Water Temp Rises 225 during Idle/Traffic

Dr C5 Corvette · 05-23-07, 09:28 AM

Hi, I have noticed my temp Gauge rising to 225-230 during Idle and traffic without the air on. need some suggestions, no codes at this time. How important is the gm coolant . I have topped off with Prestone 50/50 mix a couple of times in the last several months . There is no Order of coolant, could the Stat be going Bad or the cap on the Tank leaking ?............ Thanks Dr C5 Corvette

Ps: I dont here the fans come on with the temp rise only if I have the air on

Hotwing · 05-23-07, 09:54 AM

Mine is the same and I think thats kinda normal in traffic. Check your manual as I think they dictate a certain kind of coolant .....I cant remember off hand

bradfordsvettes · 05-23-07, 03:22 PM

that is the aprox temp that the fans turn on all computer controlled steve

redvett · 05-23-07, 04:38 PM

The stock PCM is set to run the secondary fan at 237F. Nothing is wrong and as long as it toggles between 195F and around 237F your fine . You may want to check & clean the space between the A/C condenser & radiator for leaves & other trash.

zagger · 05-23-07, 05:12 PM

Redvett is absolutly wright

.

As for the coolent only Dexcool should be used.

If you add other type of coolent there can be an a reaction cousing the existing Dex. to jell and plug up the whole system. There has been a lot of threds about the subject, just search this forum.
Good luck.
Zig.

gmjunkie · 05-23-07, 05:54 PM

Quote:

Originally Posted by redvett

The stock PCM is set to run the secondary fan at 237F. Nothing is wrong and as long as it toggles between 195F and around 237F your fine . You may want to check & clean the space between the A/C condenser & radiator for leaves & other trash.

My fans Kick on at 228 if I'm not running the A/C it will creep up tp 232 before comeing back down!!!!

Dr C5 Corvette · 05-24-07, 01:46 AM

Ok I will Look Into that. Maybe I should drain ,flush and fill with new dexcool. where is the drain for the cooling system? Thanks dr C5 Corvette

Dr C5 Corvette · 05-24-07, 01:47 AM

Ok Thanks, that made me feel a lot better Thanks Dr C5 Corvette

Dr C5 Corvette · 06-14-07, 12:10 AM

Ok Drained out most of the old dex cool and refilled with Prestones New GM Approved DEx Cool at a 70% Mix with Distilled Water. Now no more temp rise and stays aroung 197 even in Hot weather and traffic with the air on. I guess the dex cool was diluted to much from previous owner I am HAPPY!!!!! Dr C5 Corvette

fdxpilot · 06-14-07, 01:21 AM

If you have your AC on, the fans will run any time you are under 30 MPH and the coolant temp is over 165. If you turn off your AC, the fans will go off and your temps will rise just like you noted in your first post. At about 228 F (approximately, the temp varies slightly with model year), the fans (both of them) will come on at low speed. At about 235 F, the fans will go to high speed. The temps you mentioned in your post are ops normal for an unmodified C5 cooling system.

redvett · 06-14-07, 10:03 PM

Using a mixture of more water than AF will increase the heat transfer not decrease it. I keep my Corvettes at -15 F and never have heating problems as long as the radiator is clear of debris in front of the condenser and between the condenser & rad.

zagger · 06-14-07, 11:30 PM

Quote:

Using a mixture of more water than AF will increase the heat transfer not decrease it. I keep my Corvettes at -15 F and never have heating problems as long as the radiator is clear of debris in front of the condenser and between the condenser & rad.

Please correct me if I'm wrong, but the modern coolant fluids when mixed in proper ratio with water change the molecular makeup of the fluid. It makes it denser and therefore able to absorb more heat, which makes it more efficient in cooling. The boiling point of water is 212 F. with coolant it is much higher.

TODD L GRIFFITH · 06-15-07, 12:14 AM

There are a few things you can do to drop the temp. For me I have high compression 12.5:1 so I use the 160 degree thermostat and bring the fans on at 180 degrees. This gives me alittle extra protection against detonation. On a hot day I run between 175-185 degrees. Another thing I did was removed the plastic shroud in front of the radiator as well to allow room for my bottom fed Vararam. The extra flow from underneath keeps it cool all summer long. One thing you can do is add the ZO6 grilles in the fog lamp locations. The Gen III's are happy around 190+ anyway. I think the flush did you alot of good. Glycols tend to loose their efficiency after awhile.

redvett · 06-15-07, 10:51 AM

Quote:

Originally Posted by zagger

Please correct me if I'm wrong, but the modern coolant fluids when mixed in proper ratio with water change the molecular makeup of the fluid. It makes it denser and therefore able to absorb more heat, which makes it more efficient in cooling. The boiling point of water is 212 F. with coolant it is much higher.

Water is a much better heat exchanger than a mix of water & AF. The only reason that AF is used is to lubricate,corrosion preventive, and raising the boiling point & freeze protection.
I belong to the ZR-1 Net and we had a engineer at the NCM from GM that explained it all to us way back in 1994 before the LS engines were around.

TODD L GRIFFITH · 06-15-07, 11:03 AM

Quote:

Originally Posted by redvett

Water is a much better heat exchanger than a mix of water & AF. The only reason that AF is used is to lubricate,corrosion preventive, and raising the boiling point & freeze protection.
I belong to the ZR-1 Net and we had a engineer at the NCM from GM that explained it all to us way back in 1994 before the LS engines were around.

I agree 100% this is absolutely correct. I work with alot of different levels of glycol mixtures for anti-freeze protection for building chilled and hot water systems.