AT_Viper

I have been browsing the forum for DIY full system coolant flush as I have to do a thermostat replacement and my vehicle has just rolled over 81,000 miles. I know that it is not necessary to complete the thermostat replacement but its a feel good for me as the coolant currently in the system is green/blue and is at least 3 years old if not original.

My first question is:
Does anyone have information on a full system coolant flush? I have seen a few other DIY from other forums as well as other model MB's but not the M271 engine. I have seen the radiator flushes but I am looking for full system flush with information about volumes retained in the heater core so that I can achieve the appropriate coolant mixture. (changing coolant from green to orange (Zerex G05))

Second question is:
Since I am draining the coolant and my vehicle is approaching what I consider to be the failing years (80,000+ miles) when original parts start to wear out. What else would be worth replacing? Water pump, belts, pulleys, timing change, sensors, etc....?

I am hoping to compile this information into a "Full System Coolant Flush DIY"

Any information is much appreciated.

Thank you,

Wodeshed

I just did mine, although it was on a CLK 320 (same setup as the C class) at 140k miles. It's a no-brainer. I followed instructions as described here: http://tinyurl.com/ojgls7j

Good luck finding someplace to take your old coolant though. Parts stores here only accept oil.

FYI, my coolant looked perfect (blue), and for all I know it was original to the car, which is a 2005. I bought it with 65k miles, and again it's at 140k now and runs like a top.

I get your question about other things that might need to be changed, but I didn't do anything but the coolant. Hoses, radiator, thermostat, etc are all working fine, so I figured why change em?

AT_Viper

Thanks for the link. I will attempt to follow the procedure and document the volumes for the M271's although it should be close.

Yeah, I'll have to figure out what to do with the old coolant.

Thanks for the info.

turbonos7

When I replaced my thermostat, the plastic housing in which the thermostat mounts into turned out have broken in place. The break was on the section inside the engine where the big O-ring goes around its ouside. It was a pain in the butt to remove as everything in there is brittle plastic from all the heating/cooldown cycles. I was lucky to have tried this on a Saturday when the local parts department was still open and not on Sunday because I would not have been able to get the part and put the car back together the same day. Part was around $30 so I don't think it's a bad idea to replace the housing at the same time as the thermostat. Another part that jumps to mind is the little nipple on the engine side that connects to the small hose that goes to the coolant system expansion tank. That little $10 part can leave you stranded. I was on the road at night and stopped to replace a burnt out passenger side headlight bulb (trying to be safe) and in the process bumped that hose/pipe which caused the nipple to crumble to pieces, leak coolant and compromise the coolant system. My thermostat was original and I changed it at 140k miles. I broke off the nipple at around 120k miles.

AT_Viper

Upon further review of the DIY "2014 Coolant Flush" by Scottonfire. I can only assume that the DIY was created using his "listed ride" a 2005 C230. The title is misleading as it stats 2014 and the body text of the DIY makes no mention of the year or model vehicle. It appear this is a full Coolant Flush DIY for the M271 engine.

I would like to give proper "kudos" to Scottonfire for a wonderful DIY! This is in no way a knock Scottonfire.