My 1980 Silverado build thread

[SLDPULR]

Originally Posted by z71se

Let me just start by saying I have built a couple LS iron block, turbocharged trucks and none of them had any cooling issues whatsoever. My 2005 had a factory 1-core 1" thick aluminum radiator (with 165k miles) and OEM electric fans and a factory 197* tstat and a factory 165k mile water pump and had absolutely zero cooling issues. If you make a post on performancetrucks.net you'll find very little mention whatsoever of overheating issues. In fact, overheating on any LS motor, iron block or aluminum, is uncommon unless there is something functionally wrong with the cooling system.

One issue I have had in the past is an issue with aftermarket water pumps vs OEM water pumps and the thermostat not seating properly in the water pump housing, which led to the thermostat not opening at all. If I had to guess, that would be your problem. If you're not losing coolant which it doesn't sound like you are. When I had my thermostat issues, the hoses would get real hot but I couldn't get any circulation through the system. By adding a 160 tstat, you're bandaiding the problem, but it might resolve your thermostat opening problems. If I had to guess, you're running a parts store aftermarket water pump?

That is true it is an aftermarket WP.

The motor is out of a 2006 Yukon Denali. When I got the motor it had a very new looking water pump. I just thought I got lucky that it had already been replaced. It would have never crossed my mind.

Would a good AC delco unit be the best replacement?