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Old 11-23-2008, 11:01 AM   #1
JJanzen
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Heater Box Noise

When my thermostat opens after my truck warms up, you can hear the water circulating through the heater box. For about 30 seconds, it is very noisy like two squirrels scrambling to get out! Can anyone lend some insight to what is happening and how to fix? Thanks.

Joel
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Old 11-23-2008, 11:57 AM   #2
Bus Ted Knuckle
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Re: Heater Box Noise

you might need a little more water in your radiator. Have you chacked the level after the themostat opens?
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Old 11-23-2008, 12:56 PM   #3
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Re: Heater Box Noise

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Originally Posted by Bus Ted Knuckle View Post
you might need a little more water in your radiator. Have you chacked the level after the themostat opens?
What Bus Ted Knuckle is saying is you may be low on coolant. To get the right amount of coolant in the system you need to "burp" the system.

With the engine cold, take the cap off the radiator, put a catch pan under the open end of the radiator and start the truck. Let the engine warm up. Once you see a good, continuous flow coming through the radiator, fill it up to the top and replace the cap.

I suspect the noise you are hearing is a slug of air that is trapped in the system. Burping it should make the noise go away.
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Old 11-23-2008, 01:20 PM   #4
Richard8971
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Re: Heater Box Noise

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it is very noisy like two squirrels scrambling to get out!

Joel
Have you checked the box for squirrels???

Don
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Old 11-23-2008, 01:23 PM   #5
68gmsee
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Re: Heater Box Noise

Quote:
Originally Posted by JJanzen View Post
When my thermostat opens after my truck warms up, you can hear the water circulating through the heater box. For about 30 seconds, it is very noisy like two squirrels scrambling to get out! Can anyone lend some insight to what is happening and how to fix? Thanks.

Joel
The way you describe it, sounds like a little more than water or air circulating in the system. I've heard the noise squirrels make when they're in a cage or trap.. Loud!

Is this with the fan off and only after it warms up?

Also, does it make the noise without opening up the heater/fan control lever?

Could be a loose squirrel cage, motor, heat control valve, restriction in the heater or the mounting is loose.
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Old 11-23-2008, 01:27 PM   #6
JJanzen
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Re: Heater Box Noise

Thanks everyone for the immediate comments. It sounds a lot like a trapped air bubble. I am going to try and "burp" the system and see if that gets rid of it. I will let you know how it goes. Thanks again for the help.
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Old 11-24-2008, 08:17 PM   #7
JJanzen
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Re: Heater Box Noise

Thank you all for advise. A little additional water did the trick and the "squirrels" are now gone!
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Old 11-24-2008, 08:36 PM   #8
Bus Ted Knuckle
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Re: Heater Box Noise

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Thank you all for advise. A little additional water did the trick and the "squirrels" are now gone!
you have enough antifreeze in the mix to do the trick don't you?
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