I've got a supercharged l92 in my truck. Also have a double thick aluminum Cold Case radiator. While towing I've had some overheating problems when its really hot out. Temps will climb up and past 230 almost to 260 sometimes when cruising around 2-2.5krpm or when stopped at a stoplight. However if I'm moving and downshift around 3-4krpm temps come down pretty quick.

I know my efans and radiator are not the problem because the difference in inlet and outlet radiator temps are good. Is my water pump just going bad or do I need to look into upgrading? If so what water pump upgrades are available? Is there an option with a smaller pully to spin it faster.

 

Definitely something going on here…it should not be running that warm at that rpm. What truck is this in? Do you have a big bumper/brush guard/winch up there impeding airflow? What coolant are you running? Factory t-stat? And lastly…did you post this today during MATLAB? 😜
Welcome to LS1Tech!

 

Casey Wegner makes the best WP for LS engines.

 

Hummer H2. Yes winch, brush guard, a restrictive front grille and factory t-stat and dexcool. However it does have factory efans and pulls plenty of air through the radiator. I can touch the cold side with my hand, I cannot touch the hot side without burning myself, and as the rpms increase, temp goes down.

And yes I did post this today during MATLAB. ****'s so boring.

 

$700 for a water pump is crazy work.

 

Does this radiator in your H2 have the transmission cooling circuit? If your trans temps are soaring while towing, it will affect your water temps significantly. Do you have a trans temp gauge in the display? My son Brandon sits beside you in MATLAB. He mentioned to me you were posting, so I had to bust your ***** there. LOLLLZZZ. Boring indeed!

 

I bypassed the trans cooler and ran an very large external one. The other day, after a drive though, I opened the hood and noticed the hoses had no pressure. Coolant was still full. I replaced the reservoir cap. Went from a 15psi to a 20. I wonder if if was failing and losing pressure causing the coolant to cavitate when water flow is low. Seems to be holding pressure now, but will have to wait for some warmer weather and an excuse to tow something to see if that fixed it.

I'm sure Brandon has told you all about that class. Professor has a 1/5 rating on ratemyproffessor. Literal walking potato.