[amazon69]

I used a simple and really effective trick to chase down exhaust leaks on my old Merc..I used a small sprayer to wet the manifold and joins with a washing up liquid and water solution, and then put my garage vac in the exhaust set to blow. I put a rag around the hose to make a good seal. The exhaust leaks, if you have any, are immediately obvious..it works really well.