I just bought my first Vette, 2004 Zo6 and noticed that in traffic on 85 degree day the car reached 230 degrees. Since this car is new to me I don't know if that is a high temp or not, can anyone answer that? Thank you.

 

Here are the normal turn on temps for the fans:

The low speed cooling fan mode is commanded on when the coolant temperature reaches 226°F. It is turned off if the coolant temperature lowers to 219°F. The high speed cooling fan mode is commanded on when the coolant temperature reaches 235°F. It is turned off if the coolant temperature lowers to 226°F.

When the A/C is on and the coolant temperature reaches 185°F the low speed cooling fan mode will be turned on at vehicle speeds less than 56 kPh (35 mph). Both fans run in either high speed mode or low speed mode.


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I've turned the fans down on my car with hptuners (computer programmer) much lower since I have a 160 degree thermostat.

 

The C5 is cooled in two ways:

1) WHEN THE CAR IS IN MOTION:
Driving above 35 mph air moves up into the ac condenser and radiator. There are black plastic cowlings under your car and if the center piece is missing or heavily damaged the air does not get channeled up into the condenser/radiator and you experience high temperatures.

Also, there are two strips of foam on each side of the AC condenser, those keep air from going around the condenser/radiator instead of thru it. If those are pushed out or missing that can cause you to run about 10 degrees hot.

The AC condenser and Radiator also need to be kept clean, lots of sand, dirt, grass, leaves, plastic bags, etc. get sucked up there and block the movement of air. This is the most common reason a car runs hot while moving.


2) WHEN THE CAR IS STOPPED OR GOING LESS THAN 35MPH.
There are two fans that pull air through the ac condenser/radiator into the engine compartment. The fans have two speeds and there are multiple fuses for the fans in the engine compartment fuse box. You need to verify both fans are running properly, I had a fan fail and I ran about 240 degrees with one fan. If you turn on your AC, it will command the fans to come on. Be very careful when you check the operation of the fans. The fans can be programmed to turn on earlier by a tuner and is the preferred way to cool your car down, vs. installing a tstat.

REVIEW:
So if your car runs 230 when you are in stop and go traffic but you see it drop down to 210 once you get up to 55 mph then you probably have a fan issue. If the car is hot all the time, it's probably an issue with air getting to and thru the radiator.

 

Get yourself a Hypertech programmer and you can adjust the fan temps to come on at the thermostat opening which is 190 degrees. That's what I did and my car now runs between 190 and 200 if I get stuck in traffic.

 

I would also suggest that since you just got the car, take a few minutes and remove the radiator support at the top of the radiator and look between the radiators to see if theres any debris such as paper, plastic bags, leaves, etc that could have gotten sucked into the front-bottom area. Even excessive amounts of dirt!! If so take a hose and spray as much of it out as possible, especially dirt. I cleaned mine a few weeks ago, even removed newspapers, and plastic grocery bags, and now it runs cooler than when I first bought it. Take about 10-15 minutes. Also like another member mentioned, programming the fans to come on sooner couldnt hurt. I also installed a 160 thermostat (about a 10 minute job). You should be okay.

 

The TEMP you are seeing is fine. At 230 the fans kick in and you should your TEMP go down to the 210-220 range. When you are cruising at speeds greater than 35 the TEMPs should go lower.

You could do as others recommend above, but it isn't a must.

 

While 230 is nothing to get worried about, do this ^^ if you want to run cooler. Don't waste your time with a thermostat change.

 

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it will hit 230 in traffic if the ac is off.... if the ac is on the fans start at 210.

 

Just lay down under the front of the car and take compressed air or even a garden hose with a nozzle and wash out the condenser coil, it will make a lot of difference.

 

You might have low coolant.

 

This all sounds pretty normal. Don't waste any money on a low temp t-stat - all that does is open sooner but has no effect on upper end. Keep in mind that the vette has a linear temp gage that shows all the ups and downs in stop and go traffic whereas most vehicles have a center weighted gage that barely moves at all unless there's problem (even tho actual temps are still going up and down). My 03 Z runs 190-200 just cruising down the road.
jcs44

 

I would like to thank everyone for the help.