Coolant Change Question
Thread Starter
Advanced
Joined: Dec 2004
Posts: 67
Likes: 0
Coolant Change Question
I just finished changing my coolant. Topped up the reservoir and ran with the cap off and then on. Can't seem to get the temp. below 210. I assume there is air in the system somewhere.
Any tips on how to solve this problem?
Also, the drain valve --- In reading other threads, I assumed that you turned the white nylon plug on the (as you face the car from the front) lower left corner of the radiator. It turns out that this plug/valve pulls out (toward the rear of the car). What is to prevent this from moving as the vehicle is operating?
Thanks.
Any tips on how to solve this problem?
Also, the drain valve --- In reading other threads, I assumed that you turned the white nylon plug on the (as you face the car from the front) lower left corner of the radiator. It turns out that this plug/valve pulls out (toward the rear of the car). What is to prevent this from moving as the vehicle is operating?
Thanks.
Safety Car
Joined: Aug 2000
Posts: 4,933
Likes: 30
From: San Rafael CA
I just finished changing my coolant. Topped up the reservoir and ran with the cap off and then on. Can't seem to get the temp. below 210. I assume there is air in the system somewhere.
Any tips on how to solve this problem?
Also, the drain valve --- In reading other threads, I assumed that you turned the white nylon plug on the (as you face the car from the front) lower left corner of the radiator. It turns out that this plug/valve pulls out (toward the rear of the car). What is to prevent this from moving as the vehicle is operating?
Thanks.
Any tips on how to solve this problem?
Also, the drain valve --- In reading other threads, I assumed that you turned the white nylon plug on the (as you face the car from the front) lower left corner of the radiator. It turns out that this plug/valve pulls out (toward the rear of the car). What is to prevent this from moving as the vehicle is operating?
Thanks.
The drain valve is only meant to be opened 90 degrees (a quarter turn) then pulled out. To close the valve you push it back in and turn it closed 90 degrees. If you turned it too far when opening it you have damaged the tabs that hold the drain valve in the radiator.
Team Owner
Joined: Dec 1999
Posts: 174,312
Likes: 1,216
From: Here
Pilot of Beer Force 1
Tampa Regional Coordinator
CI 4-5-6-7-8 Veteran
Organizer St. Jude Fundraiser
I believe in the Beer Fairy
pull the hose loose and drain some coolant off at the stat....makes a mess but.....
Pro
Joined: Aug 2006
Posts: 565
Likes: 2
From: Chattanooga TN
...to bleed the system when refilling, here is a trick. The coolant line that goes from the intake to the radiator can be disconnected at the intake side and suspended with the hole facing up.
As you refill the cooling system, most (if not all) of the air will be forced out that hole.
You can also run the engine with the cap off of the coolant fill tank, but you have to keep a close eye on it if it starts to bubble coolant out.
Thread Starter
Advanced
Joined: Dec 2004
Posts: 67
Likes: 0
Update
I drove the car for about 15 minutes and the temp stayed around 206 -209. When I returned home, I let it idle and the temp crawled up to 220 at which point I turned it off. After it cooled, I checked the reservoir and it was still full.
Any other ideas on how to burp this thing?
Any other ideas on how to burp this thing?
Le Mans Master
Joined: Feb 2002
Posts: 6,937
Likes: 21
From: Waldorf MD
The shop manual says to full it up three times. Each time, alternately rev to 3,000 rpm until temperature reaches 210 F. Then CAREFULLY remove cap and repeat. Last time fill to 1/2 inch above cold mark.
This is NOT like the C4, you won't get trapped air.
This is NOT like the C4, you won't get trapped air.
Burning Brakes
Joined: Sep 2007
Posts: 1,048
Likes: 300
From: FL
I drove the car for about 15 minutes and the temp stayed around 206 -209. When I returned home, I let it idle and the temp crawled up to 220 at which point I turned it off. After it cooled, I checked the reservoir and it was still full.
Any other ideas on how to burp this thing?
Any other ideas on how to burp this thing?
Was the AC on or not when it was 220? Without AC, the fan does not come on until 226, 2nd fan at 235. With the AC at idle, it usualy won't go much above 205-210 since the low speed fan is on.
The correct procedure is to bring it up to 212 and then carefully let it "burp" by releasing the cap slowly. If you do a search you will find the actual procedure from the shop manual.
Good luck.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
2027 Corvette vs The World: Every Model vs Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)
Joe Kucinski
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!
Michael S. Palmer
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!
Joe Kucinski
Safety Car
Joined: Aug 2000
Posts: 4,933
Likes: 30
From: San Rafael CA
.... It is not trapped air.I already asked the OP above ....
Why did you change the coolant .... was the system running at 210 before the change ????
Has the OP checked under the front airdam for debris in the front of the A/C condenser ???
Has the OP checked the upper and lower radiator hose temperatures to ensure proper coolant circulation ???
Is the center airdam correctly in place ????
What is the oil temperature when the coolant temperature is running at 210 ???
We'll see if I get a response this time.
Safety Car
Joined: Aug 2000
Posts: 4,933
Likes: 30
From: San Rafael CA
Was the AC on or not when it was 220? Without AC, the fan does not come on until 226, 2nd fan at 235. With the AC at idle, it usualy won't go much above 205-210 since the low speed fan is on.
The correct procedure is to bring it up to 212 and then carefully let it "burp" by releasing the cap slowly. If you do a search you will find the actual procedure from the shop manual.
Good luck.
The correct procedure is to bring it up to 212 and then carefully let it "burp" by releasing the cap slowly. If you do a search you will find the actual procedure from the shop manual.
Good luck.
Also driving the car "burps" the cooling system through the air bleed pipes .... often referred to as the "steam" pipes on top of the engine.
He doesn't need to "burp" the system ... he's most likely got some other problem.
Le Mans Master
Joined: Feb 2002
Posts: 6,937
Likes: 21
From: Waldorf MD
There is nothing wrong with running at 210 F !
Corvette Cooling Fans Operation
The low speed cooling fan is commanded on when the coolant temperature reaches 108°C (226°F). It is turned off if the coolant temperature lowers to 104°C (219°F). The high speed cooling fan is commanded on when the coolant temperature reaches 113°C (235°F). It is turned off if the coolant temperature lowers to 108°C (226°F). When the A/C is on and the coolant temperature reaches 85°C (185°F), the low speed cooling fan will be turned on at vehicle speeds less than 56 kPh (35 mph).
Corvette Cooling Fans Operation
The low speed cooling fan is commanded on when the coolant temperature reaches 108°C (226°F). It is turned off if the coolant temperature lowers to 104°C (219°F). The high speed cooling fan is commanded on when the coolant temperature reaches 113°C (235°F). It is turned off if the coolant temperature lowers to 108°C (226°F). When the A/C is on and the coolant temperature reaches 85°C (185°F), the low speed cooling fan will be turned on at vehicle speeds less than 56 kPh (35 mph).
Thread Starter
Advanced
Joined: Dec 2004
Posts: 67
Likes: 0
More Info
I changed the coolant because it is 7 years old.
I'm unsure of coolant temp before change - I rarely read it on the DIC but the temp needle is where it usually is on the gauge.
The A/C condenser coil had a small amount of debris that I vacuumed off.
Both the supply and return hoses were hot to the touch.
The center of the air dam is scuffed but largely intact.
When the coolant temp is 210 the oil temp is 199.
Ambient temp is 70.
The card drives ok temp wise - it's just when I idle it that it starts to creep up.
BTW, how high would you let the temp go before shutting the car down?
Thanks for everyone's input. It is much appreciated.
I'm unsure of coolant temp before change - I rarely read it on the DIC but the temp needle is where it usually is on the gauge.
The A/C condenser coil had a small amount of debris that I vacuumed off.
Both the supply and return hoses were hot to the touch.
The center of the air dam is scuffed but largely intact.
When the coolant temp is 210 the oil temp is 199.
Ambient temp is 70.
The card drives ok temp wise - it's just when I idle it that it starts to creep up.
BTW, how high would you let the temp go before shutting the car down?
Thanks for everyone's input. It is much appreciated.
Safety Car
Joined: Aug 2000
Posts: 4,933
Likes: 30
From: San Rafael CA
How come no one reads the Owner's Manual for these cars ..... go to the Index and look up ENGINE, sub-category "Overheated Engine Protection Operating Mode"
You can drive the car at least 50 miles with NO (Zero ... None ... Nada ... Zilch) coolant in the system when the engine goes into this "Limp Home" mode .....
As Oldvetter points out, your car is operating within the "normal" range of coolant temperatures.
As Bugs Bunny would say .... "unlax", there is nothing to worry about.
You can drive the car at least 50 miles with NO (Zero ... None ... Nada ... Zilch) coolant in the system when the engine goes into this "Limp Home" mode .....
As Oldvetter points out, your car is operating within the "normal" range of coolant temperatures.
As Bugs Bunny would say .... "unlax", there is nothing to worry about.
Thread Starter
Advanced
Joined: Dec 2004
Posts: 67
Likes: 0
Update
I'm still running 220 when idling. I know everyone said don't worry but after 10 minutes of idling today I noticed a small amount of coolant under the car. I couldn't tell where it was coming from. The fan was also running and it has never done this in the past. I'm a little worried when the ambient temp hit 95 this summer.
I know I'm being the guy who asks for advice and then questions the advice -
but I would hate to burn up a perfectly good engine because I missed something.
Thanks again, everyone!
I know I'm being the guy who asks for advice and then questions the advice -
but I would hate to burn up a perfectly good engine because I missed something.Thanks again, everyone!
Burning Brakes
Joined: Jan 2006
Posts: 1,226
Likes: 45
From: Castleton VA
Cruise-In VIII Veteran
I'm still running 220 when idling. I know everyone said don't worry but after 10 minutes of idling today I noticed a small amount of coolant under the car. I couldn't tell where it was coming from. The fan was also running and it has never done this in the past. I'm a little worried when the ambient temp hit 95 this summer.
I know I'm being the guy who asks for advice and then questions the advice - but I would hate to burn up a perfectly good engine because I missed something.
Thanks again, everyone!
I know I'm being the guy who asks for advice and then questions the advice -
but I would hate to burn up a perfectly good engine because I missed something.Thanks again, everyone!
As to the coolant dropping, was the coolant at the center? under the engine? under the radiator? off to one side near a wheel (i.e., under the recovery tank)? Did you spill any during refill that may have finally found its way to the ground? Lastly, have you taken a flash light and poked around the water pump for tell-tale signs of a leaking pump? Could be the coolant on the ground is just a coincidence, and from an source unrelated to the coolant change.
HTH,
Mark
Racer
Joined: Apr 2002
Posts: 274
Likes: 0
From: tarentum pa
like blackz06 said, there is no need to burp the cooling system. if you feel you must to put your mind at ease, disconnect the coolant return hose from the throttle body. This will enable the entire system to be purged manually. Reconnect the hose and close the valve when you see a drop of coolant come out.
Tech Contributor
Joined: Oct 1999
Posts: 40,995
Likes: 9,759
From: Charlotte, NC (formerly Endicott, NY)
I'm still running 220 when idling. I know everyone said don't worry but after 10 minutes of idling today I noticed a small amount of coolant under the car. I couldn't tell where it was coming from. The fan was also running and it has never done this in the past. I'm a little worried when the ambient temp hit 95 this summer.
I know I'm being the guy who asks for advice and then questions the advice - but I would hate to burn up a perfectly good engine because I missed something.
Thanks again, everyone!
I know I'm being the guy who asks for advice and then questions the advice -
but I would hate to burn up a perfectly good engine because I missed something.Thanks again, everyone!
Bill
Tech Contributor
Joined: Dec 2003
Posts: 19,384
Likes: 87
From: Horncastle Lincolnshire, England
2023 C5 of the Year Finalist - Unmodified
