I enjoyed reading Paul McBride’s article on the problem the fellow has with high EGT (Ask Paul: Is it a sticking valve? An induction leak? May 5 issue). You have some very good tips there. However the one suggesting using a soap solution around the intake area while the engine is running seems a little strange. I have been a mechanic for the last 45 years and I always thought the intake was under a vacuum (relative to the atmosphere) in a normally aspirated running engine. This would indicate the soap solution would be drawn into the leak and not produce any visible bubbles.
What I have found useful is to use a clean shop vac with a blow outlet to pressurize the intake, spray with soap solution and then look for bubbles (without the engine running!) In the automotive industry, a smoke generator is commonly used for this purpose.
Keep up the good work!
Don Gordon
via email