Steven Lin

Would spraying a weak solution of soap water around the TBB and F hose and revving the engine be, at all, effective in revealing a leak? Or is it not that simple?

pattersom

The wastegate at the turbos is full open at neutral (notice how your turbos don't make noise if yuu rev it in neutral).

I tried it once and didn't get much result...then again I've also taken apart my entire intake looking for leaks and couldn't find it either.

Tried to convince a friend to ride in the front with the hood up and spray in soapy water while I gunned it...but we figured the hood might fly off

changs4

Will a boost gauge tell you that there's a boost leak?

pattersom

However, keep in mind the S4 engine varies boost depending on many factors: gear, engine temp, outside temp, engine load, etc...so you may witness max boost at one point and due to circumstance other than boost leak it may be lower at another point.

Also, S4 can operate in limp mode if they get the right ongoing DTC. This about cuts boost in half and is not restored until the engine is shut off.

Steven Lin

Thanks.