Crystalworks post is spot on.

If I had BMW or an Indy maintaining my vehicle, I would expect a full coolant system overhaul every 100k to 120k miles. Shops that don't take that approach look bad when a system failure occurs within a year or so after replacing a part in said system.

Looking under the hood regularly and DIYing allows the option of replacing part near failure (this, and knowing to STOP DRIVING/CHECK UNDERHOOD when certain lights come on).

Just curious trader4, is the 30yr old MB a daily driver? Operated in ice snow? High miles?

Sorry for all the strawmen in this post!

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'03 X5 4.4 Sport, last of the M62s (8-03 build date)
I believe in deadication to craftmanship in a world of mediocrity!