JMRedwine

I've removed all my interior panels to lay down some fat mat for sound deadening.

Is it worth it to remove the whole dash board to put it on the top part of the firewall? I can reach the lower part behind the factory foam, so how big of a difference would it make if I removed the whole dash?

Also...I don't have a factory hood insulation...can I use fatmat?

TheNerd

It is not worth removing the dash. I laid down sound deadener all over (including the door panels) up as high as I could up the firewall without removing the dash. The road noise I hear now is all due to poor weather seals (i.e. air coming in from through the window/door seal gaps), and the fuel pump. The dash itself is a good noise barrier, so you won't gain much by adding more mats to the firewall. Removing the dash is a HUGE PITA. If you find yourself in a situation where you are replacing the evap or heater core (in which a dash removal is required), then you can throw some mats in if you want...

coloradoboy

I Have a friend who has a 2001 Xj and he went through the entire car and "fat matted it" but honestly it is still pretty noisy, i would say do what you can, but dont expect perfection

djb383

Install one of those sound/db meter apps on your smart phone and take some measurements (XJ vs others).....is the XJ really that much louder than other similar vehicles?

VTJeep

90db @ 75-80. 92db towards the floor.
No carpet, no sound deadening. Headliner installed. Windows up. I've only got 235 DuraTrac's, probably a 44 series muffler and a WAI... I'm gonna work on sound deadening soon.. Got a qt. of Monstalina sitting at home, but my driver side floorboard is in need of replacement, so one thing at a time...

JMRedwine

So....leave the dash up? Ok! That's what I wanted to hear. I've the interior apart and am cleaning now. I sanded a couple rusty spots...think I need to hit them with primer, or should the seal of the fatmat be enough to keep the dangerous o2 and moisture out?


Nobody who didn't put it on the firewall and regretted it later?

CherokeeChick

What is the point? Are you just trying to eliminate road noise? Or is it to eliminate rattle
From your sound system? I'm doing the front passenger area and the rear passenger area and I'll be doing a write up I'm just Doing it because the transmission gets really hot in the summer and burns your leg! I have no carpet. And if I have enough of the shop roll left I'll probably do the doors but that's a big pita!!! if you hear back ground noise in your sound system you can wrap the wires in dynomat and do back behind your deck it makes the fuzzy noise go away.. I wouldn't do behind the dash unless your getting vibrations from your sub.

VTJeep

The door panels are an easy remove- (on my 99) it's 3 screws in the armrest and the rest is just those annoying plastic clips. Working from the bottom up, pop the clips and then push the panel straight up off the window sill. You'll find a very hollow door. Reach into the hollow cavities with some thin sound deadener and apply it to all areas you can reach. Then cover cavity holes with more sound deadener.

The rear lift gate is the same- take the plastic panel off, in my case it rattled a lot itself, and some layers of sound deadener in there. I opted to leave off the rear panel in the end.

The roof follows suit with everything else.

JMRedwine

I am at 75 db at 75 mph. I'm hoping to get it below 70, hopefully in the 60-65db range. I'm driving it 3000 miles next month and want to be as comfortable as possible!

JMRedwine

Never got an answer...Can I line the hood with dynamat? I have some left over from the car.

VTJeep

Yes. It will probably melt, but you could do it...

VTJeep

I really dont think dynamat is the stuff to use under hood. They make a may that is intended for the exposure to heat and elements.

jeepsurfer1

Plus I would guess it would hold in heat under the hood...

CherokeeChick

no, no I was talking about the inside of the doors lol big pita but it makes it sound good!!!

CherokeeChick

you can do anything you want with it lol if you wanna remove the head liner then do it lol