Smokin 100HP Club
Join Date: Jul 2012
Location: Pittsburgh, Pennsylvania
December 2012 there was a thread discussing this issue. See C4 Tech & Performance. Thread title "Antifreeze". On 90 degee days I was seeing persistent water temperatures at 240 plus degrees. So even though the electric fan was kicking on at 228 degees; temperatures remained at 240 degees. This was quite unnerving. A kind gentleman from California (Toobroketoretire) had personally contacted me and educated me on this topic. Everything stated in this post and the Decembers post are true. To summarize, you can narrow down to three major factors. 1) Antifreeze: as antifreeze ages the boiling temperature threshhold drops. New 50/50 antifreeze boils at 260 deg. Then boiling temps start dropping affecting coolant effeciencies. Coolant flush recommended every two years. 2) Radiator: for some reason GM used single tube radiators. Why? Doesn't make sense. This really limits your heat sink. Plus as the core ages; it corrodes and restricts flow. As most of our radiators are approximately 20 years old, you can be sure you have corrosion. 3) Electric fan: For my 94 the fan kicks on at 228 degrees. There are ways to drop this thermostatic threshhold.
What I ended up doing was replacing radiator with a two row direct fit aluminum made by DeWitt and flushing the coolant. DeWitt makes a fine product at about 60% the cost of a BeCool. And Frankly, I think they are designed a bit better. I finished this project 8 pm this past new years eve. So I won't see any 90 degree days in Western Pennsylvania this time of year. I am expecting to see some improvement by doubling the heat sink capacity (I would be happy with mid to high 220's). But I'm also planning on coverting the electric fan switch to a lower temperature if needed. I also remember reading, where someone replaced their single tube radiator with a new single tube and seen temperature improvements. I suspect corrosion was a factor. One last thing...go green on your antifreeze. If you have red antifreeze...get that junk out of your engine.
Last edited by MarkyMark; 01-24-2013 at 05:42 PM.