Possible Aux Fan Switch Failure?

[wagner.a.charles]

Also, running the AC at full blast makes no difference.

[LVP]

Originally Posted by wagner.a.charles

Also, running the AC at full blast makes no difference.

Makes no difference as in it does exactly the same thing when you turn on the AC? That seems really loud. Is it really the fan? I know the camera mic probably makes it sound worse.

[wagner.a.charles]

Sorry, I meant that when I turn the AC on, the fan doesn't go haywire. Yeah, it's pretty loud. That's why I wanted to get a video. It's not the typical "warming up" kind of sound. It SEEMS like it's the fan, but it's hard to tell. It only does this in the morning when the engine is cold and when I leave for work, it's dark outside. Honestly though, the fan didn't seem to be spinning out of control or anything. I'm open to other possibilities haha!

[g300d]

It looks like it is going on high speed as it should, but it doesn't sound right I agree.

Mine does that on start up but sounds different, you hear the wind roar more than the fan motor.

Sounds like a worn bearing or something in the rotating assembly.

[upallnight]

Originally Posted by wagner.a.charles

Grabbed a video this morning so y'all could hear it. https://youtu.be/u10F4lYYRSA

The fan that you are video taping is not the Aux fan. That fan is the fan attached to the engine water pump.

The Aux fan is in Front of the radiator. If the noise is coming from the fan that you are taping, could be a bad bearing in one of the idler pulley or a bad tensioner. Worse case scenario is that the bearing in the water pump is shot.

[g300d]

Just saw your post where you said it doesn't sound that way at Max AC.

I think it's the secondary air pump trying to pump against a stuck closed secondary air injection valve.

See that silver mushroom sprouting from the left front of the cylinder head? That's the secondary air injection valve. There is a black hose from there going to the secondary air pump. It activates on cold starts only.

Disconnect the black hose from the valve before the next cold start and see if the sound changes.

Is your CEL lit?

[wagner.a.charles]

Hmm I want to say that I replaced the fan clutch a few months ago when I was replacing the alternator. I don't remember seeing anything funky with the tensioner, but that doesn't mean anything. How would I go about testing those things? Maybe seeing it in the daylight will be a good start ��

[wagner.a.charles]

Originally Posted by g300d

Just saw your post where you said it doesn't sound that way at Max AC.

I think it's the secondary air pump trying to pump against a stuck closed secondary air injection valve.

See that silver mushroom sprouting from the left front of the cylinder head? That's the secondary air injection valve. There is a black hose from there going to the secondary air pump. It activates on cold starts only.

Disconnect the black hose from the valve before the next cold start and see if the sound changes.

Is your CEL lit?

Nope, it's not on. Went off when I replaced the throttle boot

[g300d]

Well, remove the hose to the valve anyway, a failing secondary air pump is also known to get pretty noisy, and those pumps only turn on at cold starts.

I remember that sound from when I had to diagnose my own secondary air injection system...sounds very familiar.

[upallnight]

Originally Posted by wagner.a.charles

Hmm I want to say that I replaced the fan clutch a few months ago when I was replacing the alternator. I don't remember seeing anything funky with the tensioner, but that doesn't mean anything. How would I go about testing those things? Maybe seeing it in the daylight will be a good start ��

Remove the serpentine belt and see if the noise is still there. If it's gone than one of the pulley or bearing that is being driven by the belt is the cause for the noise.