Strange Cooling Issue on 5.7 engine!

[Corts60]

Originally Posted by ballencd

Corts60....Apparently your reply went to my Junk Mail box and I just caught it.

Thanks for the response. I will rent a tester and try the tests. Sounds simple.

As to the radiator, it was ordered as a replacement for the OEM radiator and looks about the same size.....maybe a bit thinner but its been awhile now so I will have to compare it to my 88 Burb. It still has the OEM radiator. Not sure when the problem started. The car had been sitting for about 9 years when I bought it and I put in the rad almost as soon as I got it because of leaks. Maybe....maybe not changed. It runs on the highway fine between .... maybe 160 - 180 degrees and around town if I don't go too slow or dawdle.

The fact that the upper hose seems empty until the thermostat opens bothers me. Seems like it should not have that much air in the system...???

I'll let you know what I find but it may take me a few days to test it.

Thanks again.

Sounds good. Be sure to text that cap too. It has a vacuum release as well as a pressure release. If the vacuum release doesn’t work when the engine cools down, it often sucks the hoses in