Recently my heater stopped working. Around the same time I noticed a sound that sounded, honestly, like something rustling in the dash behind my glove box.

i thought I had a rat, as I park my truck outside and it’s been cold. I took the glovebox out and saw no sign. There was no disturbed dust and cob webs back there.

I’ve researched this could indicate a problem in the heater core, maybe “bubbles” or air pockets in the coolant.

thoughts? What are my next steps to repairing. Thank you!

 

What year truck? From your description i would check out the blend door.

http://www.heatertreater.net/?gclid=...SAAEgIQmPD_BwE

 

99 Ram 1500 4x4. I can’t make the noise happen, it just does at random. It’s more prone to happen on acceleration.

 

Check your coolant level. If it's a gurgling sound like a rat gargling, you may have air in the core. That would stop heat as well as make noise. Make sure your overflow reservoir is where it should be for hot and park the truck on a flat or slightly raised front area. Use SEVERAL paper towels and loosen your radiator cap to the first of two notches. You will either get coolant or air blowing out around the cap. (That's why you use many sheets of towel) If you're blowing air out, top it off and and drive the truck. When it does it again, repeat. Eventually, you'll get all the air out and it should go away and give you heat.

 

Thanks! I tried that and something unexpected happened. I found I was low on coolant so I topped it off and did as you said. A lot of air escaped. Now the truck indicates overheating just driving around the block! It’s never done that before.

 

There's an air pocket under the thermostat. It should blow thru once it opens. Make sure your radiator is indeed full. Let it sit an idle, and watch the coolant level. (radiator cap off.)

 

Would it be worth just doing a radiator flush and starting new? I bought the truck used last year and who knows when it was done last.

 

Probably wouldn't hurt.

 

Never done it before. I found this link..

https://dodgeforum.com/how-tos/a/dod...adiator-394095

Are there any additional steps the author left out or would you add any more? I’ve always been scared to touch my radiators because I’ve had such bad luck with them! But it’s time to learn.

 

I like to make sure the thermostat cycles several times while burping the air out of the system. Also, with our trucks, in order to get most of the air out, need to have the nose of the truck as high as you can get it. I parked on a hill....... a steep one...... still couldn't get all the air out of the heater core...... It's a fun job.