Duke I agree with you 100 percent!I think to become a decent mechcanic you must learn to reconize coincidence. An example you put a shot of Trans X in your ageing tranny and a week later it goes South, blame the Trans X? no in all probability just coincidence.

In the late eighties I worked the front desk of a busy import repair shop.A lady brought a late seventies 810 Datsun wagon that she used on her paper route for a complete brake job, (new rotors calipers ect) She was very pleased with both the cost and her renewed brakes.

About a month later she came to the shop breathing fire.She cursed and yelled and at one point I thought she was going to attack me .The owner of the shop came out front and she started yelling at him that her differential had gone out and we were to blame as we were the last people that had worked on her car,nothing we said could calm her down .I finaly called her husband at work and he came and settled her. I'll bet a new rotor for a 560 SEL that this is familar to you shop owners and techs.A long way to say that your oil level and starting problems are not related............
William Rogers.......