I read recently where someone had installed sound proofing and heat barrier material to their doghouse, and it made a considerable difference in both heat and sound.
On the Mirada, I don’t recall objectionable sound or heat from the engine compartment. The engine noise was there, but not loud. As for heat, we do the majority of our travel in winter and it seems like its always cold on the drivers side, yet hot on the passenger side. I could put my hand on the engine compartment, it wasn’t hot, but seemed like it was warm.
The original doghouse on the Mirada is reasonably heat and sound resistant. Its molded out of a epoxy/foam material that offers sound and probably a lot of heat isolation. The doghouse cover doesn’t get a lot of heat as the engine compartment is large and open to the air. Not like a class C where the engine sits in an enclosed compartment.
INSTALLING MAT MATERIAL
The self adhesive Dynamat comes rolled up in a large sheet (32″ x 54″).
Clean the doghouse surface to remove any grease oil dirt..
To cut the mat, I laid it into the doghouse and used a black marker to draw lines on the mat where to cut to make it fit. I cut the mat into several pieces that fit nicely together and covered the entire inside.
DARN GOOD ADHESIVE – DO NOT remove all the backing then attempt to lay the mat. Once the adhesive touches something, that’s it, it isn’t coming off. If you make a mistake, just cut out the bad section, cut a new piece and stick it on. Use the aluminized tape to cover seams.
Start in a corner, pull the backing off as you lay the mat down. If the backing tears, stop and remove the torn pieces before proceeding.
Once all the pieces are installed, use aluminumized ducting tape to cover the seams and edges.
This project took about 1 hour. When finished, I went for a short drive. WOW – what a difference in sound. I don’t think I had a heat issue, but it should also help, especially on those hot days when we travel)
OTHER SOURCES OF SOUND / HEAT
Last month while working on the side wall problem (read here), I stumbled on several large openings at the very front of the engine compartment. While standing on my head under the drivers seat, I could fell a strong cold draft blowing all the way forward where the engine cover meets the firewall, just to the right of the gas pedal. The wind was blowing outside and it was cold. I found two large openings, in the engine cover are, one of them was almost 2 inches by 4 inches. I just found the reason why the drivers side floor was always cold. It wasn’t from lack of heat, it was this large opening.
I couldn’t see the opening, but could put my hand in it. I used a can of expanding spray foam and squirted the two openings full of foam. What a BIG difference.