Climate Control Fan Noise

[safesaxbdd]

Has anyone experienced a high-pitched whining when the climate control fan speed is adjusted? I feel like it's gotten worse, I used to be able to manually adjust speed up or down a notch and it would go away, but now most of the speed range it whines. Anyone know if this is the blower motor assembly? I'd like to know what to focus on to fix

I should mention the evaporator foam is also coming out, not sure if the two are related...

[Stl-986]

well if the noise changes when the speed of the fan changes, that really points to the fan right?

[A8ked]

I noticed my fan made an annoying sound that I could hear at the lower fan speeds. So I bought a used fan from a recycler and swapped them....still have the noise! I had already replaced the foam on the HVAC doors first thinking the sound may have been related to them.

Replacing the fan assembly was simple and cheap, IIRC the used fan was $35. I'm just living with the sound for now or running the fan at the higher speeds. If I wire the original fan up and run it on my bench I can hear any odd sounds, so maybe there's something else in the system that I've missed.

[safesaxbdd]

Originally Posted by Stl-986

well if the noise changes when the speed of the fan changes, that really points to the fan right?

Thanks Stl-986, & A8ked. I would think it was the fan but you never know with these cars - just wondering if this issue is common and folks have encountered it before

[KevinH1990]

Sorry to dredge up an old thread, but I think my fan is starting to be troublesome. Here are my facts and symptoms:

2000 Boxster with 151,000 miles. I usually drive the car 3-5 times a week, but it has been almost a daily driver this summer. I removed the foam from the blower control doors about 3 years ago.

The first time I started the car after I returned from a 10-day trip I heard a brief high-pitched whine. Now, I hear it every time I start the car in the morning. It continues for 30 seconds to two minutes and then stops. I don't hear it when I restart the car for subsequent trips or in the afternoon when I have driven the car in the morning.

When I drove the car two days ago, I shut off the HVAC fan at a stop light and the noise stopped. However, the engine had reached operating temperature at that point, and it that could have been why the noise ceased. I'm having difficulty pinpointing the direction from which the noise is coming. I'm planning to turn off the fan the next time I start the car and see what happens.

If it does turn out that the HVAC fan is the source, it sounds like a used part might be the most economical option. I was wondering whether other automakers use the same part and if the HVAC blowers from Audi or VW might be an option.

I found a DIY video and the procedure looks similar to the one I followed when I replaced the HVAC fan in my 2005 Mercedes C230.

Please let me know if you have suggestion or a used fan sitting around.

[KevinH1990]

I had time for more detailed investigation yesterday.

The noise cessation when I turned off the climate control fan earlier in the week must have been a coincidence. When I turned off the fan yesterday at the start of my drive, it had no effect on the noise. On careful inspection, the noise seems to vary with engine speed for the first 9-10 minutes of the initial drive of the day. Then it stops and doesn't reappear during later drives on the same day. I'm beginning to research other potential causes. One area I'm exploring involves the secondary air injection system.