dont even have to calculate wind drag from the trailer. If you're serious about it, then do that as well.

But you have to understand what Overdrive is meant for: a nominally loaded car or truck at cruise speeds and power.
Then you have to understand that is 'economy mode'.

The power curve is well above the cruising RPM range. If you're towing any significant weight at all, then you need to go to 'power mode'.

And that means keeping the engine rpm at 2500 or above. Doing that circulates coolant faster, pulls more air through the radiator and makes the engine more efficient at the power it's having to provide.
This isnt the same 4.3L tech as vin W, exactly but it's close:



Serious weight towing, read this:
GCWR

 

I towed my parents 20' Four Winns boat last summer on 60 mile round trips to the lake. Had no problems whatsoever with overheating. I tow in 3rd gear unless I am towing something light enough to keep the trans from shifting in and out of OD. I was also towing with steel wheels wrapped in 31" tires with the A/C on in 90 degree weather.

Sounds like something is definately a miss with your Blazer.

 

Well, I was towing in drive, only cause in 3 the rpms were higher and I thought that would cause overheating. I'll use 3rd gear goin back if at 65mph it is better or even recommend. Thanks for the info!

 

So I drove back in 3 with no change. Had to ride with heat on and multiple stops. Noticed just driving around town today With no trailor it was running 210?! WTH is goin on? No leaks anywhere. Really scratching my head on this one. Any thoughts?

 

Maybe your fan clutch is shot. Just a thought.

 

If it's the fan clutch it will run normal temp at 60 mph empty