Why Do Our C4's Run Soooooo Hot??

[AWSUM93]

I love my 94 polo green/saddle vert' But after having 3- C4's I really chevy didn't solve the problem of soooo much HEAT!!!!!
What do you guy's do to "solve" this problem?

 

[rrhayden]

Hi,
I have a 92 that was also running HOT. After reading posts here I found that it is normal for the radiator to pick up all kinds of trash and block airflow. If you look between the radiator and ac condenser, I found it filled with over an inch of crap. I removed the radiator, per the posts here and cleaned it. I now run 20 degrees cooler. In 80 Degree heat, I run between 190 and 196, at a stop it sometimes climbes to 210.

 

[sothpaw]

Those numbers are normal.

But if you think they are high, and I do, then I have one word for you to really explain why C4's run hot:

Emmissions.

 

[Rogue]

I noticed my 1991 L98 gets above 200 in stop and go traffic. But as soon as it starts to move even at a slow 40 mph the engine temps goes down right away. So, I just try to avoid stop and go as much as I can. It's not my commuter anyway so this is not as much of a problem for me as it is for some.

I also noticed a bit of heat coming from the floor next to the transmission tunnel. Not much I can do about that except turn on the climate control. It seems the only way to get fresh air in my cabin without turning on the Climate Control is to open the windows. The window is a long ways from the floor so that doesn't help!

 

[trrgod]

It's very true that a lot of crap clogs the radiator on these cars. I've cleaned my several times. It WILL make a difference. Also, you can buy a switch for your car that turns on the fan sooner. Check the Vette catalogues for this set up on your year car. It's called and aux. fan kit for my 89. I put one on and the front fan now comes on at 204 and helps to cool the car is stop and go traffic.

 

[blackvette89]

i just got my kit in to lower the temp/activate fan earlier. my 89 has only one fan. how difficult is the add on?

 

[Radar]

Blackvette89,

My 89 has the single fan too. The engine computer chip controls the cut-in and cut-out temps for that fan. You can by a chip like the Hypertech Stage II that drops the fan cut-in to 174 deg F. Works great for me. I run a 160 deg engine thermostat and my engine runs nice and cool. I was out yesterday in 89 degree weather and I was about 187 degrees water and 201 degrees oil.

There also is a member on this site, I thinks it is Jeff, who can custom program a chip for you. If you do a search for "chips", you should find his posts.

I would do the chip route before adding auxillary controls onto the fans with the single fan setup.

Hope this helps,
Radar

 

[vader86]

They are designed to run hot because of emissions.

Clean off the front of your radiator, behind the condensor.
Wire in a fan switch and your troubles should disappear.

 

[trrgod]

There are a couple of ways to get a front fan for 84-89's. One way is to buy one on ebay but then you'll need to find a way to wire it in. Another way is to buy a kit for a front fan out of one of the catalogues. Or a combination of the these. I've seen NEW auxilary fans on ebay for $40. Maybe then you only have to by the wiring kit. Just for those who aren't sure, on the 84-89's the aux. fan is in front of the radiator (easily seen by looking into the mouth opening from the front). Later cars have two fans behind the radiator. You can drop the temps on the later cars by the methods such as Radar has or a kit offered in the catalogues.

 

[Corvette-Pilot]

Those numbers are normal.

But if you think they are high, and I do, then I have one word for you to really explain why C4's run hot:

Emmissions.

;stupid
Dam Feds

 

[Mika]

Maybe you have solved your problem, but I have share this information and some tips people gave me.

1. Change coolant if old.
2. Change Thermostat (I used the orginal)
3. And like others said clean the radiator


I did all those things and still my C4 had cooling problems. Many said also that I should change my chip`. I monitored the problem and noticed that my fan1 didn`t always start when it should. -90 model has two fans and second starts very late when there is already too much heat so the fan1 is very important. I took it in service and they said that they tested it and everything was ok. Two different places said the same thing that no problems.

I still didn`t believed what they said because sometimes engine was running VERY hot. Then I took it back to local service shop and then they found small problem.

The Fan relay was broken and worked only occasionally. So When the relays were changed then temperature was dropped at the normal level.

4. Change Fan relays


All these 4 steps are very easy/cheap to do.

 

[warren s]

Put in a 160 degree therm.
Change the coolant
Bypass the TBI collant line
HARD WIRE the 2 fan relays to come on when you want them to.

 

[warren s]

Check out my thread "Fan switch overide for 3 bucks"

http://corvetteactioncenter.com/forums/showthread.php?s=&threadid=27982

I posted some pictures on how to do it.

 

[larry bud]

A 160 therm is not going to do anything different in the summer as opposed to a 180 or 190. The temp is already above those thermostats, and they are already open. The only thing different is the therm will open a bit sooner.

If you live in cold weather, it will make a difference in the winter, but that's when you want it hot. I think it's a mistake to change the thermostat.

 

[96Holly]

I went the elec pump route...

I installed a Meizure electric water pump. I also installed the 160 stat. The 160 only helps when heading down the highway. My coolent temp drops to about 175 down the highway. In traffic I will have to install or reprogram the fans to kick on earlier to get the most out of the pump. As it looks now I can maintain around 190 to 200 in traffic... with the A/C on.

I HIGHLY recomend cleaning between the a/c and rad. Mine was pluged with sand and all kinds of junk from the years past.

 

[boblx2a]

Just putting in a 160 stat is not going to help unless you also change the cut in temp for the fans. If you don't put in a 160 or a a some what lower stat cutting in the fans earlier is going to help, but not near as much. Because you are fighting the stat all the time.
I put in a 180 degree stat and a lower temp sensor switch to cut on the fans earlier. It rarely goes over 200 now because the fans come on at about 190 (both of them) and it starts lowering the temp even in traffic. In the winter that temp is plenty warm enough. A possible down side is a premature failure of the fans.


..................

 

[grapeknutz]

Also the fact that the air is "heated" from the pavment, that alone is 15-20 hotter than air that come in "straight on"

 

[UE19]

I cleaned out all the junk between the radiator. Half the leaves from Washington State were in there. Not to mention tree branches, plastic, gum wrappers. Don't ask me how that got in there. Also changed the anti-freeze and added some waterwetter for kicks. Best mod so far....well besides my 315's on the back.........hehe

 

[Corvette-Pilot]

emissions !