Noise insulation - Dynamat

[waltsb2002]

note: I started this thread in another area (projects etc.) but just read the intent of that section, so I'll move the discussion here where I think the administrator would prefer it. Thanks to those who responded though and please delete the other thread.


Hello. I'm a new member to this group. Just found out about this site and the Yahoogroup, and have been perusing the wealth of information available.

We have a Silver with red front bumper 2002 EB E350 7.3PS diesel Quigley 4x4 with custom interior for surfboards, windsurfers, mountain bikes, motorcycles, climbing/kayaking gear, or just camping with the kids.

I have a few projects that I'd like input on, but I'll start with noise insulation. With the big diesel up front, and the cockpit sitting on top of the engine, we get a lot of interior engine noise. I just spent a bit of time, money, and effort installing Dynamat in the follwing areas:

1. double layer under doghouse
2. on underside of outer doghouse cover
3. double layer on floor under both seats
4. some spots under sonsole and undercarriage
5. all doors

Having done all this, I notice no decrease in engine noise! In fact, the perception is now that more noise, possibly higher pitched, is coming up higher through the dash than before. Although again, this is just a perception, as the doghouse and doors do seem more solid and transmit less vibrations than before.

Objectively, my Digital Sound-Level Meter recorded, before installation, an average of 75dB at idle, mid-80s while driving, and up to mid 90s under full acceleration.

After Dynamat installation, the readings have not changed.

I'm committed to fixing this, so that my wife and I can travel in relative peace and quiet (we still have the two kids, Isabella 4, and Hobbs 2...so I know true silence isn't possible), but any input and solutions would be greatly appreciated. We'll have plenty of time to meditate on the problem as we take off for the Colorado mountains next week!

Walt
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