The 2.5 is a fantastic engine, so nothing special to look out for there. You'll want to be more concerned with W124 chassis issues like A/C evaporator and rear suspension. I'm pretty sure that car should have an R12 system, and could be a disaster if converted to R134a.

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Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
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