Replaced trunk seal, exhaust gases (smoke) still coming in..

[Guest Anonymous]

It definately helped cut down on it, but I can still see some smoke coming in from what looks like the rear speakers mounted above and behind the rear seat, or what appears to be smoke coming from the rear seat itself(Through where your back would be located). Any other ideas?

[BLUNT]

Tail light gaskets?? holes in trunk floor?

[Guest Anonymous]

the exhaust manifold or the downpipe?

[Jack]

While I know this doesn't stop the source of the leak, a piece of fatmat across the rear deck lid will seal up all kinds of little holes that may over a 30+ yr life have been put into that lid. It can also act as a gasket for the speakers. Might even damp a bit of vibration to improve the sound system.

[Grover]

If you haven't already done so, check that the gasket is snug up against the lid of the trunk. Perhaps slide a sheet of paper between the gasket and trunk lid and slide it around the perimeter of the trunk to see if you have a nice tight seal all the way around.

[Guest Anonymous]

I will tell you from experience

to also check inside the cabine area, The reason is that if their is a hole it will create a vacum effect. Reduce Vacum and the chances of exhaust getting sucked back into car are eliminated.

[dubois]

Most exhaust problems you won't see, but you can smell. I would suggest fixing the root cause of the problem, ie stop the smoke in the first place! I chased an exhaust leak for 5 years, doing the same thing, tring to make a 30 year old car perfectly sealed to the outside! I don't think even new cars can do that! I posted, posted and posted and maybe somebody suggested what I am saying, but probably not emphatically (reason for long post), got to the point where I had to slam the trunk, that's how tight I had adjusted it. One day I taped the complete trunk with duck tape and drove it - I could still smell the fumes!

Then the apple fell on my coconut! It is not the trunk seal, it is my exhaust that is faulty! Put the car on 4 jack stands and ran it, got my hands around the entire length including the manifold (got first degee burns several times- but I was determined) and lord and behold, found a miniscule leak!

Since then, I found an easier way to check for leaks and I will share it with the board: get a propane torch and blow the flame around the exhaust system, the flame will change colors when there is a leak. Don't even waste your time with the hose on your ear, that DON'T work (shop talk for that doesn't work), we tried both methods at a muffler shop and the hose couldn't find my leak.

Good luck, I really hope that I can help a FAQ er not go what I went thru!

[Guest Anonymous]

To follow up to a post that's below:

There are hundreds if not 1000's of little nooks & crannies that will create a venturi as you drive and suck air out of the cabin. Although the air going out is OK, the air coming in to replace is now always. Your windows, window gaskets, rear windows, etc. incl. trunk seal & whatever else can cause exhaust to be drawn up into your car.

Just like with people, when Dr's constantly perscribe drugs to treat symptoms rather than look for the cause, we end up with widespread problems. If you have an issue with smoke in your cabin stop where the smoke is coming from. There are LOTS of ways to seal up an exhaust system for <$20US.

Best of luck!

[oh2fly]

One more thing to consider is the exhaust outlet. BMW put the exhaust way off to the right on pre 75 cars for a reason. It is to get it out of the highest low pressure ( vacuum ) area in the center of the car. Ever see a rear panel after a long road trip? Pretty ugly, huh? You can extend the tailpipe a little to get away from the vacuum if it is center outlet. Down side of that is the burns on your shins when you forget about the tailpipe while opening the trunk. Wanna see my scars?