M271 Leaking Cam Sensors
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From: BC, Canada
2003 C230K Coupe Orion Blue
M271 Leaking Cam Sensors
Hi All,
As you may know, certain builds of the M271 (officially at least; I'd imagine ALL M271s are affected) have the cam sensors leaking motor oil all over the wires/harness. There is a TSB out for this.
MB has some kind of fix for this, which includes replacing the sensors and adding some additional wiring to isolate the problem.
For those who have had the TSB fix done, can someone please post ALL the part #s (and descriptions) off the invoice? I am looking at my invoice and am suspecting my SA screwed me.
Thanks!
As you may know, certain builds of the M271 (officially at least; I'd imagine ALL M271s are affected) have the cam sensors leaking motor oil all over the wires/harness. There is a TSB out for this.
MB has some kind of fix for this, which includes replacing the sensors and adding some additional wiring to isolate the problem.
For those who have had the TSB fix done, can someone please post ALL the part #s (and descriptions) off the invoice? I am looking at my invoice and am suspecting my SA screwed me.
Thanks!
Last edited by slammer111; Jan 14, 2008 at 10:04 PM.
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Mercedes
2x 271-150-27-33 - Isolating wire
2x 271-051-01-77 - Cam sensor
The problem with the TSB is that it only references certain engine builds. Mine is 740 and the TSB only referenced 744 (or vice versa, I forget), yet ALL M271 use the same cam sensor, I had the parts department check other VINs to see if there was an updated part #.
So ALL M271 will eventually see this failure.
Please, if you're keeping your vehicle get these wires and install them. If you're under warranty they will not pay for them until there is a problem. The problem takes awhile to surface, and by then everything is coated in oil.
It cost $80 CND for both isolating wires, and installation takes 10 mins.
2x 271-051-01-77 - Cam sensor
The problem with the TSB is that it only references certain engine builds. Mine is 740 and the TSB only referenced 744 (or vice versa, I forget), yet ALL M271 use the same cam sensor, I had the parts department check other VINs to see if there was an updated part #.
So ALL M271 will eventually see this failure.
Please, if you're keeping your vehicle get these wires and install them. If you're under warranty they will not pay for them until there is a problem. The problem takes awhile to surface, and by then everything is coated in oil.
It cost $80 CND for both isolating wires, and installation takes 10 mins.
Thread Starter
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From: BC, Canada
2003 C230K Coupe Orion Blue
Okay, so here's a pic of my engine with the 2 covers off. Pic 1 shows the front of the engine. I assume the ECU plug cover is the one that is circled in red (you need to pull a handle to unlatch it, and there is a large "F" on top) and the cam sensors are the 2 things with blue/purple arrows. If this is incorrect, someone please correct me.
The ECU plug (ie other end of the cable) was perfectly clean, just as the SA said. However, it looks like nothing was added to the wiring itself. (See pic 2)
My bill said this:
2 271-051-01-77 Magnet
2 002-997-24-90 Cable Tie
2 271-051-00-32 Cover
The ECU plug (ie other end of the cable) was perfectly clean, just as the SA said. However, it looks like nothing was added to the wiring itself. (See pic 2)
My bill said this:
2 271-051-01-77 Magnet
2 002-997-24-90 Cable Tie
2 271-051-00-32 Cover
Last edited by slammer111; Jan 15, 2008 at 12:26 AM.
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Mercedes
That's good the ECU is clean, yet was it before you brought the car in? They probably cleaned it.
Looks like neither the isolating cable were installed nor the engine harness replaced.
I'd ask them to:
1. Check the O2 sensor connectors.
2. if there is any oil in those connectors, demand the engine harness and O2 sensors be replaced. Otherwise this is just a problem you'll encounter later on as the rest of the oil works its way out of the harness and ruins the sender in the O2 sensor connectors.
3. The isolating cable was probably not installed cause your engine build # does not match the TSB. Demand that they are, especially since the cam sensors are the exact same part # of the ones that leak, and will leak again.
Your Service manager will complain that he cannot install parts that do not match the TSB. That's when you get him to call the district manager and complain yourself, that its unacceptable to fix a part with the same part known to fail.
You're going to have to get confrontational for this to happen, they will not offer this fix themselves. MB has gotten very cheap, hoping to pass these failures along to the customer after warranty expires.
Good luck.
Looks like neither the isolating cable were installed nor the engine harness replaced.
I'd ask them to:
1. Check the O2 sensor connectors.
2. if there is any oil in those connectors, demand the engine harness and O2 sensors be replaced. Otherwise this is just a problem you'll encounter later on as the rest of the oil works its way out of the harness and ruins the sender in the O2 sensor connectors.
3. The isolating cable was probably not installed cause your engine build # does not match the TSB. Demand that they are, especially since the cam sensors are the exact same part # of the ones that leak, and will leak again.
Your Service manager will complain that he cannot install parts that do not match the TSB. That's when you get him to call the district manager and complain yourself, that its unacceptable to fix a part with the same part known to fail.
You're going to have to get confrontational for this to happen, they will not offer this fix themselves. MB has gotten very cheap, hoping to pass these failures along to the customer after warranty expires.
Good luck.
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Mercedes
The connectors for the O2 sensors are under the car.
Read this:
https://mbworld.org/forums/c-class-w203/206488-diy-m271-o2-sensor-replacement.html
This is why the majority of the oil that gets into the harness leaks into the O2 sensor connectors. Gravity is a wonderful thing, probably all that saves the ECU from becoming drenched.
Read this:
https://mbworld.org/forums/c-class-w203/206488-diy-m271-o2-sensor-replacement.html
This is why the majority of the oil that gets into the harness leaks into the O2 sensor connectors. Gravity is a wonderful thing, probably all that saves the ECU from becoming drenched.
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From: Laguna Niguel, CA
At about how many miles does this typically happen? I was hoping I can squeeze a few more months out after the warranty expires in June.
Just thought of something, can someone post a picture of what the cam sensors look like when leaking. Then we all can squirt a drop of oil in the right spot and bring it in while under warranty and say that they are leaking. The new ones won't leak, right? Don't need the harness unless it already leaked.
Just thought of something, can someone post a picture of what the cam sensors look like when leaking. Then we all can squirt a drop of oil in the right spot and bring it in while under warranty and say that they are leaking. The new ones won't leak, right? Don't need the harness unless it already leaked.
Last edited by Buellwinkle; Jan 15, 2008 at 03:56 PM.
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Mercedes
Want it replaced under warranty? Squirt oil into the connector.
Want everything replaced? Squirt oil into the MAF, O2 sensors, ECU, crank sensor, ... enough so that it all fails.
I do not condone this.
This is why slammer/Ed should be mad. They replaced the cam sensors only to have them leak again in 4 years. The isolating cable doesn't prevent a leak, it only prevents it from leaking into the engine harness. Instead next time it'll leak down the front of the engine and onto the belts!
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Thread Starter
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Joined: Dec 2003
Posts: 3,275
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From: BC, Canada
2003 C230K Coupe Orion Blue
Update
Okay, so I called my SA. He said the tech did everything "by the book" and sure enough, my "build" of M271 was not on the list, which would explain why only the sensors were replaced. Apparently the exact cam sensors (listed under different part #) are also used on the M111, and they have the exact same fix! And yes, he agreed that ALL M271s and M111s will eventually suffer this fate.
The SA did say that they've updated part suppliers and that he hasn't seen them leak since (of course not, you just replaced them all this year
) I told him that's fine, but then if he's not going to put them in, I want it on paper that he's guaranteeing they won't. He called back and said if they were put in along with checking the harness, then it would be covered under warranty (ie it's too late for me since I already had it done); however, out of "goodwill" he'll try to get management to approve the special repair.
So if you are to have them look/diagnose the problem, do NOT walk out of the dealer without having them installed!
Whatever works, I just want to make sure this problem goes away. SA said he'll call me first thing tomorrow.
The SA did say that they've updated part suppliers and that he hasn't seen them leak since (of course not, you just replaced them all this year
) I told him that's fine, but then if he's not going to put them in, I want it on paper that he's guaranteeing they won't. He called back and said if they were put in along with checking the harness, then it would be covered under warranty (ie it's too late for me since I already had it done); however, out of "goodwill" he'll try to get management to approve the special repair.So if you are to have them look/diagnose the problem, do NOT walk out of the dealer without having them installed!
Whatever works, I just want to make sure this problem goes away. SA said he'll call me first thing tomorrow.
Last edited by slammer111; Jan 16, 2008 at 04:30 AM.
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So MB knows there's a serious problem, but will not fix it under warranty if it hasn't happened yet but it will likely go very soon after warranty, certainly something to complaint to NHSTA about to campaign for a recall. Also, it makes sense for everyone that is close to the end of their warranty to put a drop of oil on their connectors, get the CEL on and then bring it in and have the work done, at least you would get 4 more years out of the car.
Certainly the least we should all do under our last days of warranty is check for oil in the connectors, if it's there, run the motor with cam sensors diconnected so it throws a code, then plug it back and bring it to the dealer for repair.
Certainly the least we should all do under our last days of warranty is check for oil in the connectors, if it's there, run the motor with cam sensors diconnected so it throws a code, then plug it back and bring it to the dealer for repair.
Last edited by Buellwinkle; Jan 16, 2008 at 11:47 AM.
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The cam sensor has not changed part numbers, so I wonder why MB only put certain build numbers on the TSB when ALL builds will be affected.
I know dealers are restricted to following the TSB, they cannot bill for the isolating cables unless the build number matches the TSB. Yet they cannot be foolish enough not to know the problem will resurface after the warranty expires, potentially creating a very bad costumer relationship for the future.
When the SM first told me what the fix was, I immediately asked "has the part been updated? will it leak again?" only to have him respond the fix is to replace with the exact same part. Great, all those cars that have been fixed will leak again. Beware the C-class on the used market.
Good job MB!
I know dealers are restricted to following the TSB, they cannot bill for the isolating cables unless the build number matches the TSB. Yet they cannot be foolish enough not to know the problem will resurface after the warranty expires, potentially creating a very bad costumer relationship for the future.
When the SM first told me what the fix was, I immediately asked "has the part been updated? will it leak again?" only to have him respond the fix is to replace with the exact same part. Great, all those cars that have been fixed will leak again. Beware the C-class on the used market.
Good job MB!
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Mercedes
MB will fix it if you find oil in the connectors, yet most will not know to check it, and the only way to discover the leak is either:
1. CEL due to secondary O2 sensor
2. Oil consumption (indicating a leak)
I'd recommend to anyone that gets the "oil level low" message to check the cam sensors, that's where the leak is.
1. CEL due to secondary O2 sensor
2. Oil consumption (indicating a leak)
I'd recommend to anyone that gets the "oil level low" message to check the cam sensors, that's where the leak is.
Thread Starter
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From: BC, Canada
2003 C230K Coupe Orion Blue
Isolation wires added
Okay, just made a trip back to the dealer. SA put it in for me, free of charge. 2-minute job.
2 271-150-27-33 Starter Line
The lines look like they were kinda designed last-minute by MB (or their supplier). Just a 15cm extension, with a loose rubber sheath over the wires that is slightly shorter than the plugs (ie it can slide around), probably to catch some oil.
Yup, he just popped the hood, folded the new lines in half, tucked them in, and zip-tied them. This can easily be DIYed, just be sure not to let the additional wiring touch the belts, it gets awfully close!
See pics for closeups.
2 271-150-27-33 Starter Line
The lines look like they were kinda designed last-minute by MB (or their supplier). Just a 15cm extension, with a loose rubber sheath over the wires that is slightly shorter than the plugs (ie it can slide around), probably to catch some oil.
Yup, he just popped the hood, folded the new lines in half, tucked them in, and zip-tied them. This can easily be DIYed, just be sure not to let the additional wiring touch the belts, it gets awfully close!
See pics for closeups.
Last edited by slammer111; Jan 16, 2008 at 06:00 PM.
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2005 C-230 Sport Sedan
leaking cam adjusters
i had the parts for a few weeks now, found the time to do it today, was on my 2004 C230 that is out of warranty, was some very minor oil seepage there. i am going to inspect the connectors on my 2005 C230 that is still under warranty tonight, i bought two sets of cables and 4 tie straps, here are a few pictures. the way i attached mine a little different than shown above, they clear the plastic cover just fine and are far from the Belt.
Last edited by carson357; Jan 17, 2008 at 07:26 PM.
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2002 C230 Komp. Coupe
This is a great post. And this is My first post. I have a 2002 C230 Komp. 2 dr Coupe. Out of Warranty.
I just got my car back from the Stealer.
They told me my hole engine harness had to be replaced. They were going to charge me 2000 for the work. I told him forget it. On my service paper it says "camshaft magnet leaking pushing oil through engine harness" Im going to do the work myself.
To see if I get this right.
I need to buy the extension p# A271-150-27-33
Buy Cam sensor
Connect and zip tie them up. What do I do to reset the check engine light?
When it says camshaft magnet, do they just mean cam sensor?
Thanks for the help.
I just got my car back from the Stealer.
They told me my hole engine harness had to be replaced. They were going to charge me 2000 for the work. I told him forget it. On my service paper it says "camshaft magnet leaking pushing oil through engine harness" Im going to do the work myself.
To see if I get this right.
I need to buy the extension p# A271-150-27-33
Buy Cam sensor
Connect and zip tie them up. What do I do to reset the check engine light?
When it says camshaft magnet, do they just mean cam sensor?
Thanks for the help.
Thread Starter
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Joined: Dec 2003
Posts: 3,275
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From: BC, Canada
2003 C230K Coupe Orion Blue
If you're the DIY-type (and have the right reverse-torx socket) you may be able to switch out the cam sensors as well. If you look at the thing, there are only 3 bolts holding the cover on. Might as well replace 'em if you're down there.
Be sure to buy TWO of the extension pieces, one per side
Check Engine Light - either the dealer or someone with the StarDiag computer can do that for you.
Camshaft magnet = cam sensor.
Welcome to MBW
Be sure to buy TWO of the extension pieces, one per side
Check Engine Light - either the dealer or someone with the StarDiag computer can do that for you.
Camshaft magnet = cam sensor.
Welcome to MBW
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From: Laguna Niguel, CA
But if your harness has oil in it you probably have to replace it also, hence the big expense of putting in a whole new engine wiring harness, otherwise the problems will continue. The extension is to keep new oil from dripping into the harness. One advantage of having the dealer do it is that if there is a recall they will have to re-imburse you. This is why it's key to go to the nhtsa website and file a complaint and also, since this messess up sensors, go to the FTC, I believe they handle complaints related to the Federal Clean Air act for motor vehicles.
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From: Charlotte, NC
2013 S550, CLS500, ‘03 SL500, “92 190E Sportline
$12 Hose Issue
I had the $12 vacuum hose leak issue. We fixed it. The CEL is still on. Does the CEL go off after a while? Or does the dealer/a mechanic have to do it?
I wonder if the CEL is on because of the cam sensor issue. I gotta get in there and check.
Glad to have this thread on MBW.
I wonder if the CEL is on because of the cam sensor issue. I gotta get in there and check.
Glad to have this thread on MBW.
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From: Redding, California
AMG GTS
Hi everyone...just wanted to double check on something. (I'm about to deal with the PCV hose issue and this cam sensor problem)
Tonight I popped open the hood and unplugged the cam sensors to take a look and miraculously I did not find one drop of oil! 2003 with about 50,000 miles and not a drop. Thank goodness. But my question is...if I don't have any oil in the cam sensor do I still need to buy a replacement (since the replacement is the same exact part with the same exact fault) or can I just buy the extension lines?
Tonight I popped open the hood and unplugged the cam sensors to take a look and miraculously I did not find one drop of oil! 2003 with about 50,000 miles and not a drop. Thank goodness. But my question is...if I don't have any oil in the cam sensor do I still need to buy a replacement (since the replacement is the same exact part with the same exact fault) or can I just buy the extension lines?
Thread Starter
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From: BC, Canada
2003 C230K Coupe Orion Blue
Extensions alone are good enough. My SA mentioned the sensors are new and "shouldn't" leak but personally I'm iffy on that (shouldn't they have updated part #s? 
) Only time will tell.
) Only time will tell.
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My car is at the dealership, again, and i have the leaking cam problem. The SA called me and said it would be 3700 dollars to fix. Am i screwed? if i add in those parts you guys are talking about, will that fix it? Please help 
Last edited by tozfeekum; Mar 17, 2008 at 01:27 PM.
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C230 Sport Coup + 2006 W164 ML350 + 99 Ford Escort RIP
Dude, you have a different engine, and different issue.
This is a great post. And this is My first post. I have a 2002 C230 Komp. 2 dr Coupe. Out of Warranty.
I just got my car back from the Stealer.
They told me my hole engine harness had to be replaced. They were going to charge me 2000 for the work. I told him forget it. On my service paper it says "camshaft magnet leaking pushing oil through engine harness" Im going to do the work myself.
To see if I get this right.
I need to buy the extension p# A271-150-27-33
Buy Cam sensor
Connect and zip tie them up. What do I do to reset the check engine light?
When it says camshaft magnet, do they just mean cam sensor?
Thanks for the help.
I just got my car back from the Stealer.
They told me my hole engine harness had to be replaced. They were going to charge me 2000 for the work. I told him forget it. On my service paper it says "camshaft magnet leaking pushing oil through engine harness" Im going to do the work myself.
To see if I get this right.
I need to buy the extension p# A271-150-27-33
Buy Cam sensor
Connect and zip tie them up. What do I do to reset the check engine light?
When it says camshaft magnet, do they just mean cam sensor?
Thanks for the help.
