air bubbles in heater core
Thread Starter
Cruising
Joined: Feb 2011
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air bubbles in heater core
I guess im sold that my 2001 vert has air bubbles trapped in heater core from this bubbling noise coming from drivers side dash. Does anybody have a solution to get rid of these bubbles because the noise is driving me crazy or will they work themselves out eventually. I tried burping the system as per the service manual but no luck. And why does the noise totally disappear sometimes. If there is air trapped in there wouldnt it make that bubbling noise all the time?
Tech Contributor
Joined: Dec 1999
Posts: 32,910
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
I find it difficult to believe that there is air trapped in the heater coolant system.
If you turn the HVAC FAN off does the noise go away?
I find it more plausible that you are hearing the fan touch condensation that is trapped in the air box.
If thats what it is, you have a drain that is clogged up on the fire wall. Run the system with the HVAC fan OFF and see if the noise goes away.
If you do fine that you have condensate built up, make sure that you do not have wet passengers side carpets and a wet BCM
BC
If you turn the HVAC FAN off does the noise go away?
I find it more plausible that you are hearing the fan touch condensation that is trapped in the air box.
If thats what it is, you have a drain that is clogged up on the fire wall. Run the system with the HVAC fan OFF and see if the noise goes away.
If you do fine that you have condensate built up, make sure that you do not have wet passengers side carpets and a wet BCM
BC
Thread Starter
Cruising
Joined: Feb 2011
Posts: 12
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I hear the noise everytime on start up without putting the a/c or heat on. It appears the same whether i use heat and air or not. As far as the clogged drains i did just clear out the 3 that are together on drivers side firewall. The noise is coming from what i can hear right behind speedodometer in dash. Very weird. It comes and goes but always there on start up.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Ok,, lets go on this theory.. If there is any air in the system, it would have to be caused by:
1, No pressure in the system allowing steam to collect in the lines
2. Head gasket leak.
3. Low coolant level in the reservoir tank
Make sure that the tank is properly filled, make sure that the system is properly pressurized. Theres a newer style cap with a higher pressure rating. Recommending upgrading.
Check the antifreeze for exhaust gasses. Auto parts sell the test kits.
1, No pressure in the system allowing steam to collect in the lines
2. Head gasket leak.
3. Low coolant level in the reservoir tank
Make sure that the tank is properly filled, make sure that the system is properly pressurized. Theres a newer style cap with a higher pressure rating. Recommending upgrading.
Check the antifreeze for exhaust gasses. Auto parts sell the test kits.
Thread Starter
Cruising
Joined: Feb 2011
Posts: 12
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I think I'm good with everything you mentioned. Just recently had a new water pump put in and I've already upgraded the coolant cap. What are signs of head gasket going? And do any coolant hoses route by speedometer? I thought the heater core hoses were mostly located on passenger side.
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Thread Starter
Cruising
Joined: Feb 2011
Posts: 12
Likes: 0
And i think you were right on a possible HVAC condensation problem. If they is air trapped somewhere in coolant system wouldnt the car run hot? My temps are pretty much right on approx 195 degrees when driving
Team Owner
Joined: May 2001
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From: Dear Karma, I have a list of people you missed.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
Have an HVAC tech check your system pressures, etc.
Team Owner
Joined: May 2001
Posts: 36,836
Likes: 244
From: Dear Karma, I have a list of people you missed.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
I remember seeing it when I visited the Corvette Museum in '99. You can tell it's a '97 (or '98) in that pic by the two fuel lines. I would think '97. GM did a nice job. 
Tech Contributor
Joined: Dec 1999
Posts: 32,910
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
There are several rolling display chassis. The one pictured earlier was at Carlisle PA.
Here is the one at Bowling Green
Here is the one at Bowling Green
Last edited by Bill Curlee; Sep 1, 2013 at 09:20 PM.