[Oldsguy]

I had a coil rupture and spill the coolant/oil all over the back of the engine and the driver side exhaust. That is a nasty smell that takes forever to go away.

On the subject of mis-diagnosis, I repair two-way radios and we often get radios in for repair with notes like "has a short in it" or "won't turn on" and when we check the radio cannot find a problem but the owner forgot to send in the battery with the radio and that turned out to be the problem....etc. Seen some real good ones............