Z71chevydefender

Hey guise I have a problem with my 08 silverado... just as the title says, the engine overheats on the dash gauge up to 230 degrees but will drop back to normal if i coast down a long hill while towing. If im just cruising thats a whole other story it stays right at 210 degrees. Today I was towing about 9k pounds in an enclosed trailer for about 75 miles and boy did it have a hard time keeping cool. the truck gauge read 230 most of the time, my superchips vivid said the engine maxed at 240 degrees and the transmission stayed at 220-230 most of the trip. what i found was that when coasting my engine would return to normal temp. while the tranny would stay in the 220-230 range, this leads me to think the fault is caused by the tranny overheating the oil thus overheating the engine through the coolant in the radiator??
if it helps to give insight my truck is a 2008 silverado 1500 with the 5.3...

thunder550

iTrader: (70)

Mechanical or electric fan? I don't think the tranny cooler has enough influence to cause your problems. Is your truck stock? How many miles?

Z71chevydefender

it has electric fans, it is for the most part bone stock. I even returned my truck back to the stock tune for the tow. I may be wrong but the truck's radiator has a trans. cooler built in and then it goes to a secondary factory oil cooler in front of the radiator. that is why i thought it could tie into my engine overheating.

Suburbazine

Electric fans knock about 900lbs off the max towing capacity. And 9K is waaaaaay outside (more than 1000lbs) the rated towing capacity for that truck. So now you're roughly 2000lbs over the limit and in addition you're pulling something with the aerodynamic properties of a parachute at 75mph. Am I close?

For reference:
http://media.channelblade.com/EProWe...08TowGuide.pdf

For that kind of load at that kind of speed, I'd say you're looking at a 2500HD or even a 3500. You might have a Class 5 Hitch (12,000lbs) but that's by no means a Class 5 truck you've got.

Z71chevydefender

yeah :/ i know I was way over my tow limit but a few months ago it also happened while towing a trailer with four bales of hay. it was only about 3000-3500 pounds trailer and all... I am wondering if I need to increase my cooling capacity. would a 6.0 truck radiator be a direct bolt on for my truck? would I benefit from extra capacity in the cooling system? I need help guys, but I like to keep my mechanical parts as close to stock reliability as I can. let me know what yall think.

BigKID

iTrader: (5)

If you have factory efans, you already have the larger radiator. With the weight of a crew cab, the heavy front bumper/brush guard on front and the wheel/tire combo (look to be at least 33" tall), assuming you have 3.73 gears, I think you truck is just plain overworked. If you tow that much weight often, your best bet is a set of gears to help with mechanical advantage. As for immediate cooling relief, look into you coolant mixture. A 25/75 coolant/water mix with a bottle of water wetter or purple ice could help transfer out more of the heat your building while towing up hill.

thunder550

iTrader: (70)

You could try installing a mechanical fan as well.