exhaust leak

[mr.flat6]

1981 911sc

when i decelerate the engine pop pops back through the exhaust.
Most likely an exhaust leak? How do I find the leaking spot, etc.?

Tx!john

[Vipergrün]

Hey John, could be an exhaust leak, could be your mixture is too lean as well.

I found my exhaust leak when I started the car cold and saw where a bit of moisture from condensation was blowing out.

Good luck!

[Gordo2]

I found mine ('83 SC) by getting under it while running and checking all visible welds (where tubes connect to flanges...). Had it up on ramps.

Mine turned out to be the cat converter, where the cat connects to the flange that bolts to the exchanger. It was making an anoying ticking sound like my valves were knocking.

I plan to replace the entire system with SSI's sometime (when I get beyond all my "get it in good running condition jobs...). I sealed it up with exhaust sealer goop meanwhile. It's held so far, if it leaks again prior to the SSI's I will re-goop.

Could get it welded if I really wanted to fix it, but it would require removal, and if I remove stuff it's not going back on...

Another trick is to get a piece of garden hose, hold it up your ear and pass it over the exhaust, acts like a stethoscope to isolate a leak.

Good luck,

Gordo