Ya' know...I really like my dealer, very good customer service and they run on time usually and I always have access to a loaner car. But sometimes I think the techs in the back miss the obvious solutions.
I had the hose from the upper tank to the radiator replaced but the level was still going down and the smell was still there. I thought to replace the fairly new radiator cap myself since it costs me about $5. I think the problem is now solved. Yesterday there was no smell at shutdown and the coolant level stayed the same.
I'm thinking about giving the service advisor a call as constrcutive feedback. This has happened once before and it involved the radiator cap again.
1994 E320 Wagon (Died @ 308,669 miles)
1995 E300 Diesel (194,000)
1999 E300 Turbodiesel (244,000 miles, dies at 255,000)
2006 Toyota Tundra SR5 AC 4X4 (115,000 miles)
2011 Audi A4 Avant (129,000 miles) hate this car!
BMW 330 xi 6 speed manual (100,034 miles)