Quickly, I coauthored the W126 buying advice at www.mbcoupes.com
It's a little dated now (I wrote it back in 1998) but has some of the things to look for covered still true now as then...

See also www.sec-shop.com which is a british shop also with some buyers guide tips for the coupes, but applies to the sedans also.

Don't get a refugee from a freeway pileup, a rusty one, and try to get as much service history as you can, because if there is deferred maintenance on them, they are nasty to keep up. One member bought a W126 420SEL
that needed several thousand put into it, but now SIDURI 19 "Mistress Heather) is pretty much caught up with the issues and she loves her car.

With proper care it will go 500,000 miles or more, and if you are over 100000 miles when you do the timing chain guide rails and tensioner, you might think about the injectors and motor mounts while you are at it, they might need attention by then.

Good luck to you-you'll be happy with a car like that. Price sounds about right if it is in good shape. Get the Carfax, VMI and whatever other info and history you can on the car.

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1991 560 SEC AMG, 199k <---- 300 hp 10:1 ECE euro HV ...

1995 E 420, 170k "The Red Plum" (sold)

2015 BMW 535i xdrive awd Stage 1 DINAN, 6k, <----364 hp

1967 Mercury Cougar, 49k

2013 Jaguar XF, 20k <----340 hp Supercharged, All Wheel Drive (sold)