Exhaust in Blazer

[brojoe]

I have a 1971 Chevy Blazer 2WD. lowerd a bit. It is a well insulated vehical with no wholes in the floorboard.
While easing down the Highway (65-70 mph), with my A/C on, I get exhaust fumes in the truck. My exhaust pipes run out the sides in the back (Stock).
Whazzzz up???
Is this common with the older style rear window or what ???

[lks dcvn]

not common - especially at cruising speeds - is there a leak at the manifold?

[brojoe]

I do not hear any exhaust leaks.
Not to say there are none.

[Tom Vogel]

When I was driving my 72 2wd (before I started the restoraton teardown), I had the same problem...it was awful. I found small holes in the exhaust. I replaced the exhaust, and .. problem solved. I suggest you take a rea good look at the exhaust (get underneath and thouroghly inspect).

[vtblazer]

Very common at speed if everything out back isn't buttoned up correctly.

Do you have a gasket on the bottom of the tail gate?
* Very Important!

Do you have the gaskets running up the sides of the gate?
* Very Important!

Is the upper tail gate seal good?
Are you running the metal srip on top of the tail gate?
Both also very important.

If your not 100% sealed up, you'll get exhaust fumes inside.

[hotrodhomi]

Originally Posted by vtblazer

Very common at speed if everything out back isn't buttoned up correctly.

Do you have a gasket on the bottom of the tail gate?
* Very Important!

Do you have the gaskets running up the sides of the gate?
* Very Important!

Is the upper tail gate seal good?
Are you running the metal srip on top of the tail gate?
Both also very important.

If your not 100% sealed up, you'll get exhaust fumes inside.

I agree. Although, if you take the top off the smell will go away.

[brojoe]

Originally Posted by hotrodhomi

I agree. Although, if you take the top off the smell will go away.

Thank you for the replies.
This gives me two items to look at closely. Exhaust system and tailgate seals.
The rattley rear window is where I will start my investigation.

Brojoe