While towing my searay, all in all its around 3200-3500 pounds depending on gear and fuel, i have to go up a 10 mile long 7% grade, going from 4800 to 7200, feet in elevation, speed limit is 50mph, and i keep it in second around 45-50mph at 3.5k-4k rpm, it starts to heat quickly, i keep the heat on full blast with windows down, its around 80-100 deg out side.

Its got a new radiator, new heater core, no water leaks, anything above 210 the fan clutch kicks on, and it sounds like a jet plane, so i know thats working. Im thinking about getting an aux trans cooler and get that out of the radiator completely, to make less heat there. Ive never let it get above 220, so i pull over alot. Dont think its got head gasket issues.

Any ideas?

 

quick question, when your pulling it do you have the a/c on? if so try turning it off once for like 5 mins and see if the temp goes down. My blazer gets hot when the temp is over 90 and the a/c is running while pulling a load, but i turn the a/c off and she drops right down.

 

Nope i have the heat on full blast as soon as i start going up the hill, to try and rid as much engine heat as possible, if i had the ac on it gets hotter a lot faster.

 

What happens if you leave it in 3rd rather than 2nd?

 

Its a windy mountain road so if i leave it in third, it has to down shift to second all the time to get up to speed, then up shifts when i go into a corner, then back down out of a corner, so i figured that would fry my trans. Still heats, i figured second would spin, the water pump more. Still looking for a larger radiator for it. Stock seems small.

 

I don't think there's much you can do since you're pushing the limits of the cooling system by maxing the towing capacity. I'm not sure how it's calculated but I assume the max is not based on pulling a trailer up a hill in 100 degree heat. Do you have oil and tranny coolers?

 

I haven't looked to see what the Blazer will tow but I can tell you I wouldn't tow that much with mine and then add a steep grade on top of it. It is overheating because you are pushing it to its limits. You can see if anyone makes a two row rad for the Blazer but other than that you should consider buying a truck.

 

One thing that will give you a couple of degrees is a real good cooling system flush and a "go easy" power wash of the radiator.

 

Would electric fans help? Thats about the only thing i can think of.

Even when my dad pulls our 21' Searay with his new suburban over a pass in about 100 degree weather it will overheat and the tranny will get to about 260. We just make a couple stops to let it cool.

 

The tow capacity is 5k, funny thing is, is that it has all the power i need. i could go 70 up the hill if i wanted to, so i will try and modify to get a larger radiator in it. I dont think electric fans would help at 50mph, fans are use less, as more air is being forced in.