Adjusting Cooling Fans - C6 - Calgary

[Messner]

I have a 2007 C6 Base Auto.
When it’s into the low mid 20’s and higher and I’m driving slow in town or in “slow” traffic my coolant temps get up to 235 maybe even 240.

I’ve cleaned out my radiator fins and those of the condenser too. (I made a tool to blow them out/clean them from the back with a garden hose attachment).

I’m going on the Corvette Caravan in August to Kentucky and wondering what it will be like down south in their hot temps and in the traffic of the Caravan.

I ran into a guy on Kijiji (Bill Fischer) from here in Calgary who says he can re-program the Cooling fans to come on (earlier) partially at 93C and then full on at 97C.

I’ve read elsewhere that a lot of guys do this with their tuning. Mine is bone stock.

Anyone have any C6 experience with this type of adjustment?

Does this sound like a proper fix to you?

Thanks in advance!!

Jim

 

[Rruuff Day]

I have a 2007 C6 Base Auto.
When it’s into the low mid 20’s and higher and I’m driving slow in town or in “slow” traffic my coolant temps get up to 235 maybe even 240.

I’ve cleaned out my radiator fins and those of the condenser too. (I made a tool to blow them out/clean them from the back with a garden hose attachment).

I’m going on the Corvette Caravan in August to Kentucky and wondering what it will be like down south in their hot temps and in the traffic of the Caravan.

I ran into a guy on Kijiji (Bill Fischer) from here in Calgary who says he can re-program the Cooling fans to come on (earlier) partially at 93C and then full on at 97C.

I’ve read elsewhere that a lot of guys do this with their tuning. Mine is bone stock.

Anyone have any C6 experience with this type of adjustment?

Does this sound like a proper fix to you?

Thanks in advance!!

Jim

In my opinion that's pretty hot. My C6 seldom passed 200 degrees. The most I ever saw in traffic on a hot day was 210. If it were me, I'd flush my coolant system. Drain the sytem at the rad drain valve, shut the valve and add clear water and run the car until hot. Drain again and repeat until all the coolant is gone and it runs clear when you drain. Then refill with a 60/40 or 70/30 mix of coolant and water. Water, although it cools better than coolant, has a much lower boiling point than coolant and is quite corrosive, and it will also freeze, thus the mixture. It is also possible your thermostat is sticking and allowing the temp to rise too much before it opens.

 

[Messner]

In my opinion that's pretty hot. My C6 seldom passed 200 degrees. The most I ever saw in traffic on a hot day was 210. If it were me, I'd flush my coolant system. Drain the sytem at the rad drain valve, shut the valve and add clear water and run the car until hot. Drain again and repeat until all the coolant is gone and it runs clear when you drain. Then refill with a 60/40 or 70/30 mix of coolant and water. Water, although it cools better than coolant, has a much lower boiling point than coolant and is quite corrosive, and it will also freeze, thus the mixture. It is also possible your thermostat is sticking and allowing the temp to rise too much before it opens.

Thanks for the reply. I often wondered what others like mine were running at for temps. Yes I’ve been thinking of doing those things too. This morning idling in the garage at 17C Out it’s hitting 102C (216F) Not very hot outside.

 

[MikeysZ06]

I’ll post my running temps this weekend. I think I run similar to what Eric’s ran albeit a bigger motor. Just a hair below 200 maybe. Has me curious now.

 

[Cariboocreek]

Thanks for the reply. I often wondered what others like mine were running at for temps. Yes I’ve been thinking of doing those things too. This morning idling in the garage at 17C Out it’s hitting 102C (216F) Not very hot outside.

Jim, I have never hit 95c. Even today idling around Airdrie saw 93 max.

 

[Messner]

Jim, I have never hit 95c. Even today idling around Airdrie saw 93 max.

Thanks Bud! If I recall yours is the 6.2L am I right?
- Same day as yours I was 91C on the highway.
- Around town with a daytime temp of 22C and in stop & go traffic I was 101 and it went to 106 when I parked. At that point my fans came on. Are their any stock 6 Liter Cars out there running this hot??

This has now become the question so I think I know what I’m working on this weekend - haha!

 

[Cariboocreek]

Thanks Bud! If I recall yours is the 6.2L am I right?
- Same day as yours I was 91C on the highway.
- Around town with a daytime temp of 22C and in stop & go traffic I was 101 and it went to 106 when I parked. At that point my fans came on. Are their any stock 6 Liter Cars out there running this hot??

This has now become the question so I think I know what I’m working on this weekend - haha!

I have an LS3 6.2. The Grand Sport has the additional oil cooler as well. I run on the highway water temp of about 85 and oil temp of 75, on a 25c day. In town max of 95 water and I have seen 90 oil temp.

I am not smart enough to say definitively, but it strikes me that you are running a little warm.

 

[Messner]

I have an LS3 6.2. The Grand Sport has the additional oil cooler as well. I run on the highway water temp of about 85 and oil temp of 75, on a 25c day. In town max of 95 water and I have seen 90 oil temp.

I am not smart enough to say definitively, but it strikes me that you are running a little warm.

I think so? Not real bad but don’t wanna take any chances. That extra oil cooler you have helps. I don’t have one as it’s a Base. I know these things are made to run hotter than my old Chevy small blocks and running these things too cool will create other issues. But I think I’ll knock it down a bit for the Kentucky run etc!

 

[henkz06]

You could try a cooler 160 degree thermostat.

 

[Messner]

You could try a cooler 160 degree thermostat.

Been thinking about that too... Thanks!

 

[Keith Tedford]

Has anyone tried this waterless coolant from Evans? A rad flush and fresh regular antifreeze has worked for us so far but the Evans coolant has me interested. Amazon product ASIN B00TPVI2TQ

 

[ddgermann]

Has anyone tried this waterless coolant from Evans? A rad flush and fresh regular antifreeze has worked for us so far but the Evans coolant has me interested. Amazon product ASIN B00TPVI2TQ

I converted my H1 Hummer to Evans. Night and day in running temperatures under load or in stop and go traffic. Dropped my temperatures and now pulling my RZR in the mountains the temp rarely reaches 200. The cooling system on my Hummer runs at 0 pressure now as well. Part of the requirement for Diesel engines. Not sure about gas engines. My coolant cap was modified to not hold pressure. I get a bit of a coolant smell occasionally as a result but not a drop has been lost in 4 years or so.
It’s expensive to switch over as the system has to be flushed with an Evans flush liquid to get out all the water and old coolant before you actually dump in the waterless stuff. The stuff boils at 300 C or something ridiculous like that. It’s been a few years so can’t quite remember.
It’s very popular for high performance gas engines as well.
If you do change over be sure and get a couple extra jugs of if it as it cannot be mixed with water or any other coolant if you lose a hose or something. This stuff is not available along the highway service stations.

Hope that helps.

 

[MikeysZ06]

Tonight westbound Hwy 1 with no AC on. Outside temp was 21.

 

[Messner]

Tonight westbound Hwy 1 with no AC on. Outside temp was 21.

View attachment 29739

Mines about the same on the highways. It’s when I’m in town during stop and go traffic that it gets hotter. Thanks!!

 

[Messner]

The saga continues!

It’s getting close and I’m Excited & Getting ready for the Corvette Caravan to Kentucky!

Decided to do the thermostat next.
I decided not to go with the 160 degree thermostat that some use when they do tunes.
I went with a stock AC Delco - 86C (187F) thermostat (from Shaganappi Chev in Calgary) which was $100.00 cheaper than a local shop quoted in Cochrane (yes you read that right - crazy!).

1. First I checked it to make sure it was opening properly in a pot of boiling water and yes it was.
2. Next I ran the car up on ramps and drained the radiator.
3. Pulled the old thermostat out and replaced it with my new “made in Japan” AC Delco model.

Both the drain plug (bottom right of Rad - finger tight) and the thermostat housing were easy to get at!

Buttoned it all back up.
Refilled her with Dex Cool and burped her several times to make sure no air was caught up inside.
The coolant looked brand new and clean so I didn’t replace it (bought car last year and didn’t know if anyone ever changed coolant but it looked good and clean.).

Tools Needed:
1. Water Pump Pliers in case you need to move hose clamp.
2. Straight blade screw driver for a/a.
3. 10 mm socket on wobbly short extension.

Checked in with a friendly GM Mechanic who got me these numbers for a 6 Liter, 2007 model:
1. Thermostat should start opening at 87C/187F.
2. Low fan should come on at 95C/203F.
3. High fan should come on at 113C/235F.
4. Warning lights on dash at 125C/257F (scary hot!).

New Temps Mine Runs At Now:
- Highway 196F/91C at 100Kph @ 72F ambient temp.
- Heavy stop & go traffic - 217F/102C Maximum @ 72 ambient.
- Needs approx 40kph to start Cooling via incoming air (With Vararam Snake Charmer CAI).

Now it’s running much cooler. My biggest issue was heavy stop and go traffic in town.
Kentucky will be hot and I’m sure we will have heavy traffic in the Caravan!

It’s an easy job and I wouldn’t hesitate to do it again.
I was surprised - Easy to get at (than I thought it would would be) what you need to.

I hope this helps someone else to do your own (easy)!

Saved at least $350.00 as that same shop in town here wanted to flush it too and you guessed it - it did NOT need a flush! - Hope this helps someone else too! - Love my Vette!!!

 

[ByronF]

Glad to see that you have hopefully corrected the problem of running hot. I used to have a similar problem on my 2005 SSR with the 6L LS2 motor. I replaced the the thermostat, flushed the cooling system and installed a new aftermarket shrouded fan that moved 30% more cfm. While all these things helped improve the situation there were still days when it would run hot in stop and go traffic. The temp cure believe it or not was to turn on the a/c to max and this would kick the fan in right away and start to cool the motor down. I talked to various GM dealers about changing the settings for when the fan kicks in but they apparently cannot do it because of the software they get from GM. The only real cure was to find a tuner that could reprogram the controller so the fan kicks in at a lower temp. If all else fails you may want to consider this option.

 

[Cariboocreek]

Glad to see that you have hopefully corrected the problem of running hot. I used to have a similar problem on my 2005 SSR with the 6L LS2 motor. I replaced the the thermostat, flushed the cooling system and installed a new aftermarket shrouded fan that moved 30% more cfm. While all these things helped improve the situation there were still days when it would run hot in stop and go traffic. The temp cure believe it or not was to turn on the a/c to max and this would kick the fan in right away and start to cool the motor down. I talked to various GM dealers about changing the settings for when the fan kicks in but they apparently cannot do it because of the software they get from GM. The only real cure was to find a tuner that could reprogram the controller so the fan kicks in at a lower temp. If all else fails you may want to consider this option.

My 95 z28 runs warm and exactly the same thing, turn on the AC and the temps drop considerably.

 

[Messner]

Glad to see that you have hopefully corrected the problem of running hot. I used to have a similar problem on my 2005 SSR with the 6L LS2 motor. I replaced the the thermostat, flushed the cooling system and installed a new aftermarket shrouded fan that moved 30% more cfm. While all these things helped improve the situation there were still days when it would run hot in stop and go traffic. The temp cure believe it or not was to turn on the a/c to max and this would kick the fan in right away and start to cool the motor down. I talked to various GM dealers about changing the settings for when the fan kicks in but they apparently cannot do it because of the software they get from GM. The only real cure was to find a tuner that could reprogram the controller so the fan kicks in at a lower temp. If all else fails you may want to consider this option.

Thanks! I found a guy in Calgary that will re program the fans for the price of the software license which is $100 USD. Not sure I want to mess with that tho? These cars normally run hotter than the good ole small block Chevys. I think I’m in the range the Engineers designed her for now. I have used the A/C trick in the past and it helps too!

 

[Lanster]

Thanks guys for your replies, I apreciate all the info.yes these Temps seem high to me as well.I have flushed and changed the coolant with a high quality product and the thermostat.since my last message.the car still wants to run pretty warm in town.I will try that a trick , the low speed fan does work, I would like to know what the high speed temp is.Im kinda paranoid with this running temp being an aluminium engine.yes these newer engines run hotter, such as the kenworth I have runs around 200 f and the fan engages at 205.
Yaa I'm comparing apples to oranges !thanks again for all yall ! Info !,

 

[Rruuff Day]

From what I have read up on, Jim is spot on. Unless the AC is turned on, the high speed fan should come on at 235 degrees. Turning the AC on to max will kick the fan into high speed considerably sooner.