The intercooler would have had smoke going through it because you pressurized at the turbo inlet Very quick test to find a boost leak, you couldn't hear it when the engine was reved up, you had to drive it under load, and that made it impossible to know where the charge air leak was coming from. If you have smoke from the hot air intake, i would bypass that and go directly to the turbo (inlet), forget the intake hose, it can't cause a boost leak (just unmetered air intake which will mess with maf readings).
Boost Leak Smoke Test at Holly Claxton blog
When in doubt, smoke it out
The best tool you can have in your arsenal to find a boost leak on your bmw is a proper smoke / leak tester.
Boost leaks can be more than a nuisance I built this today and used to track down a couple leaks that were causing low boost and smoke under acceleration. First we need to know some of the basics You may have some questions like
Why are we boost leak testing What is the boost leak tester really doing when we. Symptoms of a boost leak 🚩 hissing/whistling noises under acceleration Sluggish throttle response or delayed boost
Check engine light (codes p0299, p2262)
Excessive black smoke (diesel engines) Overheating turbo from prolonged overworking So i'm looking for opinions on this approach to finding a boost leak Would using a evap smoke leak tester on the charging system work
Maybe making a plug in the intercooler boot with a hold for the evap machine and running the smoke trough it Smoke testing for boost leaks When chasing boost leaks, the humble and effective intake pressure test or smoke test is often used Pressuring the intake, then spraying soapy water to look for bubbles, or using a workshop smoke tester will give a visual indication of boost leaks
Unfortunately, the results may not always be what they seem.
