I am solving an issue with exhaust getting into the cab of my '65 Coupe, but am confused about something. So, forgive my stupidity on this...

The problem is worst when the car is moving, and when the windows are down. How can exhaust coming out of the back of the car seep through the trunk (I do have some openings and cracks that are being filled) and into the cab? And why when the windows are open?

It is bad to the point I get dizzy when driving. I have had a full diagnostic done on the exhaust system from headers to pipes and no leaks. Nor is there any leak in the engine compartment. There are gaps around the seal where the gas tank lip meets the trunk floor, and there is one quarter-sized hole in one wheel well on the driver side.

Thanks.

 

I'm having the exact same problem with a 69 coupe. I have an exhaust leak at the flange that connects the header to the exhaust pipe that I'm trying to solve. I get lots of exhaust in the trunk through a couple of holes I stuffed with rags yesterday. It gets worse the faster I go with the windows down.

 

Where does the exhaust exit the car? Fumes can get sucked back into the car, even when coming out at the rear. Check the trunk seal.

 

Brand new trunk seal. Two pipes out the back, both clear the back bumper.

 

Does opening the fresh air vents help at all?

 

No. It is almost like opening the windows draws exhaust into the cab. I am going to reseal around the fuel tank, replace the filler hose, gasket and clamps.

Should the trunk be completely sealed off around the back seat and rear deck tray, too? Took speakers out that didn't work, so the tray holes are still open.

 

No the trunk shouldn't need to be sealed off from the cabin and really.. you cant. What you want is to ensure the trunk is mostly sealed from the outside of the car. Have you replaced the strip-calk that seals the fuel tank to the trunk, replaced the trunk lid rubber, etc.

Also how is your exhaust system assembled? Is it pieced together and clamped or welded at all joints? If clamped you could have exhaust seeping up through the trany shifter opening. As already stated check the header to exhaust pipe flanges.

If your driving and its so bad that your actually getting dizzy this is a very serious matter. If its that bad the fumes even over a short period can cause big health concerns. You might want to think about taking it into a shop and having them put it up on a lift to really look at the system.

 

Going to seal the fuel tank as soon as I can find somewhere that has the damn strip caulk!!! Can't find it at any local stores and the auto supply places look at me like I am crazy.

Trunk rubber is new.

Exhaust is welded, and mechanic ran a leak test from headers to pipes. Nothing.

 

Jeeze, Strip Caulk should be easy. Glazier Nolan stocks it.

Just because the trunk lid seal is new doesn't mean it's sealing anything. Put a $1 bill on the seal and close the lid. Pull on it. If it comes out easily, you have no seal.

 

Is this it?

http://www.homedepot.com/h_d1/N-5yc1...atalogId=10053