Too much oil?

Question by REHarris posted 6 months 1 week ago in 2003-2009 (W209)

When I change the oil and filter, my 2008 CLK 350 (W209) says it is full at 7 liters. Specs say this engine wants 8 liters. If I put in 8 liters, it blows the camshaft seals within about 500 miles. If I put in 7 liters, it runs fine, doesn't complain about low oil, and still blows the seals after about 900-1000 miles. Anyone have an idea why this engine says it's full at 7 liters? Or why it just keeps blowing the seals out? I bought it used with 99,000 miles on it and it has 107,235 miles on it now.