C5 Coolant Temp.
Thread Starter
3rd Gear
Joined: Jan 2019
Posts: 3
Likes: 0
C5 Coolant Temp.
i just bought a c5 about 3 days ago and im super hyped about it, but i notice the tempreture gauge is all over the place. Average coolant temp is about 220-230 but its went up to 236 and i just want to know if i should get it looked at or if this is normal
Drifting
Joined: Sep 2009
Posts: 1,862
Likes: 594
From: Prescott, Arizona
What are the circumstances that you are seeing these temperatures? Highway speed temperatures are lower than you report, 190- 200 but temperatures often go higher idling in traffic to the levels you report.
Are the fans coming on?
=left
Factory settings to turn on the cooling fans is ON at 226 degrees in low speed mode (both fans run but are electrically configured in series so that each fan has about 1/2 of battery volts across each motor so at slower than rated speed). Fans go off at 219 degrees or once the vehicle speed exceeds 35mph. If the coolant temp kept going up the fans go into high speed mode at 235 degrees. In high speed mode the electrical configuration is changed from series to parallel. In parallel mode both fans have the full battery voltage across each fan motor so they run at full rated speed. They revert to low speed mode once the coolant temp reaches 226 degrees..=left
Are the fans coming on?
=left
Factory settings to turn on the cooling fans is ON at 226 degrees in low speed mode (both fans run but are electrically configured in series so that each fan has about 1/2 of battery volts across each motor so at slower than rated speed). Fans go off at 219 degrees or once the vehicle speed exceeds 35mph. If the coolant temp kept going up the fans go into high speed mode at 235 degrees. In high speed mode the electrical configuration is changed from series to parallel. In parallel mode both fans have the full battery voltage across each fan motor so they run at full rated speed. They revert to low speed mode once the coolant temp reaches 226 degrees..=left
Drifting
Joined: Sep 2009
Posts: 1,862
Likes: 594
From: Prescott, Arizona
Well that came out as gibberish-
Factory settings to turn on the cooling fans is ON at 226 degrees, both fans run on low. If temperature drops to 219 degrees the fans go off. Fans also go off at speeds over 35 MPH.
If coolant temp rises to 235 degrees the fans go ON in high mode, and if the coolant temp drops to 226 degrees the fans revert to low speed.
Factory settings to turn on the cooling fans is ON at 226 degrees, both fans run on low. If temperature drops to 219 degrees the fans go off. Fans also go off at speeds over 35 MPH.
If coolant temp rises to 235 degrees the fans go ON in high mode, and if the coolant temp drops to 226 degrees the fans revert to low speed.
Thread Starter
3rd Gear
Joined: Jan 2019
Posts: 3
Likes: 0
Well that came out as gibberish-
Factory settings to turn on the cooling fans is ON at 226 degrees, both fans run on low. If temperature drops to 219 degrees the fans go off. Fans also go off at speeds over 35 MPH.
If coolant temp rises to 235 degrees the fans go ON in high mode, and if the coolant temp drops to 226 degrees the fans revert to low speed.
Factory settings to turn on the cooling fans is ON at 226 degrees, both fans run on low. If temperature drops to 219 degrees the fans go off. Fans also go off at speeds over 35 MPH.
If coolant temp rises to 235 degrees the fans go ON in high mode, and if the coolant temp drops to 226 degrees the fans revert to low speed.
Safety Car
Joined: Jan 2015
Posts: 3,830
Likes: 394
From: Rocky Mountains
It's normal for it to fluctuate a lot. Right now in the winter, my water temp varies from 185 (cruising at high speed on the freeway) to 220 (stop and go traffic). But 236 is abnormally high unless you have extremely hot ambient temperatures. (like Las Vegas or Death Valley in the summer, 110-120 degrees)
The only time I ever saw my water temp get that high is when it was like 118 outside.
Check your radiator fins for debris. Also it wouldn't hurt to change the coolant.
The only time I ever saw my water temp get that high is when it was like 118 outside.
Check your radiator fins for debris. Also it wouldn't hurt to change the coolant.
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Drifting
Joined: Nov 2016
Posts: 1,660
Likes: 365
From: SF Bay Area
Hot weather in stop and go traffic, 236 is highly possible and technically within normal operating spec of the C5. If you're seeing more than 210 while cruising down the freeway (65+ mph consistent), I would check for a blocked radiator.
Pro
Joined: Jan 2005
Posts: 644
Likes: 17
From: O'Fallon MO
Mike
Last edited by mhanley; Jan 13, 2019 at 12:12 PM.
Team Owner
Joined: Oct 1999
Posts: 31,976
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From: Guinness Its whats for B'fast JAWGA
CI 3-4-5-9 Veteran
as well, get it up in the air and see what comes out. If it persists I would pull the radiator shroud to gain better access and then use compressed air to blow out the fins. If you decide to replace the thermostat, I would absolutely pull the shroud and move the radiator around if not pull it and blow compressed air through all of the fins. It is amazing how much can get stuck in the radiator with it being a bottom feeder.
Tech Contributor
Joined: Oct 1999
Posts: 41,042
Likes: 9,805
From: Charlotte, NC (formerly Endicott, NY)
Your car is between 15 and 22 years old so there can be a lot of debris in the cooling path. If there is a lot of dirt/debris in front of the AC condenser you may need to pull the radiator to can gain access to the back side of the AC condenser so you can use compressed air to blow out the condenser. If you have the radiator out sometimes it is effective to hold it in a horizontal position with the front of the radiator down about a foot off the floor and let it drop. The shock will knock out a lot of debris that gets embedded deep in the fins. Sometimes works better than using water or compressed air. One other thing that you should check are the seals between the AC condenser and the radiator. Those seals prevent air from escaping into the engine compartment without going through the radiator. You may notice them sticking out of the side of the shroud when the hood is open or after all this time they may be gone. I owned a 97 for 6 years followed by an 03 Z06 for 6 years and those seals were a problem on both cars. On the 97 they blew out after about 5000 miles and that was when the car was new not old with rotted seals.
Bill
Bill
Last edited by Bill Dearborn; Jan 14, 2019 at 02:40 PM.
Drifting
Joined: Jul 2015
Posts: 1,844
Likes: 375
From: San Jose, CA
Clean the radiator fins!
Bring it to a shop (or do it yourself) - Get it on a lift, and use compressed air to blow through the radiator, back to front. Give 'er a real good blast, and more, and then like ten times more.
A car that hasn't had its radiator fins blasted can be a solid 30F hotter than a car that has. When the temps are cold and you're cruising fast at low rpm, it might not show at all, but try idling the car when it's 100F outside, yeah? If it goes up, and up, and up, and up, and hits 240+, it's almost certain your cooling is not working as intended from the factory.
Bring it to a shop (or do it yourself) - Get it on a lift, and use compressed air to blow through the radiator, back to front. Give 'er a real good blast, and more, and then like ten times more.
A car that hasn't had its radiator fins blasted can be a solid 30F hotter than a car that has. When the temps are cold and you're cruising fast at low rpm, it might not show at all, but try idling the car when it's 100F outside, yeah? If it goes up, and up, and up, and up, and hits 240+, it's almost certain your cooling is not working as intended from the factory.