I thought it might be helpful to follow up on a few loose ends in this thread (which I also discussed in my
build thread):
The PO confirmed that this beast does in fact have a new radiator, along with new upper and lower radiator hoses, plus a new radiator cap. So far so good.
My plan is to do a drain and flush, and replace the thermostat with the newly purchased GM one. I'll probably use a 50/50 premixed antifreeze.
Upon inspecting the cooling stack (I learned a new term!), I found the fins to be clean, unbent, and one can easily see through them. Nonetheless, I'll blow some compressed air through them, with reduced pressure to ensure fin safety.
It turns out that my auxiliary fan does work. After a long drive I visually checked it while it was parked and idling, and the ECT was just below 200º F. The fan shut off when I turned off the ignition.
Still haven't decided on a fan, but I'd want a simple bolt-on solution. I'm not 100% clear on what part #s I would need to make that happen.
Lastly, even though this thread was about engine coolant temperature, the topic of transmission fluid temperature did come up and was discussed enough to warrant passing along what I learned from Trent, the guy that rebuilt the transmission, plus the GM SM. Trent said that the TFT really shouldn't go much above 230º F. The GM SM, Book 2, Page 7A-370 states that the normal operating range for the 4L80e is 90º C to 115º C, or 194º F to 239º F, depending on load.
Our next trip is in early July, again to the mountains; and I will report back how it went, temperature-wise.
