Jack SuperDork
Sept. 16, 2009 11:33 p.m.

2006 Malibu LT 84k miles.

Just yesterday, the heater stopped providing heat. When the car is up to temperature, the radiator and heater hoses are hot, the temperature gage goes to it’s normal position, but no matter where the temp selector is set, the vents only blow cold.

If the car is parked, when already warm, the first few minutes of running will yield heat, but then it goes cold. I suspect this bit of heat is from the heater core and is seeping around the damper that controls whether the air flows across the heater core or not. I suspect it’s the damper, as there is no sound like a moving damper when moving the hot/cold knob, although I'm not sure it made noise before. Changing from vent to floor to defrost makes a whirring sound.

I’ve pulled most of the plastic pieces from around the heater area around the hump, but stopped short of pulling the actual dash apart, as I’m not sure where the motorized damper is located.

Can anyone provide any guidance as to where this motorized damper is located, how to determine if this is the issue, or am I barking up the wrong tree. Any help (especially a PDF copy of the shop service manual or th appropriate pages) would be appreciated. Unfortunately, I have not found a Clymer or Chiltons for this new a vehicle, only up through 2003, which was the last year before the model change and the Chevy OEM shop manuals are brutally expensive.

Thanks in advance,

Jack

Jack SuperDork
Sept. 21, 2009 10:22 a.m.

BUMP

OK, so I've located two acutators, but neither looks like what I've found images of on the web. Guess I'll be off to a Chevy dealer to see what I can see today. It would be really nice if the actuator can be changed without yanking out the entire dash. I have the bottom half and the center of the dash out currently.

Any help from GRM out there?

Jack . . . . . and yes, I deactivated the airbags. They are serious looking devices BTW.

John Brown SuperDork
Sept. 21, 2009 1:13 p.m.

Go back one step...

Disconnect the heater core and back flush the heater core to make sure it is not full of DEXCOOL sludge.

Jack SuperDork
Sept. 21, 2009 2:02 p.m.

John,

Great suggestion!!! I had checked the hoses into and out of the core to verify they were hot.

As I approach 88k miles I have been trying to figure out if I should flush all the Dexcool out, i.e., fill with water several times, driving the car for a day or so in between, then fill with REAL coolant, or just refill with the Dexcool. I'll have to do some searching on this one.

Back to the issue. I went to the Chevy Dealer to get some drawings, which they had. The service dept suggested pulling the codes (Duh, why didn't I think of that?), as well as checking for heat in the hoses. The parts guy supplied drawings adn let me know it's a $50 part. As I got back into the car, I made some threats (to the car) about having the drawings now, the I could dig in with fervor. I reached down to where that actuator was, and turned the heater knob to see if I could feel it vibrating as it moved, and oddly enough I could. I though this was odd, but figured I'd check it out tonight at hom. When I started driving away, the heat was back. Yesterday, I took the control unit apart. This is the control assembly with the knobs. I worked on it and all sorts of electrical connections, but I didn't try hitting the heat again after reassembly, as the control unit tested out OK, as far as my Fluke DVM could see.

The Downside:This could go bad again at any time, so I'm not going to put it all back together again real quickly.

The Upside: This actuator is replaceable without ripping the dash completely off. Pulling the drivers side knee bolster off affords extremely marginal, but likely acceptable access; I think the actuator can be replaced in situ.

Thanks for chiming in John!

Later,

Jack

AdamDecker
AdamDecker New Reader
Nov. 12, 2009 2:34 a.m.

Under Floor Heating mats are DIY friendly or can be installed by a handyman or contractor. All wiring should be done by an electric professional.

BoxheadTim Reader
Nov. 12, 2009 3:56 a.m.

Do those heating mats work in canoes as well?

You'll need to log in to post.

Also on Grassroots Motorsports

We're Back In Monterey for Car Week

23 hours ago in News

And so it begins, another trip to Monterey Car Week.

Deal of the Month: Free Trackside Companion!

1 day ago in News

Ever wished you had a handy guide on how to dial in your alignment or adjust your dampers?

This Tuesday: Join Us at Track Night in America

1 day ago in News

This Tuesday we'll be running at Palm Beach International Raceway

Experience Monterey With Us

1 day ago in News

We're on our way out to Monterey, California, for car week.

Concours d’Lemons to Ruin Monterey Car Week Yet Again

2 days ago in News

What started as the anti-concours has transformed into a major event on the Monterey Car Week schedule.

Tomorrow, August 15: Join our Monterey Kickoff Cruise-In

2 days ago in News

Our Monterey welcome party is taking over all of downtown Pacific Grove.

Vintage Views: Classic Mini

4 days ago in Articles

Turn heads, have jolly good fun.

You Need This: Toyota With Rally Pedigree

4 days ago in News

Who can say no to a turbocharger and all-wheel drive?

Join Our Monterey Kickoff Cruise-In at Pacific Grove on Tuesday, August 15

5 days ago in News

Our Monterey welcome party is taking over all of downtown Pacific Grove.

You Need This: J. Geils's Maserati Sebring, Some Assembly Required

5 days ago in News

A rock star project will be auctioned off in Monterey next week.

Who Wants a Skip Barber Car?

5 days ago in News

Skip Barber Racing School is selling off Miatas, Mustangs, Porsches and much more.

2018 Mercedes-Benz E400 4Matic Coupe

5 days ago in New Car Reviews

A Mercedes-Benz is an animal with few equals. I don’t mean that no one else makes a car that’s as ...

OUR SPONSORS

Grassroots Motorsports Magazine

Subscribe Today

Also get your instant access to the digital edition of Grassroots Motorsports Magazine!

Learn More
8I5P9MNB2EguwF8ffuRfvI96KsJoZVQg