87 Turbo exhaust leak in cab

[Solid Snake]

I have done searches on the forums for this problem, but I think mine is a bit unique so I am starting a new thread.

I have a 87 Turbo with the Lindsey racing 300RWHP kit on it. So it has a 4" exhaust and no cat.
Also, the previous owner installed new shocks for the back glass and the frame for the glass is now bent pretty bad (a common problem it seems).
So the back glass was definitely leaking as I could hear wind noise. I am poor and not willing to risk breaking the back glass so I just filled the bent part with this silicon stuff, and even some tape to make sure it was sealed.

So if I have the windows down, or the A/C running, I smell exhaust in the cab pretty bad. And that is the unique part, if I have the fan running, but the A/C compressor off and the windows up, no smell at all. I am assuming that the A/C is creating a different pressure in the cab and sucking exhaust in from somewhere. Because if I stick my nose in the vents while the A/C is running I don't smell exhaust, but the cab is definitely full of exhaust And there in lies the problem. I can't seem to figure out where the leak is. I think it must still be coming from the back glass, and that is what I am afraid of because I don't really have a way to fix it, being broke and all.

Let me know what yall think,
Thanks!

[zedsn]

I would check all the exhaust connections as well as the turbo pipe connections for leaks.

[nize]

when you have the a/c on, are you recirculating cabin air back into the cabin?

my guess would be that you still have a leak in the rear glass area, which is permitting the exhaust to enter the cabin. this is a common problem.

[UncleRay]

Originally Posted by nize

when you have the a/c on, are you recirculating cabin air back into the cabin?

my guess would be that you still have a leak in the rear glass area, which is permitting the exhaust to enter the cabin. this is a common problem.

FYI, my '87 was bringing in exhaust gas from somewhere. The rear hatch had a rattle on the passenger side. Adjusted the latch pin a little and tested again, still some rattle. Adjusted again and the rattle went away and so did the exhaust smell. The hatch still releases fine with the button on the drivers side foot panel.

[Solid Snake]

I have tried running the AC with recirculating the air and not, and it doesn't seem to make a difference.

UncleRay: I think the pins are ok, I don't get any rattle, but I guess I could try adjusting it and see what happens. I have never adjusted them before, is there a trick to it?

[Smiledr996s]

Not an easy fix but the foam under the shifter may be bad. I changed mine with only the shield removed. It was not as pretty as it could have been with more stuff removed.

There are also a lot of large rubber grommets that pop off some are in the rear wheel wells.

Also the rubber seal on the hatch may be torn or have gaps. As the seal on the fire wall.

I have been out of my car a couple yrs but was on a quest as you may notice.
Definitely try to rule out all exhaust leaks as well.

[Solid Snake]

The otter rubber seal has somewhat of a gap. Is this enough to do it? The inner one seems fine. It's just so hard to test this problem! Everything looks sealed up!
If it were coming from the shift boot, shouldn't I smell it coming from there? Because when I put my nose close to the shifter, I don't smell anything. I didn't know about the grommets in the wheel wells, I'll have to check that.

[nize]

you might be able to spray a water hose on full blast horizontally along the edges of the rear hatch to locate the leak.

[Solid Snake]

Good idea. I'll try that.

[UncleRay]

FYI to adjust the rear hatch, loosen the lock nut and turn the latch "stud" in to make the hatch close tighter. I went in half turn increments until the rattle went away. Hope this helps.