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Coolant Air Bubble

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Old Nov 2, 2025 | 05:03 PM
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Default Coolant Air Bubble

I just installed a new Dewitt's radiator in my C5 track car and I think I have an air bubble that I can't seem to get rid of. When I installed the radiator I installed it leaning forward to help with cooling on the track and also vacuum filled the system. I test drove it today for the first time and as soon as I bring it up in RPM's the temp goes from low 180 to 215 and then back down as soon as I go back to cruise. This is a track car and is not run easy so I don't think this going to good on the track. I have tried jacking up the front of the car and turning the heater on full blast but it hasn't helped. Any ideas would be appreciated.

Thanks
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Old Nov 2, 2025 | 06:23 PM
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You can get a coolant vacuum bleeder for less than $100…never have to worry about air bubbles again.



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Old Nov 2, 2025 | 06:30 PM
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As I mentioned in my post, I did vacuum fill the system.
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Old Nov 2, 2025 | 06:51 PM
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Originally Posted by Gcallahan123*
As I mentioned in my post, I did vacuum fill the system.

Sorry but missed that so if you did a vacuum fill it’s not an air bubble in your coolant system…maybe check your cooling fan for proper operation.
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Old Nov 2, 2025 | 07:16 PM
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I had a dickens of a time first fill when I installed a Dewitt’s.
Finally got one of those overflow funnels and let it burp a few times. I also loosen the front steam vents on heads and make sure it bleeds there.
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Old Nov 2, 2025 | 07:39 PM
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Manually "burping" the system should do the trick.
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Old Nov 2, 2025 | 07:57 PM
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When you say manually burp, are you talking about loosening the steam ports on the heads, because I have run the car for a long time with the front on jack stands trying to let it burp. I never had a problem before I, don't know if the radiator leaning forward makes it more difficult or not. Also I'm not sure if putting the vacuum back on it with system full of coolant would help.
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Old Nov 2, 2025 | 08:14 PM
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Originally Posted by Gcallahan123*
When you say manually burp, are you talking about loosening the steam ports on the heads, because I have run the car for a long time with the front on jack stands trying to let it burp. I never had a problem before I, don't know if the radiator leaning forward makes it more difficult or not. Also I'm not sure if putting the vacuum back on it with system full of coolant would help.
Unless you have some sort of modified cooling system with pressure cap on the radiator, raising the front of the car is completely ineffective. The system is designed to be purged of air on a level surface through the coolant reservoir. Raising the front of the car puts the reservoir at a lower point.
It is still not clear to me what the problem is. You have not stated the engine is overheating, and hitting 180 is only possible if you run the crap out fans.
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Old Nov 2, 2025 | 09:51 PM
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Originally Posted by Gcallahan123*
When you say manually burp, are you talking about loosening the steam ports on the heads, because I have run the car for a long time with the front on jack stands trying to let it burp. I never had a problem before I, don't know if the radiator leaning forward makes it more difficult or not. Also I'm not sure if putting the vacuum back on it with system full of coolant would help.
Okay, run the car for three minutes. Shut it off. Carefully open the overflow tank. Squeeze the upper radiator hose and burp the air out. Add more coolant/water and repeat as required.
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Old Nov 2, 2025 | 10:11 PM
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Originally Posted by jcgunn
Okay, run the car for three minutes. Shut it off. Carefully open the overflow tank. Squeeze the upper radiator hose and burp the air out. Add more coolant/water and repeat as required.
you are joking ,right?
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Old Nov 3, 2025 | 10:51 AM
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Originally Posted by lucky131969
you are joking ,right?
Nope, it works like a champ. Just used this procedure on my 03 Vert. The air comes out of the open overflow tank, just add more 50/50 mix to top off as air escapes. Repeat as required.
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Old Nov 3, 2025 | 11:14 AM
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Originally Posted by jcgunn
Nope, it works like a champ. Just used this procedure on my 03 Vert. The air comes out of the open overflow tank, just add more 50/50 mix to top off as air escapes. Repeat as required.
No trying to offend or give you a hard time....but the advice/method just does not make sense.....for any car. Running the engine for 3 minutes is unlikely to open the thermostat unless the engine was just shut off recently, and you need circulation to get the air out of the system. Have you been unsuccessful with following the factory procedure?
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Old Nov 3, 2025 | 06:50 PM
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Got the problem fixed, I tried several things and then I vacuumed the system one more time and topped it off and that seemed to do the trick. Thanks for your input on my issue.
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