- Thread starter
- #41
WHOA! Just checked under my inner hood lining, and sure enough, delaminated from the support ribbing!! Going to pull the headliner tomorrow for sure.
What did you use to reglue?
Painful low frequency drone/pressure in cabin
- Thread starter LJE
- Start date
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What did you use to reglue?
If you remove the hood liner you'll be able to see if the factory adhesive has hardened and failed. If the hood is gone, chances are the roof is as well.
The roof and hood sheet metal will sound solid like the door and quarter panels IF they are still adhered to the support structure.
My paint guy used this on the hood and then I did the roof with the same stuff. He likes it because it stays pliable and won't contract and deform the sheet metal like some adhesives.
2 Tube of DOW U-428 Plus Auto Glass Windshield Urethane Primerless Adhesive Glue https://a.co/d/4fwi3FT
Oh and make sure you warm the adhesive up on a jug of hot water etc first. Even using a powerful caulk gun it's one heck of an arm workout.
The roof and hood sheet metal will sound solid like the door and quarter panels IF they are still adhered to the support structure.
My paint guy used this on the hood and then I did the roof with the same stuff. He likes it because it stays pliable and won't contract and deform the sheet metal like some adhesives.
2 Tube of DOW U-428 Plus Auto Glass Windshield Urethane Primerless Adhesive Glue https://a.co/d/4fwi3FT
Oh and make sure you warm the adhesive up on a jug of hot water etc first. Even using a powerful caulk gun it's one heck of an arm workout.
- Thread starter
- #43
Awesome! How many tubes did it take to do the roof? I'll order some now.
Did you clean any of the old stuff off? Or just flex the roof slightly and apply in the gap?
Incredible. Really curious what the root cause will be!
And much more important:
Thank YOU for taking us on a tour of every single detail you try/ test/ do. No idea stays uncommented!
Really great!
And much more important:
Thank YOU for taking us on a tour of every single detail you try/ test/ do. No idea stays uncommented!
Really great!
- Thread starter
- #47
Hahaha, that could be fun! I would think st the very least that it should shift the frequency, since you'd be adding mass to whats effectively a mass-spring-damper system. I'm not sure how heavy of a magnet it would take to make a noticeable impact though.
This forum has helped me learn so much - so I always try to add back in where I can! Also, having helped people remotely with complex problems before, I know how important it can be to communicate details. After all - the only difference between messing around and doing actual science is writing it down, right? Haha.
Awesome - just what I was looking for! Was yours an LC or LX? I've heard that LXs have more damping from the factory, but i'll probably go ahead and order more while I'm at it...
EDIT: Oops, just noticed in your signature you call out LC. It'll be interesting to compare!
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LC here. You'll probably find more insulation/jute up there since it's an LX. I ripped the factory jute out, cleaned up the old adhesive with rubbing alcohol. Then rolled on some deadener and spray adhesived insulating material over that.
Roof just makes a solid thud if you rap your knuckles on it now.
Okay, we can't just let this thread die without closure.
I was thinking tires but that wasn't it. I came here tonight to suggest throwing it in neutral when it happens and see that has been tried and that worked, Right?
Has to be under load?
So now I'm going with an exhaust drone. Not a leak or rattle , but actual resonance in the combo of the headers, mufflers resonator. I've had plenty of horrible resonance when trying to make my various Corolla Hot Rods sound cool and go fast as a crazy teenager . It can be really bad.
But since you don't sound too confident about the quality of the tires and I don't know if they are all terrain, smooth street tires etc, I would still swap out a set for a test if you can talk someone into it for an hour or so. I'm just not close enough.
Keep us posted , I for one am thinking about this regularly. Good luck, Rob.
I was thinking tires but that wasn't it. I came here tonight to suggest throwing it in neutral when it happens and see that has been tried and that worked, Right?
Has to be under load?
So now I'm going with an exhaust drone. Not a leak or rattle , but actual resonance in the combo of the headers, mufflers resonator. I've had plenty of horrible resonance when trying to make my various Corolla Hot Rods sound cool and go fast as a crazy teenager . It can be really bad.
But since you don't sound too confident about the quality of the tires and I don't know if they are all terrain, smooth street tires etc, I would still swap out a set for a test if you can talk someone into it for an hour or so. I'm just not close enough.
Keep us posted , I for one am thinking about this regularly. Good luck, Rob.
- Thread starter
- #50
It's not even an 'under load' thing, it's really more of an 'at speed' thing. If the exhaust wasn't stock (other than the DT headers, which are well documented) I would have leaned into exhaust resonance more initially.
However - I had time Sunday to re-glue my hood with the suggested U-428. I'd say about 90% of the original glue had let go - letting my hood become a giant speaker cone at speed by vibrating at its natural frequency.
After giving it 8 hours to cure, I went for a quick test drive at 55-65mph. Definitely an improvement!! I don't think it's entirely solved yet (as I suspect my roof is just as un-glued as the hood was), but we're making progress! You can still feel some pressure resonance in your ears, but it's definitely reduced and it's not audibly as loud either now.
I'm out on work travel this week, but I'm hoping to have time this weekend to drop the headliner and do the roof. @Zuberg - if this fixes it all, I owe you a drink or two!
Also, I'm glad this will be covered up, haha:
That's great news!
Yeah, Glad your making some headway. I've seen my hood skin move in a car wash but it still has that LX/Michelin ' "Rolls Royce" quiet.
If I ever start to have a similar issue, that'll be the first thing I'll go after.
LJE, Thank you for considering everyone's ideas and keeping us posted on what has an effect. Best of luck.
If I ever start to have a similar issue, that'll be the first thing I'll go after.
LJE, Thank you for considering everyone's ideas and keeping us posted on what has an effect. Best of luck.
- Thread starter
- #54
Ugh. Just ugh.
Reglued hood. Dropped headliner - very little of the glue had let go that holds the roof to the rib structure. Went ahead and applied extra sound deadening, reglued the entire roof anyways. No change as it turns out - still just as painful.
Found exhaust leak in flex pipe - ordered that, just got it today & installed it. No change. Still painful to drive between 45-60ish. Bumps in the road (or a gravel driveway) also seem to make the ear pressure/pain happen.
For funsies, if you open your rear hatch + tailgate, then go sit in your driver seat and slam the door, that's a pretty similar feeling - except imagine that multiple times a second... Seems like a bumpy road with the tailgate & hatch open exacerbates the ear pain too, so that's interesting. No idea what that means though.
I'm super discouraged at this point. Between the initial purchase and all the OEM parts, I've put ~$23K and countless hours of labor into resurrecting this once-dead LX470 to make it mechanically perfect... and it's undriveable for more than a few minutes at speeds between 45-60.
Any more ideas guys?
Reglued hood. Dropped headliner - very little of the glue had let go that holds the roof to the rib structure. Went ahead and applied extra sound deadening, reglued the entire roof anyways. No change as it turns out - still just as painful.
Found exhaust leak in flex pipe - ordered that, just got it today & installed it. No change. Still painful to drive between 45-60ish. Bumps in the road (or a gravel driveway) also seem to make the ear pressure/pain happen.
For funsies, if you open your rear hatch + tailgate, then go sit in your driver seat and slam the door, that's a pretty similar feeling - except imagine that multiple times a second... Seems like a bumpy road with the tailgate & hatch open exacerbates the ear pain too, so that's interesting. No idea what that means though.
I'm super discouraged at this point. Between the initial purchase and all the OEM parts, I've put ~$23K and countless hours of labor into resurrecting this once-dead LX470 to make it mechanically perfect... and it's undriveable for more than a few minutes at speeds between 45-60.
Any more ideas guys?
Open up your fuel filler door and check to see if that boot is secured at both ends. If it is loose, that could let in some wind noise.
Does it change with windows open vs closed? what about the rear hatch?
Does it change with windows open vs closed? what about the rear hatch?
- Thread starter
- #56
Windows open/closes changes it a little bit, but not as much as you'd think it should. The sunroof actually seems like it has more of an effect than any of the side windows.
Does it change at all when in different gears? Maybe downshift and see if it goes away?
I had something similar on my 4Runner a long time ago when I built a custom roof rack. The airflow over the cross bars was making the roof vibrate. My solution was to pad between the crossbar and roof. I found it by going crazy with a roll of painters tape until I made a difference. You may need to try the same.
- Thread starter
- #58
Downshifting doesn't actually make a difference - it's independent of engine RPM, but definitely vehicle speed dependent.
I guess I can try shoving a rag between the stock roof rack and the roof next.
I've been on/off reading this thread, and really sorry to hear your issue persists. You initially noted
And I'm wondering whether or not something in the "exit gases" chain is the culprit. Might be worth finding a used stock system and hooking it up. To start with try stock (including cats) from the headers, which should be pretty straightforward.
