LT4 Keeping LT-4 cool in traffic?

[LT4_UK]

Yesterday when I was in heavy traffic my temp guage crept towards the shaded area and the digital readout read 230 before I heard the fan (s) come on and the temperature started going down.

As far as I remember from previous C4 Corvettes I have owned this is pretty normal and the temp went down as soon as I started moving over about 5 mph, when the spoiler can direct some air over the radiator.

I have address this with my previous C4s by buying a manual override fan switch but they only seem to be available for up to 95 models. Is there one available for 96 cars and will a lower temperature thermostat help? I have read they can mess up your mixture by lowering operating temperatures and I don't want to start getting other issues.

Or if a fan kit isn't available is it possible just to make one up?

Both fans appear to be operating correctly on my car. It does cool down (a bit) when the fans come on in traffic but I'd rather not wait until it gets to 230 degrees first!

Malc

 

[93Rubie]

It will not hurt the car any to run cooler. I would not mess with the thermostat. Its a 180 or it should be. You can run a manual fan switch but it will turn on a check engine light. Being a 96 and OBDII it should be very easy for someone with a tuner to get the fans to turn on sooner. You would have to check on this but one of those plug in handheld basic tuners may even be able to do that. Hope this helps some.

 

[Tuna]

This is normal for an LT4 and should be of no concern.
Both the LT1 and the LT4 are programmed that way.
The first time I saw that with my old LT4, it caused me some concern but it is normal.
You can spend money on switches and computer re-calibrations to make the fans turn on sooner but it may be a waste of money.

 

[Hib Halverson]

My experience with the late C4 cooling system is that, if the rest of the cooling system is in good condition and the coolant mix has been altered to increase water and reduce antifreeze then having the calibration changed--either with a handheld programmer (1996, all and 1994-95 LT1) or with an aftermarket calibration 1990-1993--to lower the fan-on temperatures is a useful modification. I have that done to my 95 Cpe and the result was lower peak coolant temp and more consistently lower engine coolant temp.

I do not recommend "manual switches" because few drivers are attentive enough to engine coolant temperature to control the ECT properly. You usually end up with much larger swings in coolant temp than you would have without the manual switch.

 

[LT4_UK]

Thanks for your replies

From memory my previous C4s also ran like this, it's just a bit scary seeing the temperture go so high!

The "temperature curve" would seem to be quite flat in as much as my car runs in the 180s or 190 degrees even on the highway.

I have been wondering though why the manual fan kits are available for up to 95 but not 96?

I think I will invest in a handheld programmer at some point. Any recommendations and what else can be done with it?

I am also wondering what computer program to invest in for diagnosing how the car is doing..

Malc

 

[93Rubie]

You can get software to run on laptops that will allow you to see just about every sensor read out on your car. However, if you are primarily concerned about it running correctly, being a 96 with OBDII which monitors WAY more than the older OBD1 95-84 C4 cars, I would not worry about it unless the check engine light is on.

Keep in mind most modern cars with normal cooling systems run 195 thermostats so they run down the road actually hotter than a well maintained LT1/LT4 car. Mine usually runs around 195 on the road...which is the MIN. operating temp for my 2001 Ford Focus Daily Driver, so it is hotter running down the road than the Vette.

 

[Kevin Doyle]

Hyper tech tuner

Thats the only reason I bought a hyper tech tuner so I could program fans myself on at 210 off at 200,Kevin.

 

[trourke162]

If I'm in traffic and the temp starts to climb on my LT4 I turn the air on and the secondary fan comes on and the temp drops.

 

[LT4_UK]

Cheers dude!

If I'm in traffic and the temp starts to climb on my LT4 I turn the air on and the secondary fan comes on and the temp drops.

I just tried that and it probably is the best option.

I could swear my fan would keep running after shutdown on one of my other C4s if the engine was hot though I can't remember which car.

I have added the manual fan switch on my previous C4s but hitting the air control may be as good as any solution...