exhaust smell

[zKars]

Some one actually did a smoke pressure test in their Z (fill interior with smoke, seal and pressurize, watch where it comes out) they were so desparate to find the leak. There were leaking body panel seams in the rear of his car.

I can vouch for that one on my 73. I'm in the midst of stripping the undercarriage and now that the undercoating is gone, there are a couple of obvious seam seal "boo boo's" from the factory where the goop was left a little short on a couple of seams. Nice...

Here's my list of where to look, and places that need attention (and that don't)

-Tail light gaskets

-Antenna drain grommet and the antenna mounting hole itself.

-Hatch seal weatherstrip.

-Gas fill hose grommet in hatch deck

-Vapour line grommet next to and ahead of the filler tube.

-Gas tank vapor line grommets at the rear that pass through the hatch floor.

-Drain hole plugs in spare tire well

-Hatch hinge boots

-Rear marker lights. Rubber seal on the body, cracked/loose lenses?

-The hatch is full of holes that can allow outside air into the void within the hatch structure. The only barrier to the interior of the car that is inside the perimeter of the hatch seal itself, is the glass weatherstrip and the rectangular vinyl trim panel that mounts with 10 rivets/screws. It's old piece of dry crumbled foam seal tape is not doing its job and this panel if very often warped making a seal pretty tough. This panel should be replaced or the seal re-newed. You guys with the early vented hatch panels that aren't perfect are nearly screwed here....

Do not worry about the two 1 inch holes w/rubber plugs on either side of the hatch latch or the dovetails on the sides. With the hatch latch being a big open hole, their condition is irrelevant. Concentrate on the hatch trim panel and the glass weather strip.

I think the likelyhood of any of these being the culprit is at a maximum at the very rear near the exhaust side, and falls rapidly as you move to the right and toward the front of the car.

Even things like the rear strut mounting site at top of strut towers don't have any real seal to the outside world.

And I should mention the possibility of a leak further up. Small engine bay exhaust leaks and imperfectly sealed holes in the firewall... Say no more say no more...

And lets not even mention all the rust related voids that are lurking in places you'de rather not know about..... Ewwwww....

Edited February 16, 2012 by zKars