100,000 Miles - "Preventative'' things to do




All the inventory was sold out during COVID break so I purchased my pigtails directly on eBay from USA shipper.
only the best 😂
Check eBay item #175761587187
these harness are truly disposable and work very well for what they are.
Good quality connections.
Unless you are running normal oil pressure, your ECU has no chance to time your fuel pump accurately. Tensioners just do their thing to run the engine in full factory compliance.
> Important, not Urgent:
The ECU is the No1 top VIP module.
It can only perform as well as Lambda + Tensioners let it.
A lot of ppl love sparkplugs and injectors replacements... ignoring simple Lambda + Tensioners as business secrets.
✌️
Last edited by CaliBenzDriver; Jan 7, 2024 at 12:18 AM.




Hpfp's were right there may order those, along with the low pressure in tank . Add on find my passenger upper timing cover is leaking as well womp womp. Water pump & coolant lines are also in my wheelhouse this winter ha (coming up on 100k)
Last edited by SilverE5588; Jan 7, 2024 at 07:39 AM.




The Best of Mercedes & AMG




did you ever tune it. I remember the hre wheels.
What happen to that other guy who used to be in the forum with bunch of cars. Vic55 or something
Still have extra HRE's too that I can't sell.
Not sure what happened to vic55
On my way home at 1 AM the heater outlet valve on the back of the left cylinder broke and puked a bunch of coolant while I was on the freeway. I pulled off quickly and pulled into a gas station that was closed. Called AAA and had them tow it back to my shop. Apparently that valve has been updated by Mercedes three times. They actually get rid of the valve and replace it with a stronger standard fitting (no valve).
I'm going to go ahead and change that as well as ALL of the remaining plastic parts in the cooling system, do all of the 100k mile recommended updates, 100k service and do the timing chain and tensioners while I'm there.
Frustrating. Plastic in the cooling system... 🤦♂️
I still love it and will never sell it, but it shook my confidence in the car a little. I'm just glad it happened to me and not my wife.
Last edited by csebern; May 30, 2024 at 04:14 AM.
I'm really sorry gentlemen, I wasn't subscribed to this.
The car is a MY2012 W212.274 E63 Wagon P30. Built in 11/2011
It seems to have failed from embrittlement caused by thermal/pressure cycling.
A 278 200 21 52 FEED LINE 220 AT REAR LEFT CYLINDER HEAD 001
A 278 200 08 31 SHUTOFF VALVE 220 AT REAR LEFT CYLINDER HEAD 001 Replaced by: A 278 200 21 52
A 278 200 06 31 SHUTOFF VALVE 220 AT REAR LEFT CYLINDER HEAD 001 Replaced by: A 278 200 08 31
A 278 200 05 31 SHUTOFF VALVE 220 AT REAR LEFT CYLINDER HEAD 001 Replaced by: A 278 200 06 31
Parts A 278 200 05 31, 06 31 and 08 31 are two pieces and fail at the seam right near the label.
A 278 200 21 52 (new part) (below) is one piece, thicker and is made from a different type of plastic.
Lastly, the heater hose from the outlet to the firewall has been updated to A 212 830 23 00.
Last edited by csebern; Apr 3, 2025 at 05:20 AM.
I'm really sorry gentlemen, I wasn't subscribed to this.
The car is a MY2012 W212.274 E63 Wagon P30. Built in 11/2011
The part that failed was A 278 200 05 31 SHUTOFF VALVE, it was original to the car. It is bolted to the rear of the left cylinder head behind the vacuum pump. It provides a female water outlet that the male heater core hose connects to. It has since been updated to A 278 200 21 52 FEED LINE after being superseded 3 times!!!
It seems to have failed from embrittlement caused by thermal/pressure cycling.
A 278 200 21 52 FEED LINE 220 AT REAR LEFT CYLINDER HEAD 001
A 278 200 08 31 SHUTOFF VALVE 220 AT REAR LEFT CYLINDER HEAD 001 Replaced by: A 278 200 21 52
A 278 200 06 31 SHUTOFF VALVE 220 AT REAR LEFT CYLINDER HEAD 001 Replaced by: A 278 200 08 31
A 278 200 05 31 SHUTOFF VALVE 220 AT REAR LEFT CYLINDER HEAD 001 Replaced by: A 278 200 06 31
Parts A 278 200 05 31, 06 31 and 08 31 are two pieces and fail at the seam right near the label.
A 278 200 21 52 (new part) (below) is one piece, thicker and is made from a different type of plastic.
Lastly, the heater hose from the outlet to the firewall has been updated to A 212 830 23 00.







