Finding small exhaust leak

[Norman Connacher]

What are some of the best ways to find an exhaust leak? Trying to find it by listening does not seem to work as there is too much general noise back there to pinpoint it. It is a fairly small leak that came about as a result of installing a new muffler. I have tried tightening all the clamps and bolts and think it may be coming from where the exhaust system is attached to the heads because of misaligned flanges?

Norm

[David Jones]

Norm, buy a mechanics stethoscope from a parts store or harbor freight. Useful for pinpointing odd mechanical noises but if you use just the tube without the sound box you can then hear exhaust leaks by moving the end of the tube around the vicinity of the suspected air/exhaust leak. You could also do it by sticking one end of a piece of tubing in your ear and doing the same search around the leak with the other end.

[Mike Wilson]

New muffler? Did you make sure the flanges were flat and parallel to the heads; is it a Dansk; did you use exhaust paste on the J pipes, etc.? As suggested, get the mechanic' stethoscope and you'll find the leak. Also look for evidence of "flaming" which indicates leaks.

Mike

[John Weyand]

The stethoscope I got from Harbor Freight has a solid, not hollow pick-up tube. So it works by physical contact to hear inside noise. When I search for exhaust noise I use a length of flexible fuel line long enough to keep my hands clear of the hot muffler. By moving the end around the exhaust connections while the other end is in the ear that still functions I found the leak quite easily.

[Thomas Sottile]

If you have used the old clamps they may be stretched even new, they can be a problem use sealer if you can.

[Norman Connacher]

Thanks everyone. I will follow your advice.

Norm