Vibration in dash when heater is on.

Blown 346 · 12-04-2009, 02:54 AM

I have a 99 alero, I have to replace the blower motor resistor as the first 3 settings dont let the fan kick on.

Anyway, the last few settings always worked fine until tonight. I started the car with the fan on setting 4 to warm up and thaw out the windshield.
I get in the car and the center console is vibrating like crazy. I turn the fan up one notch and the vibration just gets louder, I go to the last setting and it is horrible.

I would like to know what is causing this... I dont want to fan to take a dump on me in the cold while Im driving.

Any help would be great.

El Pablo · 12-04-2009, 08:09 AM

I wish I could be of some help on this. I have this problem too sadly.

lonnie · 12-04-2009, 08:09 AM

Well sounds like if the vibration gets louder with the blower motor then that may be whats going up, or is loose some way.

Nate's Alero · 12-04-2009, 08:19 AM

something's gone in the blower motor, maybe the cage is fried, or broken

Redog · 12-04-2009, 05:05 PM

Is it cold where you are? Has the car be sitting for a while in the cold weather?

My car did this when I got back from England. The car sat for 2 weeks and it was in the high 20's low 30's It went away after about 2 days

AndyT3 · 12-04-2009, 05:15 PM

Could that have something to do with some water getting in under the cowl and through the air intake and getting in the blower motor cage and then freezing due to the temp and then making some noise when turned on? Just a thought...

Redog · 12-04-2009, 06:07 PM

^^ possible, it did rain a lot those 2 weeks

TheEdgeofSanity · 12-04-2009, 10:16 PM

I had that happen. Most likely your blower is full of ice. I had the same thing happen and I can't fix the leaking.

AndyT3 · 12-04-2009, 11:11 PM

Did you try the foam sealing strip under the cowl?

Blown 346 · 12-04-2009, 11:27 PM

The car has been sitting for a few weeks, maybe driving it once every few days. It did get cold here, its been in the 20's and low 30's the last few days. We had some rain and then it froze and then it snowed. I only noticed the vibration after it snowed.

Having the cage or blower motor freeze seems like the issue. Foam sealing strip? No I havent tried that.

AndyT3 · 12-05-2009, 02:08 PM

GM has a bulletin out (#01-08-57-003) that talks about the water getting under the cowl. Within that bulletin is a part number for the sealing strip (GM part number #22680817) that my Chevy dealer special ordered for me for $6.27. Maybe take a look into that if it keeps getting water in there. It must not be a lot though if you don't notice water on the pass side floor, because with mine, it was a steady leak down to the pass floor.

Blown 346 · 12-05-2009, 03:07 PM

I have no water on the floor. I drove the car today with the same noise, parked it at home once I was done running errands. Then left again about an hour later and the noise stopped and is no longer there.

Im going to replace the motor resistor and Ill check out the cage when im in there.