2003 C230k M271 - coolant leak at back of engine
I found the part!!!, Febi brand for $25.00. I am going to take the plunge and give this part a try.
http://www.ebay.com/itm/131683586336...witem=&vxp=mtr
I found the part!!!, Febi brand for $25.00. I am going to take the plunge and give this part a try.
http://www.ebay.com/itm/131683586336...witem=&vxp=mtr

Besides the dealer, there are many choices (you guys are lucky in USA). RMEuropean, FCPEuro, ECS Tuning, AutohausAZ, and Pelican come to mind. AFAIK, the sedan and coupes have the exact same engines and powertrains. Nothing to worry about there.
The pictures on this site haven't shown up properly for years on my computer. If you figure this one out please let me know.
Thanks for your time & this thread.
I have I believe the same mysterious leak.
Already replaced the coolant reservoir & the nipple on the manifold above the exhaust.
Ordered up the other 3 today...
I'd appreciate a quick response as time is of the essence on this- my car had lots of work done and days after picking it up a leak from this pipe left a big puddle on my driveway. Seems like too much coincidence. Any possibility that they may have damaged this pipe, collateral damage when making other repairs? Here's the list of parts replaced:
Engine vent hoses
Camshaft Adjustment Solenoid(s) and Adapter Harness(es)
Intake Manifold R&R
Crankshaft position sensors - Ignition Syst
O2 Sensor- Front of Catalytic Converter
O2 Sensor- After Catalytic Converter
Wiring harness - for engine
Position Sensor
Electrical Wiring Harness
Starter Line
Flange Gasket
TS Electrical Wiring Harn
Exchange Control Unit
2 different Sender Units




The only thing I had to move out of the way was this rigid plastic pipe at the top of the engine, that's connected to the vacuum pump. After that it was just carefully lowering a ratchet into the crack between the engine and firewall and undoing the single bolt holding the pipe in place.
I described how to replace all 4 plastic pipes on the engine if you scroll up and read the entire thread.
Last edited by slammer111; Dec 14, 2017 at 05:44 AM.
The only thing I had to move out of the way was this rigid plastic pipe at the top of the engine, that's connected to the vacuum pump. After that it was just carefully lowering a ratchet into the crack between the engine and firewall and undoing the single bolt holding the pipe in place.
I described how to replace all 4 plastic pipes on the engine if you scroll up and read the entire thread.
Thank you Slammer! Any thoughts on all the repairs done? Are those parts located in the area of the water pipe? Any possibility they may have accidentally damaged the pipe when replacing any of the parts I listed?
The Best of Mercedes & AMG
Also the manifold.
The supercharger usually has to be removed to replace the harness which is all located at the water line/pipe.
Probably needs changed anyway.
Why did MB ever decide that plastic water pipes working @ 200 degrees was a good idea?
Dealer broke the plastic valve behind the supercharger when this was just done, I had to pull the intake to fix this myself as they would not accept responsibility.





In your case, none of the repairs you listed (to the best of my knowledge) involve reaching that far down the back of the engine. It would be possible if you were asking about the plastic pipes on the exhaust side of the car (ie the R side), but this is not the case.
My pipes all blew up in 2015 and my car is 2003 (ie 12 years old). Your car is 2005 and now it's 2017. Notice a pattern?
Last edited by slammer111; Apr 13, 2020 at 06:07 AM.




Last edited by slammer111; Mar 21, 2018 at 02:58 AM.
tl;dr = What’s the triangle-shaped extra bit that came with my replacement Oil Cooler Water Pipe (A-271-200-13-52)?
SO thankful for this post. You guys saved me a lot of frustration & money spent on topping up coolant all the time.
I wanted to remove the part & double-check the P/N, but I was afraid of all the other components people said they had to remove in order to get to this pipe. I’m either lucky or stupid, but I decided to just go for it & try to remove the pipe without removing anything else.
I had a pretty easy time getting my hand wiggled between the other hoses that make getting to this pipe difficult. My palm-sized articulating ratchet slipped right into the correct space, and made getting the ONE BOLT that holds this thing on easy to remove. (If MB would’ve added another bolt 180° opposite, I’m sure these wouldn’t fail as often)
Total time = 10 min. (+15 min spent looking for something to catch the leaking coolant under the car)
Like many of you, I found I did have a cracked pipe at the o-ring (which was stretched out)...BUT...mine was so brittle I couldn’t put it back on after I removed it. This little Merc is my daily, so I was in a bad place.
I used some Gasket Maker (sold at all the local parts stores) to create a stop-gap solution while I waited for the new part I ordered to arrive. It worked! For about a month, actually....but I’m now experiencing coolant leakage just like before, so it’s time to put the new part in.
BUT!... I don’t know what this extra triangle-shaped boy is for. I’m sure it’s staring me in the face & super obvious, but I’m just not seeing it. A little help?
Also: I’m reusing the hose clip. It’s easy to swap onto the new part: Just pop the inner rod out using an awl/screwdriver/nail, or, in my case: a letter-opener.
Last edited by snobrrdr; Nov 6, 2018 at 01:35 AM. Reason: Adding photos thatbdidnt appear before.




Last edited by snobrrdr; Nov 7, 2018 at 05:26 AM. Reason: Janky looking link removed
same conclusion.
Ten bucks says it was a piece of something else that somehow got mixed in by mistake - and then repeatedly included with every additional casting.
The fitment wasn’t GREAT. It was OK. It wouldn’t slide in with the included O-ring. A smaller and thinner O-ring did the trick, though.
To be fair to the mfr: Do you see that little ridge of stuff in the hole in my pix? Pretty sure that’s leftover gasket material from my temporary DIY fix. I scraped more off after I took the pix, but it’s such an awkward spot to reach. Who knows if I scraped it all off. It was 4am. I didn’t even bother taking another round of pix. I’d already wiggled/jiggled/screwed/unscrewed the thing so many times...I was fresh out of f*cks to give. It’s entirely possible the unit would’ve fit perfectly the 1st time (with the included O-ring) were it not for me jizzing 40 ounces of gasket goo all over that hole.

I also noticed that there is a small restriction in the pipe. Would have sucked if it came loose and started circulating
.
I used a standard ratchet and (once the hose that is clipped on the plastic hose is detached) it worked fine.
I actually managed to get both my hands back there too!
I got the part from Amazon here for $13
But after 4 plus hours finally accepted that the supplied O'ring was too thick and bought this O'ring hit for $11 With the right o'ring, it is actually 15MIN JOB!!!
So here are my arm positions as I lay on the engine
My hand could reach all the way down!!
I undid the hoseclip and clamp 1st. Do Not try and remove the Host clip with force, there is a pin holding it in.
Last edited by JasonMB; Dec 2, 2018 at 02:49 AM.
I recommend the hose clamp set, too. I found it really valuable. Before I diagnosed the plastic water pipe, I changed out the coolant expansion tank because the connector there had broken. It was made of the same material as the failed oil cooler pipe.
I got rid of that crazy hose-to-metal-pipe-to-hose nonsense that goes from the cylinder head to the expansion tank. I replaced it with a cheap hose from Autozone, replacing the old clamps with new ones along the way.
Oh...and the adapter!! Ugh.
Same material there, too. That tiny little piece of expensive plastic ($80 at my dealer, but only $9-$16 online) can render your car immobile, so I highly recommend changing that as well. In fact, buy 2 just to have one on-hand, just in case!
For anyone reading this who just bought one of these older W203 C230Ks:
A) FCP Euro offers a LIFETIME GUARANTEE on all parts. I don’t work for them, I just trust them a lot more than Amazon or Alibaba.
B) Replace the items below asap because they’re due to fail after ~12-14 years:
2712001352 - Water Pipe
https://www.fcpeuro.com/products/mer...des-2712001352
2035010025 - Coolant Recovery hose (personally, I think this hose is a dumb design, so I made my own. See pics)
https://www.fcpeuro.com/products/mercedes-engine-coolant-recovery-tank-hose-c230-mer-2035010025
Note: I believe this comes with the adapter.
Alternative to Coolant Recovery Hose
Some tubing and...
0039970689 - Coolant Recovery Hose Adapter
https://www.fcpeuro.com/products/mer...tor-0039970689
2035000049 - Expansion tank
https://www.fcpeuro.com/products/mer...k-2035000049my
2105010715 - Expansion tank cap (updated part number. Old: 210501515)
Old: https://www.fcpeuro.com/products/mer...cap-2105010515
New: https://www.fcpeuro.com/products/mer...500-2105010715
2712001552 - Water Pipe, oil cooler to cylinder head
https://www.fcpeuro.com/products/mercedes-water-pipe-c230-2712001552
2712000015 Thermostat + O-Ring
https://www.fcpeuro.com/products/mercedes-engine-coolant-thermostat-2712000015
2003-2005 Mercedes C230 Cooling Hose Connector - Genuine W0133-1898545
https://www.partsgeek.com/x7bh83n-me...connector.html
https://www.amazon.com/OES-Genuine-Cooling-Hose-Connector/dp/B0047PZXC4
By any chance does anyone have the tools at home to reset the SRS... I kinda disconnected the Airbag.
That looks complex. Are you swapping out your center console?
Also: kudos on your pix. They’re really well done. I can’t even get my crappy pix to upload. ...and I work in tech!






