Toyota Repair: Vacuum Leak

Question
Hello! Back again. Followed your instruction on my 10/15 post. So Far so good. Have "confounding " situation on 2000 Corolla.  Still have the small vibration near the engine.  Replaced motor mounts. My personal mechanic thinks a vacuum leak but cant pinpoint yet.. My friend  who was a long term Toyota salesman and works on cars thinks vacuum(maybe near the "diaphragm"). Both said may have to wait to it gets bigger. Took to Toyota for diagnostic health check they said fine but would require additional physical check. Was a little disappointed in that response. Problem is runs just a little rough but cant find the vacuum leak. Is there a specific test to find this? If it is smoke what is an average cost?

Answer
You can check for a vacuum leak using a vacuum gauge connected directly to the intake chamber, the power brake booster hose is one, any hose that comes directly from the intake is ok, most autoparts stores can loan you the gauge or you can have a mechanic check it, a good reading will be about 18"hG, a lower reading may be an intake leak or a valve leak, my next step would be to check the actual cylinder compression.