Allan Weiss

I recently purchased a '96 LT-4 coupe with 119,000 miles. She runs very strong but the temp goes up to the 3rd mark on the gauge before the fan comes on. I found sending units that reduce the temp the fans come on but they are only listed to the '95 for some reason.
Is anyone else concerned about running that hot before the fans come on?
How about a fix?
Thanks,

Al

Silver96ce

The fan temperature turn-on and off points are controlled by the ECM (the engine computer). On prior years you could install a switch or lower temperature control sensor but not on the '96. You can either have an engine tuner reprogram the temps or you can get a Hypertech programmer part no. 30027 to program it yourself. If you go the Hypertech route look for used that has been "restored" to factory otherwise it is expensive.

Just so you know these cars are designed to run hot for emissions and performance - lowering the temps too much can be just as bad. If you haven't already done it - flush the cooling system; put in new coolant; and remove and clean the radiator fins, the area where the radiator sits and the a/c condenser. That will help it run correctly.

Kmcoldcars

Your car is designed to run at temps of about 200 to 210. The fans do not come on until about 229. To see what the actual temp is use the digital gauge. You can see it by pushing the gauges button on the dash until the water temp appears. It should be accurate. The analog gauge is not linear and does not show the actual temp. It is there to let you know if anything changes from the normal operating temps.
The car should run around 200 - 210 while going down the road. When stopped the temps will rise rather quickly as there is no airflow through the radiator. If the temps come down when the fans come on then everything is probably OK.
If the car gets hotter than about 210 while going down the road then you probably need to clean out between the radiator and the A/C condenser, as this area will gather lots of junk from the road.

bob guzzy

Put a simple switch inside of the glove box, run a wire from 1 or 2 of your fan relays, switched on you ground the relays.

Switched on the fans will run at your command, left in the off position the fans go back to the way the computer runs them.

I have added this switch to all of the corvettes I have owned, it gives you some peace of mind wile sitting at a light watching the temps rise, simply turn on the fans for city driving shut them down for your interstate runs.

RollaMo-LT4

One of the worst things Chevy did was put an analog temp gauge on these late model C4's.

Next to impossible to tell exactly what temp that analog gauge is really displaying, unless the needle is pointing exactly on a number.

"Hot" for the analog gauge would be having the needle actually moving into the "shaded" area on the gauge.
Just before it reaches the shaded area, the digital will be reading approx. 230°F
And for a modern cooling system (with proper coolant mix and pressure) is not that hot.

Allan Weiss

Thank you. I already bought the toggle switch but I could not find any place in the firewall to feed the wires. Any suggestions ?

Silver96ce

IIRC if you wire in a manual switch it will cause DTCs (trouble codes) to set. That is why all of the manual switch and other fixes only go up to 1995 (OBDI). 1996 is OBDII. I don't think a manual switch will affect how the car runs however - but don't rely on my opinion for your peace of mind.

Allan Weiss

Thanks to all for your advise. I will go to the digital gauge and go from there.
I feel better knowing it was designed to run hotter then I'm used to.

tahoemedic

These cars run hot normally. The analog gauge is the temp reading right at the head. It should almost always be cooler than the temp reading on the digital gauge (at the waterpump since that is the water returning to the radiator). Do the basics like what was already said; clean out the space above the air dam where the radiator gets the air, flush the radiator, and if necessary, have it pressure tested or rotted out. These cars have plastic resevoirs and small cores in the radiator so they aren't as efficient as they could be.

Voxego

Shoulda bought one with the Atari dashboard, Big Al!

tbirdsps

Check out that radiator face. Mine was a disaster, once clean the temps are quite normal and only approach 220 in stop and go traffic.

mrmtrtrnd

[QUOTE=tbirdsps;1583660766]Check out that radiator face. Mine was a disaster, once clean the temps are quite normal and only approach 220 in stop and go traffic.



That is the first thing to check when the car is running hot. These C4s are notorious for vacuuming up everything off the street.

Allan Weiss

[QUOTE=mrmtrtrnd;1583660881]That was the first thing I checked. Mine was clear. I understand that a small screen can be installed under the nose which would be easier to clean.

96GS#007

You need a 3 position "On/On/On" switch for the '96. It will allow you to run the fans at low speed and hi speed. Here's the schematic so that you won't toss any codes...

TommyFox

Yeah and then ditch it for some gauges that actually work.

Voxego

Hey, I've only had to get mine rebuilt once!

TommyFox

Give it time.

ColaBear

96GS#007,

Does your change to the circuit allow for the standard fan control when not in low or high speed since it uses a 3 poll switch?

96GS#007

Yes. One position is standard "factory" control. One position runs both fans on low speed. The last position runs both fans on hi speed. It will not set the SES light either.

ColaBear

Thanks for the feedback. I am going to look at building this harness mod. Where did you mount your switch?