I occassionally hear a high-pitched chirpy bird-like noise, which I think might be the turbo, at the top of the gears range (just before the transmission shifts to the next gear). Turbo? Problem? The car performs fine...lots of power, 0-60 is 14-16 seconds...never really timed it but it seems powerful. Fast enough to pass Prius' on the hwy, etc.

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1982 240 D, 308,000 - 321,127 miles (sold)
1982 300 TD,166,500 - 226,000 miles
1998 E 320, 120,000 - 144,000 miles
2005 C 230 K, 26,000 - 77,000 miles (sold)