I see you have a CDI. Had the same year. Great car. Didn't like the fly by wire brakes and the nose dive on braking. Other than that, it was a great car. On your GLK check the front driveshaft u joint. It is not serviceable and is located under the exhaust. The one on my car dried out and was ready to fail. It can make a huge mess.

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63 190d (sold)
69 220D (sold)
69 280SL (sold)
76 BMW 2002 (sold)
86 190E-16v (Demised at Laguna Seca Turn 9)
87 300SDL (sold)
87 300SDL 135k
87 300TD 280k (sold)
95 E320W 211k
95 E320w 111k
05 C320 4matic
06 E320 CDI 90k (Totaled by a texting 19 year old girl in a nissan)
2013 GLK 250 Bluetek 4MATIC