Somewhere in my engine (that is, my car's engine), I have a vacuum leak,
probably, and I can't find it and it seems a smoke machine is the most
reliable way to find it.

Machines sell for $100 to $900, and I posted a video on how to make one
for about $30.

Another video suggested using a vape pen!

Looked at 5 vape webpages and only one item on one page didn't require
buying the pen and the liquid separately**, usually totally separately,
from different sources. Fortunately, the one exception was also the
cheapest.

Just $11 plus 1.30 excise tax plus $13 shipping, about $25.

**Not counting disposable fruit-flavored, which are illegal to sell in
Maryland. Not by mail or in person.



The email said it would be USPS Priority Mail and pointed out that
delivery would have to be IN PERSON signed for by someone over 21 years
of age.

My upstairs doorbell is broken and I can't hear the downstairs doorbell.

Do you think the mailman will leave the package without a signature, or
will I have to wait to the next day or pick it up at the post office?