Nadine's Motorhome is Running Hot: Can Car Talk Help?

Dear Car Talk:

My husband and I own a 2002 Class C Motorhome with a Ford E450 chassis and a V-10 engine. It runs fine, but the problem is that so much heat comes from under the dashboard on the passenger side that it's hard to sit there -- even with the air conditioning on. I've been complaining about this since we bought the RV in 2003, but since it doesn't affect my husband's side of the vehicle, nothing has been done about it. This is a problem only on my side (he does almost all of the driving). Can you make any suggestions about what to do about this? Thanks.

-- Nadine

I'm guessing the previous owner's wife forced him to sell it, and that's how you guys got it. 

My first suggestion is that you start driving, Nadine. Make him sit in the passenger seat for a couple of hours, and I guarantee it'll be fixed very quickly.

You need to do a little more detective work and figure out where exactly the heat is coming from. If it's coming from a ventilation duct, then you may have a blend door that's stuck and needs to be fixed. 

More likely, though, on this vehicle, is that the heat is coming through the floor. The right side of the exhaust manifold is very close to the passenger floor where you sit, and it generates a ton of heat. The so-called "doghouse" -- the engine cover between the seats -- also is a source of heat. 

So my suggestion would be to insulate both of those as best you can. Have a mechanic remove the carpeting, and add a couple of layers of insulation between the floor and the carpet. You even might want to try to find something called a heat mat, which is specifically designed to block heat. I'd run that insulation up the outside of the engine cover, too. 

My guess is that it will improve the situation. So you can at least switch from halter tops to tank tops, Nadine. Good luck