So ive had overheating issues in the past but this one is new. Ive replaced the radiator, water pump, thermostat, passenger side coolant temp gauge sender, driver side coolant temp switch (all like 3 years back) and now ive replaced the cooling fan relay. The problem is that the coolant temp will reach 211 and where the radiator fan would usually turn on and run until the temp goes back down, it does not do that anymore... instead the fan will just turn on for like a minute and then shut back off, and then it'll turn back on and shut back off again minutes later. this leads to the coolant reaching overheating issues. so... any ideas???? im really struggling with this one

 

Your fan should not come on until it reaches 230 degrees. Have you changed anything that it was turning on at 211 degrees?

 

I am not the original owner (cars twice as old as me) much to my dismay. The guy who owners it before me also put a bunch of bullshit modifications so I can’t tell what’s stock and what isn’t due to a lack of knowledge on my part. I just assumed that’s when the fan turned on. At least mine turned on always around 219 ish

 

What temps are you seeing during normal driving? If the highest you are seeing is 219 or lower all should be good.

 

Find something that you can plug into and read the temp the ECU is seeing and when it's calling for fan-on.
The gauge sender is a separate deal.

 

Hi you can always try the following to check your cooling fans and get them running manually, unplugging the small round plug on the a/c line at the passenger side low near the frame rail. The one next to the slightly larger high pressure cutout switch with two spade terminals, removing the small round plug will activate the a/c fan or main fan depending on if you have a booster fan in front of a/c condenser.

Otherwise the single wire connection plug on passenger side head, remove that and ground it to turn the cooling fan on.

The early c4 had two temp senders, one for dash gauge the other the ecm. The ecm has its own temp sender to activate the cooling fan, from ecm cooling fan set point or the temp sensor on passenger side engine head between near spark plugs 6 and 8. The ecm also activates the fan when receiving the a/c cooling fan request from that small round pressure switch, the diagnostic port under dash can be used to check fan relay. Connect a paperclip between A and B (the top right terminals) that will activate the cooling fans when turning ignition switch on but not starting car, while in diagnostic mode to check engine codes.

Corvette central sells a lower temp switch for the passenger side cylinder head, for those that want to turn the cooling fans on at a lower temperature compared to factory 238 cooling fan set point. However most people use a simple dial adjustable thermostat temp controller with capillary copper sensor bulb you fit in the top radiator / hose, that can be set to whatever temp you like. Just connect to the adjustable thermostat switch wiring to the temp switch on passenger side head and other side of adjustable thermostat switch to ground.

https://tech.corvettecentral.com/201...modifications/

https://www.ebay.com/itm/332822885693

 

There are some pretty good aftermarket fan controllers these days.
https://www.corvetteforum.com/forums...eaningful.html

 

My '94 LT1 base auto always runs a steady 184'-185' on the highway, ambient temps below 90', 187-190' for temps > 90'. Town driving, <90' ambient, 201, >90' town, coolant temps 205', never been above 209', that was an ambient of 201' in town. "Upgrades," PCM4LESS flash that turns fans on at 197' and 205', 180' thermostat, Dewitts Direct Fit single row radiator, coolant flush, and clean AC condensor. Auto fluid temps are another thing... Too high, new transmission, so i'll be addressing that very soon with a stacked plate cooler.

My '96 LT4 runs highway at 183' and lower with ambients below 90', depending on ambient. 195' in town, no higher. Haven't driven it yet in temps >90' on highway or in town, so i don't kow those temps... Yet.. The car is all factory original. Clean radiator/AC condensor, coolant flush, and PCM4LESS flash.