Unbearable humming/buzzing noise from cargo carrier w/factory roof rack

epodietz · Jul 16, 2017

Someone out there must have had this problem, but I haven't been able to find a relevant thread, so I am creating a new one.

Last spring 2016 I bought a used 2014 Outback Premium from a Subaru dealer. It had the factory roof rack. When I mounted & loaded the rooftop carrier I'd reliably used for years on my 2000 and 2003 Outback's w/factory racks, I got a loud unbearable humming noise that started around 50 mph and wouldn't go away at higher speeds. The speed it started at seemed to be wind dependent. No amount of duct tape, jammed in towels, etc would make a difference. And it drowned out the radio. I couldn't figure out exactly which part of the rack or carrier the noise was coming from. It was definitely a vibration (harmonic?), not a rattling, loose strap or that sort of thing. I'd say that it was coming from the whole rack, although it's hard to be sure when listening from inside of the car or through the moon roof. After completing the vacation trip (under 50mph!) I emptied the carrier and found it still made noise at the same speeds. When I removed the carrier and drove with the racks cross wise I did not get any noise.

This year I bought a new Thule carrier which was longer and more streamlined, figuring it was the old carrier that was the problem. Another reason I bought Thule is that it seems that is the model that Subaru endorses. Guess what...it makes the same noise, although it seems to start at a slightly higher speed.

Has anyone out there had a similar experience? And have you found a solution?

Thanks!
Eric in Philadelphia

Superdave54 · Jul 16, 2017

I've used a full-sized Thule pod on my 2014 on several trips and never had such a noise. If I open the sun roof, at 40 plus speeds I get some wind noise, but only a "whooshing" sound. I have driven with the pod full and empty.

My pod came with a heavy rubber sheet that sits on the inside bottom, and I put a piece of carpet on top of it to keep things from shifting around. It also came with some metal plates that go between the bottom of the pod and the top of the rack cross bars to keep the bottom of the pod from distorting when you tighten the clamps.

Any chance the bottom of your pod is flexing/vibrating at speeds causing the humming/buzzing? The bottom of mine is pretty thin and flexible, and I could see it happening without the plates and the rubber sheet.

epodietz · Jul 16, 2017

I guess that's a possibility that the bottom of the pod is flexing. I have a rubber mat so I'll try that just for the heluvit, although I get the same noise with both of my pods, whether loaded or unloaded.

Super Dave: Which position do you have the movable (rear) brace? All the way back or closer to the front brace? Mine is closer to the front brace.

Thanks

rasterman · Jul 16, 2017

Is there a good gasket around the edge of the box opening? It may not be making a tight enough seal. Dynamic air pressure forces the seam to open a little, lets air in. The plastic then rebounds, closes the gap (makes a sound) and then the cycle repeats (very quickly) to result in a loud buzz.

I would try using a ratchet strap or similar device to bind the halves of the carrier more tightly. Start with it close to the front, test drive it, then move it back a foot and try again until you find the spot where the extra clamping force does the trick.

You can also try fairing over the seam with a bit of tape- again just a temporary measure to figure out where the air is getting in. The permanent fix may involve more weatherstripping, adding an extra closure or both.

Another possibility- if the box isn't sitting square and level for some reason, it may be distorted just enough to prevent the existing seal from working properly. You might experiment with that a bit.

epodietz · Jul 16, 2017

Interesting idea, but having used the older carrier for many years without a problem on older outbacks, I doubt that's it. But if nothing else works I might give it a try.

Plus the identical noise is occuring w/two differently shaped carriers...

Red Suburu · Jul 16, 2017

Is there any possibility anything is loose with the mounting of the roof rack itself? Since it didn't do it when on your older car and does it with the old and the new on your new car...I believe that is where I would be looking.

epodietz · Jul 16, 2017

I think that you are onto the right track w/that thought. Unfortunately the mounting assembly is not obvious. The sound seems to be coming from the right side, but there is nothing obviously loose.

I tried placing a hard rubber cushion (actually a small car mat) between the rack and the carrier, but that didn't change anything.

One thing I didn't mention is that opening the moon roof all the way seems to change the air flow enough to make the sound go away. Unfortunately the resulting wind noise is even more deafening. When the roof is open half way the wind sound and buzzing are about equal. Just popping up the moon roof (left switch) doesn't change anything.

Not what I wanted to be doing this Sunday, but a good challenge isn't a bad thing, especially once it's been overcome.

cbst09 · Jul 17, 2017

I had a buzzing from my Yakima, the suggestions in the following thread made it go away.

http://www.subaruoutback.org/forums/104-gen-4-2010-2014/26146-attack-killer-bees-yakima-sky-box.html

georgegiorgio · Jul 17, 2017

Could you share a few picture of the fix?

As I've noticed to have the same trouble recently.

epodietz · Jul 18, 2017

Here's a picture - it's not pretty, but it sure works!

Red Suburu · Jul 18, 2017

Doesn't that mean the front of the roof rack on that side needs to be tightened down????

epodietz · Jul 18, 2017

The problem is that the leading edge of the rubber gasket that is part of roof rack assembly needs some gasket cement. That's what I need to do as a more permanent fix. The rigid part of the roof rack is bolted securely. In case you are wondering, my research of this problem (see youTube under 'removing Subaru Outback roof rack' has indicated that you can only access the roof rack connections from inside of the vehicle, by removing the headliner.

cbst09 · Jul 18, 2017

Glad you got the problem fixed. Perhaps as you said a bit of overkill. a little strip of duck tape on the leading edge did the trick for me. About an inch wide and 3 inches long is all you need. I know, I know. That's what she said

epodietz · Jul 18, 2017

Yes I have some nice black duct tape I considered using, but that stuff leaves a nasty residue. I was hoping to do it right (eventually) and use gasket cement, which is why I used easier to remove plastic tape. Thanks for the tips.

Richard Pare · Jul 18, 2017

epodietz said:
Instant fix! I'll need to get some gasket cement to fix it for real. Or silicone. I don't know which would be better in case anyone cares to comment.

A contact cement would be better in the long-term than a silicone. The best out there is Barge - it is what Fisher Body has used for decades to glue their interior panels together. HOWEVER, there has bee a reformulaton that got rid of the tolulene, and it is nowhere near as strong. the good stuff comes in orange and yellow containers, the not-so-good in blue and black containers. Unfortunately, while the good stuff is still available, it is harder to find it in small tubes now, and is getting expensive.

Next to Barge, DAP Weldwood is excellent.

epodietz · Jul 18, 2017

Thanks for the tips. I have some Shoo-Goo, I wonder if that would work.

reinvintage · Sep 13, 2018

Hi OP, I've read through this thread, as I have the same issue with my 2013 Outback when we put the cargo pod on. Crazy noise that does not let up above a certain speed. What I'm wondering though is why putting tape on the roof rack assembly fixes the problem. Is it that the wind shear from the pod is actually pulling that part of the assembly up enough to catch air? Assuming this didn't occur without the pod attached, which is my case. No noise unless it's attached. Thanks!

KansasMatthew · Sep 13, 2018

There have been other threads over the years about this buzzing.

Some of it has been tracked down to the open holes that are created when you swing the roof rails to their cross-beam position. When you do this, you uncover some holes in the top of the rack. Wind gets inside and creates a buzz, possibly because of air pressure pushing through and out the gasket that the OP sealed with tape.

Their fix was to plug those holes with either tape or foam jammed inside.

stocker · Sep 13, 2018

I was on a 12,000 mile road trip when this problem started. It took a couple weeks to figure out what was going on but we eventually resolved with the same method above. I used black gorilla tape which doesn't typically leave the weird residue of duct tape.

I was so excited to solve this thread but we all stumbled into the same solution!

Anything on the roof changes how the air flows. In this case, I think the pod tends to push the air more down ward into the roof and cause the thin gasket to act like a reed from a wind instrument. Like a kazoo!

Cmberube · Nov 17, 2018

Drove 1600 miles listening to what sounded like a thule box full of angry bees. Read threads indicating its the rubber gasket under the rail flapping against roof. Can also get excessively worse in hot temperatures...rubber expands & contracts. Will be using cement or silicone next summer trip.

Unbearable humming/buzzing noise from cargo carrier w/factory roof rack

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