I have a '91 300D 2.5Turbo (W124) with 210K, that I got from my late grandfather.

I love the car. It's comfortable, handles great and gets between 29 and 33 mpg city/highway. Mechanics tell me that, compared with other 300D five- and six-bangers, it rips.

Unfortunately, the 300D has cost me thousands to repair.

The injection pump was ruined by an ignorant mechanic attempting to fix a leak, which cause a cylinder to become starved for fuel, which caused it to blow -- which forced a rebuild and purchase of a rebuilt MB-issue pump.

The handling also went south; for awhile it felt like I was standing in a canoe at 75 mph. To fix the problem, I replaced the shocks and some linkages before discovering I needed new suspension and differential subframe mounts. End of yaw.

I also replaced a window regulator and a headlight wiper motor, not to mention a cam and two glow plug regulators (again, bad mechanics).

The car now runs like a dream (though you can tell, by my omitting the cost of maintenaince, I'm somewhat embarrassed by the expense). I'm told its aluminum-head engine is a complete redesign of older motors; in fact, it doesn't resemble them. The only concern is overheating, and ruining, the head.

As for 5K oil changes: Don't worry. If the owner used a CH-4 rated oil made to handle the soot and heavy metals of a diesel motor, they should be no problem.

Good luck on your purchase.

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'91 300D 2.5 Turbo 330K
'00 VW TDI Golf, 190K
'67 BMW R50/2
'73 Norton Commando Interstate