Well, at almost 221k miles the 13 tear old coolant expansion tank finally ruptured at the seam between top and bottom at the start of the week. Amazon.com to the rescue, 15 hours later, not even on “Prime” the new OEM unit arrived. Tonight after examining the new tank it took all of 3 minutes to swap tanks, top off with genuine MB glycol and be done, loosing very little. If you have a high mileage W211 like my 06’ e320 CDI it’s definitely worth a check. My old one I was literally crushing the edges with my fingers over trash can and wadding up the plastic shards for disposal. Since the turbo diesel commuter cars are much cooler under the hood than the gas models, if you have one of those, it’s probably good for significantly less lifespan.

Easy DIY fix, hemstats, a large it of players to do hoseclamp, and a single #2 Phillips screwdriver. Did even bother to take pics, that easy, if there is interest I can take some next removal at new intake manifold time since it will be coming back out. New manifold is flapperless, up pipe EGR Venturi removed, no EGR coolers box, ported to match head, media blasted inside and out...and probably should be painted before installation, of water injection and extra IAT/Pressure ports too.

Scheduled major service including new water pump, thermostat and such is only about a month away...newest version of intake manifold going on then, been trying to think of something creative to do with coolant lines left over from old EGR cooler, maybe a fuel preheater? Probably pointless but I do burn a small percentage of WMV and JetA in many tanks I get for free?