Yes there are ways. We had a 1999 Class A Dutch Star. I got some 1/2" foam that had a covering for the foam on both sides. I get it at HD. I cut pieces to fit and placed them inside the wheel wells over the front tires. I used silicone to hold each piece in place. then I covered what i could around the dog house as well. Then I covered the inside of the dog house with foam that had a foil covering on it. That helped to quiet the engine cab area a lot.
These days they have several products that are much better at reducing noise. Hush Mat is one and there are others. You can get it in several different ways and it has a sticky back. It also helps to reduce heat transfer to the cab area as well. Just Google "Engine Compartment Heat & Sound proofing material"
TeJay (Tim) Auto Instructor 35 yrs (4-yrs USAF) Liz: RN/ WBGO 2014 Vista 30T/ F-53/ CHF/5-Star/Koni/Centramatics * Bella- Golden/Cocker mix & Louie-The cat / All Retired