Buffeting sound in 2015 EL

[Barjrob1972]

I just got back into an EL after getting rid of our 2007 several years ago. My wife and I decided it was time because, frankly, we love the things. So, finding a used 2015 EL XLT with 40k miles and AWD/4WD, we jumped on it. I noticed it was missing the front skid plate so this forum pointed me to a source for replacement with an aftermarket parts. Great! Now for the only thing that seems to be wrong with the 2015 EL which the 2007 did not have. Issue: it has a strong wind buffeting noise with the windows rolled up and doors closed. Opening the rear vent windows does help alleviate the pressure. I have new Hankook tires that are balanced well, we've had the vehicle checked out and all seems fine, no damage, so I thought maybe the doors were loose or it had a bad gasket. First, I tightened the doors. The rear hatch seemed to be loose and the rear window did not seem to seal tightly enough. These were snugged up and now it takes some effort to close the rear hatch all the way. It's tight! Probably a little too tight now. All gaskets have been checked - I coated them with Vaseline and closed the doors to be sure they were sealing. All good. Got everything cleaned up and took it for a ride. The buffeting effect was greatly diminished as before it was horrendous over any little mogul or bump in the road, to the point it made my wife nauseous. Now it's at least livable but can be still present. I even tried the AC on fresh/recirculate to see if that made a difference and it's negligible. I'm grasping at straws that maybe not having a front skid plate is somehow directing wind under the EL causing the issue.
Anyone else have this problem?

 

[Flexpedition]

Remove drivers side tail light. Behind it is what looks similar to the dryer vent on the outside of your home. This device is what controls cabin pressure. Make sure the rubber flappers move freely and aren't all gunked up. Directly below it is some mesh. Make sure that mesh isn't full of dirt/mud that would inhibit airflow.

When you switch your air conditioning from fresh outside to recirculating mode, can you hear an audible difference?

This random youtube video shows the tail light removal incase needed:

 

[Barjrob1972]

Excellent! I was wondering where the vent was located. I'll check it out.
I was going to do the soap test but this will be easier and less messy.

 

[powerboatr]

x2 on the vent thingy.
I was going to also add to check the rear door lower rubber, but it sounds like got it covered.
ours is HORRIBLE if you crack a rear window at speed.
might check the sunroof if you have one to make sure its level all the way around, even a 1/8 inch will make funky noises

 

[powerboatr]

and check the rubber grommet from the spare tire access ..40k plus miles i bet the spare has been removed a few times
then run the ac with the recric selected and see if it sofftens the buffetting

 

[Adieu]

Added to my todo list as well

 

[Barjrob1972]

Here's what I did, and hopefully I won't regret it but it's easy enough to fix. I removed both rear lights and checked the rubber flaps. They did not seem to be blocked so I just completely removed the cheap rubber flaps and set them aside and took it for a ride over some rough roads. There was no 'pressure wave' inside the cabin anymore with the windows up but there is still a thumping sound, like someone tapping a hollow bucket and giving the size of the interior, it's a bit "echo-y". Oddly enough, it's worse on smooth roads than rough roads. I checked the spare tire and it's nice and tight. It has never been removed nor the tire tools used. This was a rental vehicle so I'm not surprised about that. I went ahead and lowered the spare a bit then reseated the tire. I'm still awaiting my front skid plate. The sound is definitely coming from the rear and I noticed the water bottle in the holder seems to rattle at the same frequency as the 'drumming' so I'm leaning that it *might* be rear strut related. I'm leaning suspension also due to I carried about 150lbs in the back and I didn't notice the thumping anymore which tells me the slight suspension compression might have something to do with what's going on. I'm probably going to leave the flaps off and just cover the holes with some filter media to keep sand and dirt from getting in. I can't see where water could get in so I'm going to run it like this for awhile and see what happens. I'm also thinking the tail lights seat so well that it *might* be interfering with air movement but at this point it's just conjecture on my part.
Still working on it. If I find a solution I'll post up.
BTW, my tire pressure is at 33lbs cold so they are not over inflated. I've also tried with with tire pressure up to 40lbs and there was no difference.

 

[powerboatr]

oh dude
not sure if this helps
but your description of the echo y type sound from the rear.
i am not sure if yours is the long wheel base, but you said adding weight to the rear took some of the noise out, correct. Was this weight added to the rear cargo are or in the way of a passenger ?
i ask because in my EL the cargo management area plastic covers, fit a bit loose and would vibrate on certain type roads, took weeks to figure it out. At first i thought it was the liftgate latch it was not it.
what i did find was the two plastic lift up covers were not real tight fit in the little latch area or plastic grab that holds it down.
so i took two rear floor mats from my old KR and placed them, one on each side of well.
the fwd plastic thingy resides in that and lifts up to be a shelf or a divider, sorry i have know idea what is called. it solved the plastic on plastic reverb .
surprised the large plastic shelf thingy was so loosely latched.
its hollow.

and in the little area where the jack is, i lined it with some stick on 1/8" pipe foam pipe wrap. so the jack is resting on cushion.

 

[Barjrob1972]

Yeah, the cargo was in the rear with the third row laid flat...on top of the plastic cover/divider. And yes, it's the EL.
I noticed last night the jack did not fit tightly and 'bounced' with hand pressure so I placed my work gloves underneath it before tightening it all back down. You're correct; the jack cover lid does fit loosely. I didn't think about pulling and checking the storage tray.
It got late last night so I'll be spending more time with it this weekend.
NETX huh? I'm from Winnsboro.

 

[powerboatr]

winnsboro ? darn your just a frog hop away from us at quitman