Engine Overheating
Le Mans Master
Joined: Jul 2002
Posts: 7,370
Likes: 8
From: Slave to the evil empire
Cruise-In V Veteran
St. Jude Donor '04
You need to check the thermostat or just replace it.
When you remove the thermostat the coolant doesn't spend enough time in the radiator to actually cool off, so the coolant is constantly circulating and building heat, getting hotter with each pass thru the engine and only cooling slightly with each pass thru the radiator.
When you remove the thermostat the coolant doesn't spend enough time in the radiator to actually cool off, so the coolant is constantly circulating and building heat, getting hotter with each pass thru the engine and only cooling slightly with each pass thru the radiator.
Drifting
Joined: Oct 2002
Posts: 1,773
Likes: 66
From: SoCal
This was my first thought when I opened this thread. If not getting heat then the core is not getting hot water to give you the heat. Had 2 cars in the past with this problem. Not sure how the plumbing in the C5 is. Just thinking there is a blockage that is causing both the flow for cooling as well as the heater core.
Drifting
Joined: Oct 2002
Posts: 1,773
Likes: 66
From: SoCal
You need to check the thermostat or just replace it.
When you remove the thermostat the coolant doesn't spend enough time in the radiator to actually cool off, so the coolant is constantly circulating and building heat, getting hotter with each pass thru the engine and only cooling slightly with each pass thru the radiator.
When you remove the thermostat the coolant doesn't spend enough time in the radiator to actually cool off, so the coolant is constantly circulating and building heat, getting hotter with each pass thru the engine and only cooling slightly with each pass thru the radiator.
Le Mans Master
Joined: Jul 2002
Posts: 7,370
Likes: 8
From: Slave to the evil empire
Cruise-In V Veteran
St. Jude Donor '04
This was my first thought when I opened this thread. If not getting heat then the core is not getting hot water to give you the heat. Had 2 cars in the past with this problem. Not sure how the plumbing in the C5 is. Just thinking there is a blockage that is causing both the flow for cooling as well as the heater core.
If you can select full heat inside the car and it does not blow hot air then it could be a bad water pump but the water pump is so simple in it's operation I just have a hard time believing that.
Drifting
Joined: Oct 2002
Posts: 1,773
Likes: 66
From: SoCal
The hot water is pumped directly from the water pump to the heater core and from the heater core it is rounted right back to the water pump, you can see 3 hoses on the right side of the water pump, the 2 small ones are heater hoses and the large one is the lower radiator hose.
If you can select full heat inside the car and it does not blow hot air then it could be a bad water pump but the water pump is so simple in it's operation I just have a hard time believing that.
If you can select full heat inside the car and it does not blow hot air then it could be a bad water pump but the water pump is so simple in it's operation I just have a hard time believing that.
Thanks for the info. Well then the heat problem in the car is probably something that can be read through codes for the HVAC maybe. I don't see the Heater core being an issue. I guess you can feel for temp changes in the two heater hoses into the water pump to make sure hot water is going through there. eliminates any heater core issues in his heating problem. Thought the overheating issue and the heating problem were a combined problem but maybe not.
Thread Starter
Intermediate
Joined: Aug 2005
Posts: 28
Likes: 0
I tried blowing into one of the small top hoses on the radiator with the drain plug out and it seems that something is blocking it. I blowed in the big hose on the top left for the radiator and I blew through fine. I am thinking that the radiator is cloged. I am thinking of getting a new radiator and installing it. I think the waterpump is fine and trying to pump I just think that the radiator is cloged. I did open the cap a little after running the car for a while and it does have pressure. When I opened it a little a lot of steam came out and it was relieving the pressure.
What do yall think? I am guessing radiator.
What do yall think? I am guessing radiator.
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Le Mans Master
Joined: Feb 2002
Posts: 6,937
Likes: 21
From: Waldorf MD
loosen the bottom radiator hose, if water flows from the top radiator hose to the bottom freely, then I doubt your radiator is clogged.
It really sounds like a bad water pump. Did you have heat recently?
It really sounds like a bad water pump. Did you have heat recently?
Thread Starter
Intermediate
Joined: Aug 2005
Posts: 28
Likes: 0
I had heat tuesday morning by tuesday afternoon the car started to overheat. I was told that it might be the radiator because it had almost 90k miles and I had never changed the dexcool. Someone told me that the dexcool caused a lot of clogging.
Race Director
Joined: Jan 2006
Posts: 10,554
Likes: 33
From: Not on either liberal coast.
The DEXCOOL naysayers are at it again...read all of this...
http://forums.corvetteforum.com/show....php?t=1887144
http://forums.corvetteforum.com/show....php?t=1887144
Tech Contributor
Joined: Jan 2007
Posts: 19,362
Likes: 1,128
From: Dyer, IN
You need to check the thermostat or just replace it.
When you remove the thermostat the coolant doesn't spend enough time in the radiator to actually cool off, so the coolant is constantly circulating and building heat, getting hotter with each pass thru the engine and only cooling slightly with each pass thru the radiator.
When you remove the thermostat the coolant doesn't spend enough time in the radiator to actually cool off, so the coolant is constantly circulating and building heat, getting hotter with each pass thru the engine and only cooling slightly with each pass thru the radiator.
Last edited by lucky131969; Dec 18, 2007 at 06:39 PM.
Thread Starter
Intermediate
Joined: Aug 2005
Posts: 28
Likes: 0
Ok problem may be resolved. Yesterday I replaced the thermostat. While I was at autozone the guy there told me to make sure that I "Burp" the car. He said that when you drain the whole system there is air in the engine. I thought I got all the air out after running it for a while. Everything seemed fine. I ran the car yesterday night and it overheated on the highway. I was only 15 min away from my house but took nearly an hour to get home. I would drive it a little and then wait for the car to cool down. I got home and parked it for the night. The next day I woke up and checked the resivior. The resivior was completely empty. I filled it all the way up and drove it for 30 min. No problems at all. I will keep yall posted but I think it just had to much air in the engine.
Tech Contributor
Joined: Jan 2007
Posts: 19,362
Likes: 1,128
From: Dyer, IN
Ok problem may be resolved. Yesterday I replaced the thermostat. While I was at autozone the guy there told me to make sure that I "Burp" the car. He said that when you drain the whole system there is air in the engine. I thought I got all the air out after running it for a while. Everything seemed fine. I ran the car yesterday night and it overheated on the highway. I was only 15 min away from my house but took nearly an hour to get home. I would drive it a little and then wait for the car to cool down. I got home and parked it for the night. The next day I woke up and checked the resivior. The resivior was completely empty. I filled it all the way up and drove it for 30 min. No problems at all. I will keep yall posted but I think it just had to much air in the engine.
