auto climate weird knocking noise

[EZStreet]

Today I cranked up the 03 yukon and When the climate control kicks on, I get this weird "klack, klack, klack" noise coming from the dash. It usually just does 3 knocks and stops, but it seems to do it when the compressor kicks in. I almost sounds like something is hitting the underside of the dash....any ideas?

 

[stephendudra]

I hope to see who has these same issues. I do and gave up on trying to find out what it is.

 

[Rivieraracing]

Here's a stab in the dark, maybe something small is on the fan motor blades and makes that noise only when it starts to spin, maybe that is why it only does it for 3 clicks.
Maybe also a sticky blend door, gets hung up when trying to open or close.
Like I said, just stabs in the dark, could be completely off, especially since I can't hear it for myself!! Good luck!!

 

[metro273]

I think it's the mode door actuator/actuators?
These are the little motors that control/move the doors for mixing the cold and hot air.

 

[EZStreet]

I am thinking thats prob what it is. Plan on taking the dash apart tomorrow and checking it out, hopefully its just the little servo or something inexpensive. Air is still blowing ice cold

 

[EZStreet]

So I thought i had it fixes, but now its gotten worse than before. Now every time I start the truck (whether the AC is on or not), I get about 40-45 klacks instead of 3. And the air only blows through the defroster vents now, no upper or lower vents are pushing anything. This thread's been up for awhile, anybody had a similar problem and have an idea what it is/how to fix?

Thanks

 

[05tahoe]

It sounds like the blend door actuator to me. Ive replaced a lot of them on Gm products over the years.

 

[burbanman03]

me too

i bought my 03 a few months back and it has done it since i bought it everything works fine and all but just annoying.

i couldnt figure out how to explain it on here to try and get some answers im glad you did though

come on guys help us out on this one

 

[EZStreet]

It sounds like the blend door actuator to me. Ive replaced a lot of them on Gm products over the years.

Thanks. It sounds like thats what it is. I have been looking for a writeup online all morning but I cant seem to find much. Could you do me a solid and give a quick rundown on how to replace?

 

[667theneighbour]

My climate control doesn't change mode. It blows through the vents into the car only, not to the floor or windscreen. Tried to replace mode acctuator and control panel. No luck yet. Any suggestions?

 

[burbanman03]

.

anyone come up with anything on our problem here?

 

[667theneighbour]

Today I took the car to a garage that found out what's wrong with my CC. I don't know the American name for it but it's a big thing under the dash that leads air to the various nozzels by opening doors on the big thing. Two of the doors are stuck. Estimate price: $1900 + the part if it's broken.

 

[EZStreet]

I'm 99.9% sure its the blend door actuator. I ordered one from Rockauto.com, $135. Make sure you order the one with auto climate control, there's 2 different types and the cheaper one doesn't do the Auto Clim. Screw taking it to the dealer, I'm going to install myself. Apparantly you can get to it fairly easily if you take off the dash, I plan on taking pics of the process and posting them later if I'm not too pressed for time. $1500 to replace a part that costs $135 is absolutely ridiculous, I'm surprised GM has any financial problems at all considering what they charge for service.

 

[667theneighbour]

It's not the actuator. The doors are stuck and the acctuator works fine when removed from the blend door housing.

You don't have to remove the dash to replace the actuator. It's located under the dash in the driverside footwell. I think you must pull off a cover to get to it. It can be replaced with very little effort.

 

[EZStreet]

Was your unit making a series of tapping noises upon startup?

 

[667theneighbour]

Was your unit making a series of tapping noises upon startup?

No it didn't. It worked fine when I parked it and didn't work when I started the car again.

The sound the thread initiator is hearing might be the blend doors tapping if the door sensors are bad. Maybe it's trying to close the doors more than they should and open and close them several times before giving up. Just a thought.

 

[667theneighbour]

Inside the housing the controls on the doors are almost like gears. Maybe the tapping-noise thread-starter is hearing are these gears slipping and the actuator motor keeps turning and slipping the gears for a while before giving up getting proper signals from the door sensors. Another thought.

 

[rudolph]

Did It Work?

I'm 99.9% sure its the blend door actuator. I ordered one from Rockauto.com, $135. Make sure you order the one with auto climate control, there's 2 different types and the cheaper one doesn't do the Auto Clim. Screw taking it to the dealer, I'm going to install myself. Apparantly you can get to it fairly easily if you take off the dash, I plan on taking pics of the process and posting them later if I'm not too pressed for time. $1500 to replace a part that costs $135 is absolutely ridiculous, I'm surprised GM has any financial problems at all considering what they charge for service.

Did you install the blend door actuator purchased from Rockauto.com? If so, did it fix the knocking/tapping noise? I have the same problem with my 2005 Tahoe right now and don't particularly want to pay $1500+ to get it fixed. If you would be so kind, can you walk me through the process of replacing the actuator or getting the doors to no longer stick?

 

[667theneighbour]

Have you tried calibrating the blend-door-actuator? Just disconnect the battery for a while, 15mins I read somewhere. Then re-connect and start the engine. Leave the climate control alone for about a minute while it self-calibrates.

Replacing the actuator is a piece of cake. Just two screws. But before you buy a new one remove it but leave it plugged in and try the various settings to see if it moves. Also try to move the blend doors. You can feel a semi-wheel that the actuator moves. Just try to turn it and see what happens.

Taking apart and putting the dash back together is a good days work, but not difficult. I did it to remove a pen that jammed a blend door. I didn't take out enough to remove the blend-door housing though.

 

[EZStreet]

I did replace it actually, Wasn't too bad. I ended up winning an actuator on ebay, cost me about $95. Part number is 89018365.

http://cgi.ebay.com/ebaymotors/ws/e...22863813&ssPageName=ADME:B:EOIBSA:MOTORS:1123

There was only one on ebay, I searched by part number. Otherwise I was going to buy it from RockAuto, they seem to be legit. All I had to do was take off the knee plate under the driver side dash bezel, you can get to the actuator from there. Its up under the dash on the right hand side towards the center of the vehicle. Make sure you line the teeth up on both pieces or you'll only get lower or upper vents depending on how the door is stuck. You'll see what I mean when you get under there and see the setup.