Double layer of hoodliner for doghouse?

[campingunlimited]

I installed two 12"X20"sheets .063" Dynamat style deadener to the underside of the doghouse of my 1996 7.3 E350. I applied it to over the existing factory insulation by carefully cleaning the foil. I was surprised how well is adhered and very surprised at the noise reduction. No clearance problems at all. Much quieter but wildlife can still hear me for miles.

[Marcel Huijser]

Thank you!

[IdahoGal]

We are a day into what I thought would be a simple project: replace the single din Kenwood that had the most complex controller ever with a newer, double din Kenwood, and dynamat the doghouse, perhaps the floors under the carpet, and the front door panels. After a full day, finally figuring out we needed to Dremel the **$% out of the radio inset in the dash, we at least have the wiring harnesses switched out. We’ve pulled the doghouse and found the foil insulation a little toasted in spots as well as separating down by one corner.

I am also disappointed to find the carpet looks to be just glued to the metal floor. So removing it will be more than we are up for this weekend.

Question: should we do anything to address the issues with the doghouse insulation? And do we just apply dynamat over it? Ideas, suggestions, opinions and experience welcome.

[Marcel Huijser]

If you are going to replace the insulation on the inside doghouse:
1. get all existing insulation off
2. apply dynamat (sticky stuff with aluminum backing). This is for vibration reduction and needs to get on the "naked" inside on the doghouse, not on top of the existing insulation
3. apply hoodliner (self adhesive, heat shield and sound barrier). I got 2 layers of this material on 7.3 diesel except for a small patch where it would touch engine components.

If you want floor insulation (sound, temperature):
1. clean metal floor
2. apply dynamat (sticky stuff with aluminum backing).
3. apply dynapad (this is heavier foam, no adhesive included)

So there are basically 3 products:
1. dynamat (vibration reduction)
2. hoodliner (sound and temperature insulation for inside engine compartment: very hot environment)
3. dynapad: use on inside vehicle (sound and temperature insulation)

[Twoxentrix]

Originally Posted by Marcel Huijser

If you are going to replace the insulation on the inside doghouse:
1. get all existing insulation off
2. apply dynamat (sticky stuff with aluminum backing). This is for vibration reduction and needs to get on the "naked" inside on the doghouse, not on top of the existing insulation
3. apply hoodliner (self adhesive, heat shield and sound barrier). I got 2 layers of this material on 7.3 diesel except for a small patch where it would touch engine components.

^^^^^I'll endorse this as well - Have the same (with a 6.0 under the hood), and barely get any heat on the inside. ^^^^

[IdahoGal]

Thanks for the suggestions—I had already ordered dynamat extreme and dynapad, so now yet another purchase for the hoodliner before I can tackle this project. Will let you know how it goes.

[1der]

While you have the carpet up consider painting the floor wall to walL and up the sides a couple of inches with POR15 or similar. Avoid painting any of the body bolt heads as the POR15 will make it difficult to remove these, if ever needed.

Then you can apply your Dynamat or whatever. Keep in mind that your carpet plus wood floor plus cabinets plus gear all provide far more sound dampening where present then Dynamat. Dynamat should be focused on firewall, around front cabin area and walls - basically areas with minimal coverings. Sound deadening comes from mass and decoupling surfaces.

The POR 15 provides a hard barrier between the inevitable water spill that goes through the carpet and becomes an unseen potential rust zone. It is very difficult for spilled water to evaporate once it gets through the carpet and wood flooring.

[JWA]

1,000,000% correct on all accounts regarding treating any body sheet metal that will be covered with any sort of carpeting, rubber matting etc. I'm a huge fan of POR-15 and would highly recommend its entire system of cleaner, metal etching solution and the silver color coating as it has the highest solids content.

[IdahoGal]

Originally Posted by Marcel Huijser

If you are going to replace the insulation on the inside doghouse:
1. get all existing insulation off
2. apply dynamat (sticky stuff with aluminum backing). This is for vibration reduction and needs to get on the "naked" inside on the doghouse, not on top of the existing insulation
3. apply hoodliner (self adhesive, heat shield and sound barrier). I got 2 layers of this material on 7.3 diesel except for a small patch where it would touch engine components.

If you want floor insulation (sound, temperature):
1. clean metal floor
2. apply dynamat (sticky stuff with aluminum backing).
3. apply dynapad (this is heavier foam, no adhesive included)

So there are basically 3 products:
1. dynamat (vibration reduction)
2. hoodliner (sound and temperature insulation for inside engine compartment: very hot environment)
3. dynapad: use on inside vehicle (sound and temperature insulation)

Thanks for posting pics of your hoodliner installation on another thread, came in handy yesterday as I looked at the large hood liner and the smaller doghouse volume and started wondering how it was all going to work. Amazing how long these projects can take—all weekend. Saturday was removing all the goo from the previously half-way installed dynamat knock-off. Sunday was installing dynamat extreme and hoodliner. Not sure there’s room for a double layer—the insulation had some wear spots that looked like heat played a part. Haven’t had a chance to drive it yet to see if it makes a difference

[Marcel Huijser]

Yes, everything seems to take much longer than we think.
But... I often have to do it again because of a mistake or an improvement idea, and then it goes much faster than the first time around!

Did you do a "before" decibel reading so you can evaluate the impact?

About the space for a potential double layer; depends on the engine how much space you have. We have a 7.3 diesel.


Good luck!