UH-OH!! Did I make a Mistake ? Overheating now!!

[86er]

IDAHO: Also consider changing the temp sending unit to turn on the fans at a lower temp. Look in the Eckler's or Mid America catalogs for this part. Mine turns the fans on at 200 degrees and am very happy with it.
VINNY

For $25 or so, the automatic fan switch is a great solution. On @ 200 and Off @ 185.

BTW: To further BURP the system, let temps get to normal range, rev rpms @ 2000 for 30 seconds and cap radiator while still @ 2000.

 

[Rain]

And to answer one of your other questions, no, you dont really need anything else to do the TB Bypass.
(except the rubber caps to go over each end of the TB.)
Rain

 

[WhalePirot]

Ummmm, I believe that the ECM took over the fan ops in mid '85. No separate sending unit, then; no replacement, with lower trigger temp. I believe that the ECM gets reprogrammed to turn the fans on sooner in those cars.

 

[Jersey-vinny]

Whalepirot: I don't understand how the ECM and the fan switch can both do the job but the switch works fine in my '88. The Eckler's catalog has the 200 degree switch ( part # 40290 - $ 39.99 ) listed for 1984-1995. They have other switches which activated the fans at even lower temps.
VINNY

 

[NewGuy]

My Corvette shop told me not to put in a lower temp thermostat. Instead he reprogramed the computer to turn the fans on earlier.

There may be an issue with a thermostat that is too low. Remembering this from old days before electric fans and computer controlled engines.

A thermostat does two things: Allows coolant to flow at a certain temp from the engine and it forces coolant to stay in the radiator longer if that temp is not reached. So, it may be possible that the coolant is flowing too fast through the system, not allowing enough time to cool. This may not be applicable to modern cars but just a thought.

A friend an I both had LT4's. He put in a lower thermostat. Both of us had the cpu's reprogramed for fans to come on earlier. His runs in the identical temp range as I do. Normal 190-210 or so, very hot days, bad traffic, 225. Immediately cools down once traffic starts moving.