Well once again this 1996 Q45 is in the shop.

This time a def miss firing , so back to the shop.
Tech said they found water when they removed one of the spark plugs. No way water got into the engine area from the outside.
Tomorrow they will check all the spark plugs to see if there is water there as well. They seem baffled and the estimate is 1500.00.... They have worked on this Q for many years and seem to know what they are doing.
I have no knowledge of mechanics sot leave it up to the service people,

Owned this since new and have put over 25 grand in this Q for needed repairs, which really isn't that much .
Any thoughts.

Hi Sandy-
I got your email also, but thought I'd first reply here for greater visibility.
My question (for clarity) would be: they found moisture after removing the coil/rubber boot (spark plug still in engine)? Or inside cylinder (after plug removed)?

Moisture around the coil boot can certainly provide an unintended path (not thru the spark plug), which could indeed cause a misfire.
Would be most noticeable under load and part throttle. You'd probably never know with it idling unless there was a lot of moisture.
Moisture around the plug boot not impossible, especially with the heavy SF rains this winter? 35 years ago I would sometimes wash and detail my engine (before the Q obviously), and on more than one occasion I got enough moisture to cause the miss.
If it's just "car wash" moisture, a hair dryer will get you back in business. Recommend a small amount of dielectric grease at the tip of the rubber boots (actually NOT where electrical contact is to be made) so that there is a nice seal between the porcelain of the plugs and the rubber boot.

If there's water inside the cylinder (most unlikely in my estimation without a blown head gasket), then she might be toast.