Vibration/knocking noise under passenger seat

[honhon]

Hey all… an issue is randomly showing up in my wife’s explorer…
When slowing or coming to a stop it seems like there is something rattling or vibrating under the front passenger seat floor.

and to be specific where the noise is… it’s directly under the front passenger seat so the middle row passenger side person can feel it but not the front passenger seat person.

I haven’t felt it but a back seat passenger said they felt it with their feet…

it’s intermittent and not consistent.. I thought at first it may be the flex pipe TSB but it goes away… and I hit the flex pipes and there’s no noise…

honestly it sounds exactly like an ABS pump doing it’s thing to not lock up the brakes… but when it happens it’s not an emergency braking situation… it’s just a slow and controlled stop or slow down…

I haven’t taken the under body panel yet to see what’s there but I was curious if anyone else has come across this…

thank you

 

[Chamorro85]

I've been actively ignoring this sound from under my vehicle as well. At least I think it's the same sound. It comes and goes, usually when i'm coming to a normal stop like you mentioned. Sometimes I'm at a complete stop and it will clunk. Thought someone hit me and had to look around and confirm.

Seen others mention stuff like this or similar. Mention each time I go to dealer hoping it will jump out at them. Of course my drive to dealer and back are silent...

 

[honhon]

Yeah I need to pull off that underbody panel and see what’s mounted under there… it sounds just like an ABS pump which is weird… I don’t trust dealers unless I absolutely have to and I want to know what’s going on before I even have the remote idea what’s going on….

 

[Chamorro85]

It drives me crazy that its so intermittent and impossible to describe the sound...but damn is it loud when I hear it.

 

[honhon]

Ok… so possibly a fix today…

I looked in the panel from the right rear wheel area bc there’s an opening back there…

All that runs along the passenger side floor are the fuel and vent lines…

I pulled out some of the clips and there is a 10mm nut just in front of the rear tire… so I could pull the panel down slightly

the fuel and vent lines are held to the body with rubber mounts… the middle mount right by the B pillar felt and looked like it wasn’t snapped completely around the lines…

I moved it back and forth a little and it felt like it snapped in a little better…

I also bent the main vent line slightly to put a little pressure on the mount to keep it in place and I also put a zip tie around the rubber to keep it secured around the fuel vent lines…

with the noise I was hearing and what the passenger was feeling on the floor I could easily see the rubber mount and lines vibrating and making the noise…

 

[Chamorro85]

Interesting...keep us posted on sounds continuing.

 

[honhon]

Well my wife said it was still there and possibly even worse… but I guess that’s good in a way bc if it’s worse then that means I did something to that mount… so I guess I just need to figure out what it’s actually doing

 

[honhon]

Well my wife is saying that it happens all the time now… so atleast I identified where the noise is coming from lol
I’ll have to take the panel down again and see what else I can do

 

[Chamorro85]

Hopefully you were able to isolate it! Good luck.

 

[honhon]

Ok update… I drove the car the other night and I experienced the sound to the full extent with it even happening under normal driving conditions…
I took the car to the store and it did it the whole way there…
We stayed at the store for around 20 minutes or so…. Drove home and it didn’t make the noise at all…
So now I’m thinking the car was fully warmed up prior, but some how it was still doing it…
But with the car sitting there it allowed to have whatever was making the noise absorb some heat and then not make the noise… also when it was making the noise right at the end of the noise it would make a slight squeak noise…
I recognized this noise as the aluminum that they use for the heat shields… I’ve dealt with that same squeak with the same type of aluminum previously at my previous job years ago…

So I can now confirm it was not the fuel lines…

so fast forward a few flu days….

I put the car on ramps and I confirmed the exhaust was tight and the flex pipes weren’t touching or making the sound….

then I started looking around… and I remember the sound coming more from the center of the car and a little more forward than originally thought….

while poking around I found a portion of the heat shield pressed against the transmission crossmember….
It showed witness marks that it had been moving/vibrating….
I pulled it down slightly and let go and it sprung back against the transmission crossmember… it was definitely making metal on metal contact…
So I pulled a little harder to create a little bit of a gap between the heat shield and the crossmember…
I test drove it around the neighborhood and didn’t hear the noise… the noise comes and goes so I cannot confirm it 100% yet but it does amount to the approximate area of the noise… there was witness marks of it vibrating, it was metal in metal contact with the distinct sound of the heat shield type aluminum…and the biggest clue that makes me confident is when I last drove it…
With driving it the heat will be pulled away from the the underside of the car… but when it sat at the store for 20 mins the exhaust heat would rise and heat up the shield which would give it just enough expansion to not make the noise…
I’ll try and report back but if I don’t reply I’d assume that I was successful so far…

 

[honhon]

Well sadly the sound is still there.

my wife sent me a video. It happening just with normal driving too. It really sounds like something is just loose.

here’s a video:

https://youtube.com/shorts/ml9xzDtnTzY?feature=share

 

[Big Dummy]

I listened to the noise your wife’s ride is making and while it doesn’t sound like what I am currently l, the fact the noise presented it’s self while decelerating and or normal braking. I noticed a Banging/clunky noise starting about 2 weeks ago while decelerating and applying the brakes, my wife noticed it also but it was very inconsistent and lasted only about 5 seconds. Well this past Monday it presented itself again and lasted about 10 seconds. I dropped it at the dealer… 2020 ST with 57000 miles. I got it back yesterday evening with a diagnosis of the Front Differential or Axle Carrier is failing. They took the vehicle on several test drives and could only duplicate the noise twice so they put it on a front end lift and while lifted up with the suspension loaded vehicle in drive about 25 mph they clearly saw and heard the front diff making the sound and could feel it while placing a hand on the diff cover. They have ordered a new diff and will be delivered next week and is obviously covered under powertrain warranty. I don’t know if this is your issue but could be worth having it checked out. Apparently it’s not a common failure at this low of mileage but strange things happen. Hope this helps your situation. Shalom

 

[honhon]

The thing with the noise in my car is that it mostly happens under braking but as of late it’s under acceleration as well.

but then if we go to the store and let it sit and then drive it again it won’t happen.

the back seat passenger on the passenger side said they can feel it with their feet also…

Also with the squeak sound near the end that sounds like something is loose.

with the feet feel and the location of the sound it sounds like it’s directly under the passenger front seat…

Im almost starting to wonder if the passenger seat needs to be removed and there’s something vibrating on the floor under the carpet.

 

[Big Dummy]

The noise on mine is under acceleration and decelerating now… I forgot to mention that, it did it under acceleration last Monday and that’s why I decided to drop off that day just to get it checked. You issue could be something else, Hopefully, although I thought the noise it was making was coming from the driveline towards the back. Sound and vibration can manifest in the back and the cause is in the front… at least that’s my current situation.

 

[Big Dummy]

One thing you can try… if you know any mechanics or techs. You can use “chassis ears” to help pinpoint the noise while driving.

 

[honhon]

Well… another try at a fix and I think I may have gotten it… the issue came up around when I installed the MBRP exhaust on the car but I didn’t want to think it was related…

so after my wife got back from making a run to the store… the video I posted was over her trip today…

I put it on the rhino ramps and started poking around underneath…

I looked at the first exhaust support to make sure it was tight bc I loosened it to install the exhaust and it was still tight…

but when I installed the exhaust I noticed the hanger was a little close to the mount but I didn’t think anything of it… but upon closer inspection today I think this may be my noise…

I think it was the hanger from the MBRP rubbing on the factory mount… I loosened the exhaust clamps and adjusted the exhaust to give it a little more room… there are even witness marks on the hanger to indicate they were touching at points…

the first 2 pictures show how close the mount was and then the 3rd picture is of how much of a gap I was able to make…

you can see witness marks on the hanger too

the tell tale sign of this is that squeak in the video… that squeak sounds exactly like aluminum and the factory mount is aluminum so this may be the my issue… it would probably still be a good place to check even on a stock exhaust explorer…

 

[Big Dummy]

Looks like you got it, I hope that’s all it was. These vehicles do have some “Normal” strange noises and when you encounter a noise that’s not normal, it’s a good feeling when it turns out to be an easy fix. Good find man!

 

[Peterfor]

Well… another try at a fix and I think I may have gotten it… the issue came up around when I installed the MBRP exhaust on the car but I didn’t want to think it was related…

so after my wife got back from making a run to the store… the video I posted was over her trip today…

I put it on the rhino ramps and started poking around underneath…

I looked at the first exhaust support to make sure it was tight bc I loosened it to install the exhaust and it was still tight…

but when I installed the exhaust I noticed the hanger was a little close to the mount but I didn’t think anything of it… but upon closer inspection today I think this may be my noise…

I think it was the hanger from the MBRP rubbing on the factory mount… I loosened the exhaust clamps and adjusted the exhaust to give it a little more room… there are even witness marks on the hanger to indicate they were touching at points… View attachment 16080 View attachment 16081 View attachment 16082

the first 2 pictures show how close the mount was and then the 3rd picture is of how much of a gap I was able to make…

you can see witness marks on the hanger too

the tell tale sign of this is that squeak in the video… that squeak sounds exactly like aluminum and the factory mount is aluminum so this may be the my issue… it would probably still be a good place to check even on a stock exhaust explorer…

In the instructions to install the BORLA S-Type they make a note that you should switch the RR and LR mounting brackets. This may fix your issue as well since they will be reversed. Borla even put it in red most likely from receiving phone calls on installation issues as no body reads anymore, easier just to look at pictures.

 

[honhon]

It’s been a few days and we haven’t had the sound… so I’m gonna say it was the hanger

 

[Chamorro85]

It’s been a few days and we haven’t had the sound… so I’m gonna say it was the hanger

Glad you figured it out. I'm bummed now cause I haven't changed the exhaust.