CCO

CCO

Old Timer
Aug 5, 2011
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Cambridge ON
VetteCoins
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Car
2006 vert, 1994 vert
Anyone have this on their C4 to help with excessive heat?
Apparently it's a switch that can be installed to control the cooling system fan(s) rather than relying on the automatic system to kick in at usually quite high temps.

Thanks.
Colin.
 
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I've come up with what I think is the right wire to splice into for an auxiliary switch:

The secondary fan control is spliced into since the primary will come on first and with the A/C.

Thanks once again Brian.

 
From what I have gathered over the last few weeks it seems that the C4 engines can run quite warm compared to other years, to achieve the correct pollution control and gas mileage.

Added to that the airflow at the front can become restricted with debris causing more heat buildup.
Some folk have added an extra switch to allow more cooling.

Mine doesn't seem to overheat according to what I've seen but I'd like to lower the engine temp a little by adding one of these switches for manual control.

We'll see how it turns out.

C.
 
Would you also have to change the thermostat Colin?

I did change it but a new 180 went in to replace the old one. A lower temp one won't necessarily allow the engine to run cooler -- it'll just open earlier that's all.

What I need is good airflow and better fan cooling to make sure temps don't go too high. -- High enough but not too high and that means keeping the radiator and a/c condenser clean and having the fans kick on earlier.

Don't know if I'm up to doing the fan switch job yet but I'm pretty sure that'll do the trick.

I'll see maybe this week -- the weather looks half decent anyway......Maybe I can gather some inspiration to get it done.

C.
 
My info is do not change the thermostat. The computer system is set up to optimize engine operation with the stock, 190 Tstat. Apparently if you install a lower stat you get other running problems.

I just spent a bag of money to get the heads redone, because of overheat.
While everyone talks about cleaning the airspace at the rad, nobody seems to replace the rad. My thinking is ,after 20 years, how clean can a rad be? My mechanic suggests flushing is a waste of time. Maybe a job for the spring.
 
My info is do not change the thermostat. The computer system is set up to optimize engine operation with the stock, 190 Tstat. Apparently if you install a lower stat you get other running problems.

I just spent a bag of money to get the heads redone, because of overheat.
While everyone talks about cleaning the airspace at the rad, nobody seems to replace the rad. My thinking is ,after 20 years, how clean can a rad be? My mechanic suggests flushing is a waste of time. Maybe a job for the spring.

Sure it's 20 years old or so but to clean it is important and not very easy. My suggestion would be to start there by cleaning properly even if it means removing it from the car and cleaning it.
I personally think removing it from the car is a good investment in time and money.....to make sure it's functioning as it should.
No a thermostat change should not be necessary -- replacement yes but change to a different temp - no, for the reasons you've stated.

It seems to me that for the system to work properly, at least in my C4, needs to be in tip top shape ... ONce age sets in and crud develops both in and out of the radiator and system, it cannot function well enough and will show signs of overheating and sometimes to the point of warping the heads, unfortunately as you have found out.

For me, a complete flush and cleaning both inside and out is in order and will be done next spring as well as a manual control for the fan(s) as an interim solution until that cleaning can come about.

Not sure how my thermostat was changed or if it was changed from a 190 to a 180 -- but if it has been changed, I'm not concerned about a 10 degree change; and nothing that can't be remedied if necessary.

Sorry to hear about your warped heads. Are you sure it was from overheating and did you see the excessive overheating, or are you assuming that that was the problem?

Thanks for sharing your story.

Colin
 
I have the fan switch, comes in handy when cooling down between runs and allows you to keep temps down when getting stuck in traffic.

A good indication of the condition of the cooling system is running the car with the radiator cap off and see if the system is burping or if the level drops. Make sure to pay attention draining fluid to see if there is an rust coming out.
 
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Hi Colin

There was no question on the heads. We got caught in traffic a couple of years back while driving in 100F Temps in Washington. The heat gauge wasn't quite pegged ,but damn near for at least 20 mins. It seemed ok, got us home, but then the next season anti freeze started to disappear but no real signs of head gasket. Long story short is I found A/F in the oil at the end of last year and the shop found a blown head gasket and heads warped. Its been fine since, even with the old rad, but I'm still thinking of a rad replace in the spring.
 
I have a 1996 convertible base model and noticed today while in stop & go traffic (no A/C on) that my coolant temperature got to about 240F.
Questions
1. Do cooling fans only come on when A/C is on?
2. Does anyone know if there is a Auxhilary fan control for a 1996 that doesn't have the check engine light come on? The corvette central part 244455 has this Note: Can be used in 1996 but the "Service Engine Soon" light will come on and a "DTC" will set.
 
Hello DL suggest:
1. check and make sure the air space between the rad and the ac condenser is clear.
2. make sure the rad fins are clean.
3. check that the thermostat is working properly
4. check that the fan relays are working properly
5. confirm there are no leaks
6. monitor your anti freeze levels, if it seems to disappear but no outside leakage, might be head gasket.
7 If all is well, (it probably is), then , before you go messing about with switches and t'stats and relays, put a new , stock rad in it.
Seems to me everyone (me included) overlooks this component. Logic dictates the rad is over 20 years old, they scale up.
It was the best thing I've ever done to the car. I did the work, its time consuming and has some awkward screws, but with some patience ,its doable.
A rad only cost $250.00 and my heat gauge hasn't gone past 1/2 since.
By the way the stock rad idea was suggested to me by Manny Dasilva Dasilva Motorsports.
 
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