The Rattle Battle

[BeefyKing]

Hi all. I picked up a 2001 SR5 this past weekend, it has 129k mi., is in incredible condition, and it has an annoying rattle that I need to diagnose. I did see a couple of similar questions from 1-2 years back, none of which indicated any findings.

It is coming from behind the glovebox, is intermittent, comes and goes as it pleases. It sounds like it could be a fan motor, but it is not affected by the a/c controls at all. I thought maybe it was the (broken) antenna motor running, but it is not affected by turning off/on the radio. It sounds exactly the same when idling, or at highway speeds. It may come on at startup, or after 5 minutes of driving, it stays on for a few minutes, and then goes away without notice.

I have only driven short trips over the past 3 days, and have not been able to crack the hood while it was happening yet. Any insight as to what it may be would be greatly appreciated.

Thanks for creating such a great resource here!

 

[jgue467]

Probably not your issue but mine rattled or buzzed at times, found out it was my gf shutting off the passenger vent causing the buzz/rattle...

 

[BeefyKing]

Thanks for chiming in. The rattle is the same regardless of blower or a/c usage.

 

[jgue467]

You already pulled the glovebox back to check for stuff bouncing around in there? Anything loose in the engine compartment/exhaust shields?

 

[Jowenbrown]

I've had this problem with vehicles in the past & it drives me crazy. I had to tear apart a dash once to find it. Problem is that it could be just about anything. Luckily it isn't that hard to tear it apart in a 4Runner, so give yourself an hour to find it. Let us know the results.

 

[BeefyKing]

It doesn't seem to be caused by vibration/movement of the vehicle. More like a fan motor bearing type sound. 2 seconds of rumble, 1 second of no rumble... On and off like that, etc. As soon as the rain stops I will investigate more. It has not done it yet with the hood open. Nothing obvious is loose.

 

[AZ4Running]

You said ac blower motor. Does it still make the sound when you have the ac and blower motor totally off? I have found leafs, coins, plastic spoons and all kinds of stuff inside the ac box where the blower motor is located. If the noise is onky when the ac is on then look to the blower motor. Post back and we can go from there.

 

[BeefyKing]

No. First thing I did was switch the a/c off. The issue is there with blower completely off.

 

[AZ4Running]

Ok time to start looking and listening under the dash.

 

[spmarfatia]

Try putting your vent on to letting the out side air come instead of recirculating and also the other way around. I am talking about the sliding lever just about the A/C on off switch. (this is in my 98 limited)

I think there is a motor behind the glove box that can operate independent of if your AC is on or off.

Mine makes some rattle and noise when mine is set to recirculation. And I heard this is a known problem.

 

[BeefyKing]

Ok, I found the culprit. I thought it was coming from behind the dash, but it is actually this guy...



This is just behind the bottom of the dash, to the left of the passenger's feet.

Is this the motor that switches to recirculated air? The white plastic part on top is jiggling and causing the rattle. Not sure why it would be doing anything with the blower and A/C completely off.

 

[spmarfatia]

I haven't fixed mine yet, mine wasn't that bad and when it bothers me, I just put it out of recirculation. And so far, with the system not set to recirculate, it has never happened to me.

See if you can switch between the settings, and on mine, it only happens when set to recirculate. (or other way around, not 100% sure, mine happens very rarely anyway)

But when mine happened, it seemed from something attached to the outer wall and towards the engine compartment. I actually opened the hood and it felt in the area of the engine compartment behind the glove box. and I could also feel the vibration in the body panels.

Once I moved the setting on the air flow, it went right away. In my case, AC was off and fan was off, but the motor can still recirculate if set to it.