What year is the car? What have prior mechanics diagnosed the problem as?
1980, roadster 450SL.
It all started when I moved to Vegas.
The first repair shop was great but Sig Autohaus has retired, he did change seals and gaskets. Car had no leaks and he fixed them all. He changed the cam shaft too. The car was running like a charm after Sig worked on it.
Later on, I changed all 4 tires. A couple weeks later I had a little noise on the back right side of the car. I didn't think of the tire, I went to a German car repair (SIG HAD CLOSED his shop). They told me it was the full pump that needed to be changed, then all the hoses under as well.
From that day my gas mileage and smell started. I returned to them they told me there were no problem with the full pump, charged me the $110 for the check up.
I had the tire repaired a the tire shop a few days later, it was not mounted properly and was flat every so often. The noise might have been just that.
Later on I had the car overheating, same repair shop changed the coolant bucket. Car was still overheating and I decided to go to another repair shop german car shop. They kept the car almost 6 weeks and I returned it 3 times. They changed the aux fan, the intake manifold, changed all the hoses in the engine.
I Got the car back, car was still overheating, they kept it a few days, when I took it back, I got stuck again, car overheating and shutting off.
I requested a thermostat change and coolant change.
From that day on, the car has been smelling gas, getting 2 miles per gallon, smoke coming out, black powdery stuff coming from the exhaust.
I went to the shop to tell them how unhappy I was and my car was a mess and they all tell you that what they did on the car couldn't create my problem.
My car has passed the emission test for 8 years, only this year it failed because these guys messed it up and I am certain of that. My car was serviced in San diego CA for years and was always running fine, moved to Tampa FL car was serviced by a german guy, excellent mechanics.
What could have created that mess ?
I have ordered the DVDs on how to repair this car. I need some good advices on troubleshooting.