I have a 2008 C300 with 36000 miles on it and just noticed that when the car is started (cold start) that alot of blue smoke is coming out of the tailpipes. It lasts for 3 to 5 seconds then goes away, but leaves a big cloud of blue smoke. Why would this be happening?

 

Blue Smoke: Blue smoke is caused by engine oil entering the cylinder area and being burned along with the fuel air mixture. As with the white smoke, just a small drop of oil leaking into the cylinder can produce blue smoke out the tailpipe. Blue smoke is more likely in older or higher mileage vehicles than newer cars with fewer miles. How did the engine oil get inside the cylinder in the first place? The car has many seals, gaskets, and O-rings that are designed to keep the engine oil from entering the cylinder, and one of them has failed. If too much oil leaks into the cylinder and fouls the spark plug, it will cause a misfire (engine miss) in that cylinder, and the spark plug will have to be replaced or cleaned of the oil. Using thicker weight engine oil or an oil additive designed to reduce oil leaks might help reduce the amount of oil leaking into the cylinder.

 

Doesnt this seem kind of odd to be happening on such a newer model car with only 36,000 miles on it? How come it does not smoke every time its started? It only smokes when its first started after its been sitting for many hours or overnight.

 

Looks like you have really tiny gap somewhere and takes time while enough oil leaks into cylinder to show smoke at exhaust.