Hello, new here and am in need of some assistance. I'm a long time BMW enthusiast, but unfortunately new to the MB world. I have a sister in-law who has an '02 C240 with 70kmi on it. I held her hand and ensured that she do regular dealer maintenance up until the 50kmi mark, then suggested she visit a MB indy afterwards for regular/routine maintenance. I was shocked today when she called and stated that a few days ago, her check engine light illuminated and after diagnostics showed some cylinder mis-fires, they let her go on her way before a prolonged diagnosis.

Low and behold, 200mi later the engine stalled multiple times and finally quit on her in Eastern Washington. The family mechanic there (sorry for the lack of details right now as it's late) indicated that three of the cylinders were badly worn/damaged and that either replacement of those or a complete re-build was necessary. Of course I need to speak with the mechanic to get further details, but I'm trying to search and see if the C240 six-pots are prone to premature failure. In all my years of being a car enthusiast, I've never heard of a modern engine having a failure this early in life - especially with routine maintenance faithfully performed. Has anyone else had this happen or is this one of those "one in a million" events that she is experiencing?

 

My gf had had this to her 03 accord about a month ago. with only 36,000miles

her 4 banger, cylinder 1,2,4 misfire,

replaced sparkplugs, on the way to the poconos, car stalled, trembled. bought it to a friend mechanic, cylinder 1 bent, no pressure in cylinder 1, only 1/2 boost in cylinder 2, 4 full boost in cylinder 3.

replaced valves. gaskets, ported and fixed cylinder 1, replaced all wires and sparks (apparently the new sparks were BURNED).


thats what the c240 should be looking at.

sorry to hear abt this, but MBs are seriously not reliable cars in my perspective.

 

in this day and age, I find it very difficult to believe that newer engines cannot last ~ 200kmi with regular synthetic oil changes. I just can't believe it. Even a Honda - shoot especially a Honda which sounds like your gf nad some worn valve guides and possibly dropped a valve or two?

What is this that I'm seeing in the TSB about oil sludge/class action suit also? Other than this, the car has been rock solid to her...

 

I don't beleive it.
Sounds like BS to me.
I'd try another mechanic.

How did he determine this? Did he do a compression and leak down test?
It smells like bs all the way here to Cali. Peee-ewwww!

Take it to the dealer for some diagnosis time.
Not that dealers don't screw up, but I'd almost bet money they won't come back and tell you the whole engine is bad. Baloney!

 

I'm with you on this. When she told me it was back in her home town, I cringed. I'm thinking backyard mechanic with zero diagnostic tools. Hell, it could be something as simple as a CPS for crying out loud. Carbon build-up, bad MAF, etc etc. Clogged cats, almost anything. But to hear three cylinders are bad? I sure as hell hope he didn't open that engine up!

 

You can read the horror stories in these pages over and over...
what was the one I read tonight?
Lets see....oh yeah, guy goes to the dealer, cause the sunroof won't open and close correctly. Dealer does a quick 'reset' which doesn't solve the problem, and the dealer declares the car needs a $1000 repair.
so the owner is his infinite curiousity, decided to remove the fuse to that circuit, and plug it back in again (thereby removing power and rebooting any
associated electronics) and wow, guess what. It's fixed.

I'm sure everyone here would love to help, so please go get yer info straight,
tell us what this so called mechanic did to come with his determination,
and also go find an OBD2 reader, read out the codes and post them.

You can get one for free at Autozone, pay them 180 on your credit card,
and return it for full refund after you return. There way of loaning it to you.

We could all sit and guess, but thats just a waste of time and bandwidth.
Get the IN-FO so we can actually be intelly-gent like.
Coilpacks have a way of going bad around that time frame...
odb will tell you which cylinders misfiring.

 

OBD may tell you all need to know. Get to it.
MAF related? Clean it before replacing with MAF cleaner from the local parts store. Clogged cats? Not likely, not yet. Carbon build up? Also not likely.

"I'm thinking backyard mechanic with zero diagnostic tools. " Agreed, but then still need the IN-FO.

 

Engine stalling and misfires are common on that car, search the forum but it's could be a faulty fuel pump, bad crank position sensor as well as other things. Without the code it's very difficult. Also, what is a "mild rebuild". Did he find compression problems in the cylinder or head? Does the engine make noise like a spun bearing? Keep in mind different people maintain their cars differently. If the car was driven with very low oil levels or taken to a place that used dino oil then there could be damage to the engine.

 

UPDATE:

1) were any diagnostics performed to determine which cylinders were missing? YES
2) pictures of the air filter - HE DOES NOT HAVE THE AIR FILTERS ANY MORE
3) condition of the oil - HE SAID THE OIL WAS FINE
4) how was it determined that several cylinders were damaged? BY LOOKING AT HOW SCRATCHED UP THE INSIDES WERE
Compression leakdown test? WAS DONE
If so, what were the numbers? 95 LBS AND SHOULD BE LIKE 120 LBS
5) was the engine opened up to examine it? YES
If so, please provide pictures and an explanation of the engine damage - ie worn valves, valve guides, valve-piston contact/damage, excessive ring wear, cylinder wall scoring etc...
6) what is the diagnosis, detailed explanation, estimate of cost/parts/labor, and a timeframe
HE SAID LABOR WILL BE ABOUT $1600
WILL NEED TO REPLACE PISTONS
CYLINDERS NEED TO BE "BORED" OUT

 

one piece of bad news (for her). Looks like the last air-filter replacement was ~30kmi ago - still getting the exact date and mileage stamp of it. The mechanic did mention that the air filter was extremely dirt laden and caused excessive scoring of the cylinder walls...this isn't sounding good and could be yet another hard lesson learned with regards to proper maintenance.

She didn't specify she wanted an air-filter replacement and thought that it was part of the deal when she entered for an oil/filter change. Sigh, I wish people would consult me more...what a shame.

 

wow i,ve never heard of a dirty air filter scoring the cylinder walls that quickley , usually the car will starve of air loooong before enough dirt gets in there to do any damadge unless the air filter had a hole in it or wasn't installed properly

 

I realize this as well and it's a very valid point. When I asked about the air-filters, they weren't available. It's upsetting me a bit not knowing the full story nor seeing the car myself. I'll be over there this weekend and will take some detailed high-res pictures of the scoring if any...

I hate to doubt a mechanic, but I'm the type that needs to be in control of the situation. I hope he doesn't tire of my questions, but I simply cannot take anything at face value. I just don't get how an engine can score itself to death at 70kmi. Things just aren't adding up...

 

So he pulled a head off?
And someone authorized this to be done?
I still don't beleive it.

And now that the head is off, he can do all the repairs for 1500?
I definately don't beleive it.
Just a head gasket would cost that much.

Why would only 3 pistons be damaged?

 

she must have allowed him to do that before contacting me. She trusted him as he is a family friend/mechanic. Honestly, if there really is cylinder wall scoring, this latter part may save her quite a bit of money vs the Dealership labor rates which must be close to $100/hr. Things are much different across the mountains and the work will be outsourced. This part is what worries me - the boring and replacement of the cylinders. Further, the $1600 quote was for labor only as far as I know - parts = extra.

I'll find out more details when I can, but I may just need to call him myself.

 

That should worry you because the 'cylinders' cannot be replaced. My understanding is the alloy block is bored then the cylinder walls are coated via metal deposition, there are no separate cylinder sleeves. Do a search on 'oil consumption' and you'll find where MB has inspected inside the cylinder with a boroscope (no need to open up engine) and then offered to share the cost of the engine replacement....probably depending on mileage...with the owner. I'm guessing there are a limited number of engines with a problem that shows up as scored cylinder walls. Normally these engines don't use oil even after 100k miles.

 

Mitch at this point, she may be your sister in law, and you may want to help her but man she's made a mess of things, and then consults you.

Walk away...at a good clip. Any advise you could offer is too late.
The moment she authorized the engine to be disassembled was the moment
she messed up big time, and now she wants you to fix it somehow and make it all better, because now she finally has to consult a man, and admit she's clueless, but only after trying to be so smart.

Like someone said, could have been a known issue by Benz, easily inspected with a boroscope, ie like a fiber optic devices for viewing inside tight spaces. Any chance of mercedes doing anything for free was lost the moment the head came off.
Any moron shoulda known to do that, and not remove the head.
Likely the same moron who's gonna replace 3 pistons, and bore out the engine, and has no MBZ tools or a clue what he's doing.

Any advise you offer will result in the whole farking mess being your fault.
Women who do first and ask later get exactly what they asked for. Sorry if I sound cruel, I just been down this road too many times with women who think they know everything until they've made such a mess no one can solve it. Now the car's in pieces with dumass, and he's just gonna make it worse.
You got 2 choices. Let him continue and see if he has a clue, 3 grand later, and one 1/2 *** 1/2 rebuilt motor repair later, and see if it blows up after 5K miles, or
b. Haul the car outta there in pieces to the dealer...
either option you propose, you lose.

Why? Because if she continues on with dumass and the car blows up, well you shoulda told her !!
If you haul it out of there in pieces to the poor basturd at the mercedes dealer who gets to pick up the pieces, 5 grand later the car will be fine,
and she coulda had it done cheaper by dumass!

You lose.

Run. Don't walk.

Is this family mechanic versed in MBZ?
I have a local MBZ repair guy.
I go there some times and chew the fat with him.
He's a nice older guy, mid to late 50's.
Get a lot of business on older mercedes.
He really is a little lost when it comes to the newer stuff.

Even if your guy has a clue about mercedes, I doubt he's up on the newer stuff.

 

I agree completely and think she should either have it reassembled and towed to a Merc dealership for diagnosis, or leave the head off and still tow to a Merc dealership. I'll suggest the latter for now.

 

UPDATE:

towed to a Mercedes dealership and they replaced the high-resistance platinum plugs with Merc spec plugs (damn they are exp!), plus replaced two spark plug wires. In normal driving (ie light engine load) the car behaves perfectly.

With load however (ie under acceleration) the car misfires in one cylinder only. Further debug by replacing coil pack and injector did not cure the problem. They are wanting to replace that cylinder's valve springs in the event that one or more are cracked, but they are unsure this will cure the problem.

I didn't want my sis-in-law to eat that theoretical fix so they are now calling a Mercedes technician to take a closer look to see what's up with that particular cylinder.

Either way, lesson learned - don't go to a backyard mechanic and re-build your engine just because he thinks it's what it needs. Total bill to date = $300 (damned spark plugs/wires) and is a helluva lot cheaper than an engine rebuild!

 

Glad this worked out for the better, but still, 70,000 miles and the engine is having serious issues? Cmon... my lowly 'american' Jeep has over 230K on it now- doesn't use any oil, always starts, etc.... Pathetic.

Come to think of it, its pathetic that a Mercedes doesn't have a longer warranty- even a GM or Hyundai is 100,000 miles.

 

i have a c coupe ..and my engine light has been on for a good 7 months .. i didnt fix i yet.. car runs fine.... i put about 5000 miles in since lol ..

FINALLY GETTING IT CHECK OUT TOMOLO ..

fk ya....... it stalled on me today or kidna .. i stopped at the light .. then and gased it .. the car wouldt go like it was on neutral .. then i triped ou for a bit .. and restart my car

 

So....the backyard guy did NOT pull the head?
Wierd about misfiring in the one cylinder...
Swap the plugs to another cylinder and see if the problem follows the plugs.
Yeh, I've had new plugs short out.
The MBZ people would probably never think to check that.
Just because a part is new doesn't mean it aint broke.

I wonder if a cooler plug might help?
Cheap solution to try.
Check NGK for the respective iridium plug, try 2 steps cooler.
Cost, about $7. or is there 2 plugs per cyl.?

Glad to hear she's not out 10 grand and you still got your skin.

 

I had same Misfire problems on #1, #6, #3, & #4 cyclinders & Check Engine Light problem.
My fixed was some what simple, but it took me 4 trips until I got a MB mechanic at dealership to make a decent recommendation.

Solutions:
- change all wires set (6 pair) $30/pair = $180
- change all spark plugs (6 pair) $10 x 12 = $120

Optional fixed:
- change coil pack (I changed 2 of mine for $200 each).

Labor is extra depending on where you get this diagnosed & fixed.
If I changed all wires & spark plugs the very first time, then I could save myself lots of lots of labor cost.

So far, no hesitation, and no misfired after changing all spark plugs & wire set.

 

Dangerous....besides, you'd only be chasing a symptom, not a fix.

 

final update on this old issue. The car had to be towed (at the cost of Mercedes) to a larger dealer in Western Washington. Turns out it had bad fuel, and get this...a bad MAF!!! That's it folks. The title to this thread is so incorrect that I'm embarassed! I wish a Mod could rename it to something like - if a backyard mechanic thinks your engine needs replacing, take it to a qualified Merc dealership to get properly diagnosed. And if all else fails, check the MAF!!! That's a bit too long however...

 

Oh my goodness....sorry to hear....so everything is ok now??