How many C coupes are still here?
06-20-2024, 11:52 AM
#76
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C230K Sportcoupe 2002 (early M271)
Greetings
Another year at most and it's definitely getting a rebuild. It's discernible when listening but could be worse
Regarding your noise on load, after I changed the front lambda I got a rough, clunky engine noise under load 2000-3000 rpm which is independent from the engine revs (M111), only on warm engine . No idea whatsoever.
Do I have a chance to diagnose it without STAR? Spark plugs looks more lean since the Lambda change. It was a nightmare to get the Lambda out, totally seized.
I'm not an expert! However, if the front lambda was nasty, sounds like you might now be experiencing the same issue.
The other lambda isn't expensive (got a Bosch for well under 100eur) so I would definitely replace that too first, and see if it helps.
Could also get a reading with a regular OBD tester and check for codes. A code indicating running lean (or something similar) would point to the same issue - a wacky sensor causing overfeeding of fuel, which cat then has to burn, putting it at risk.
Forgot to mention but since I was running rich, fuel efficiency was horrid. If it's up in comparison to your baseline by some liters per 100km, another clear sign.
Good luck, let us know how it goes!
Another year at most and it's definitely getting a rebuild. It's discernible when listening but could be worse
Regarding your noise on load, after I changed the front lambda I got a rough, clunky engine noise under load 2000-3000 rpm which is independent from the engine revs (M111), only on warm engine . No idea whatsoever.
Do I have a chance to diagnose it without STAR? Spark plugs looks more lean since the Lambda change. It was a nightmare to get the Lambda out, totally seized.
The other lambda isn't expensive (got a Bosch for well under 100eur) so I would definitely replace that too first, and see if it helps.
Could also get a reading with a regular OBD tester and check for codes. A code indicating running lean (or something similar) would point to the same issue - a wacky sensor causing overfeeding of fuel, which cat then has to burn, putting it at risk.
Forgot to mention but since I was running rich, fuel efficiency was horrid. If it's up in comparison to your baseline by some liters per 100km, another clear sign.
Good luck, let us know how it goes!
06-21-2024, 02:17 AM
#77
MBWorld Fanatic!
Thread Starter
Listening to SC with a screwdriver, those vanes thrashing around inside do make a racket, but I
don't think thats abnomal. I thought mine had siezed. Actually it was the alternator.
I found one online with 79K original miles off an SLK for $250 delivered (it was a yard and they posted a pic of the
Odo) before I knew it was the alternator. So I replaced it anyway with new oil, kept the old (2nd one)
as a spare along with the alternator. Much easier to access alternator with SC out of the way anyway.
I never had any problems with the 02 sensors, since I just replaced them as suggested by Mercedes at 100K miles.
don't think thats abnomal. I thought mine had siezed. Actually it was the alternator.
I found one online with 79K original miles off an SLK for $250 delivered (it was a yard and they posted a pic of the
Odo) before I knew it was the alternator. So I replaced it anyway with new oil, kept the old (2nd one)
as a spare along with the alternator. Much easier to access alternator with SC out of the way anyway.
I never had any problems with the 02 sensors, since I just replaced them as suggested by Mercedes at 100K miles.
Last edited by C230 Sport Coup; 06-21-2024 at 02:22 AM.
06-21-2024, 10:28 AM
#80
Still think this is the best system in the car industries. The placement is in the right spot where you have to look at. The information is enough and no TMI. It gets activated when you drive slow and has a side sensor to protect your mirror.
In the vid you can hear the play in the coupler if you wiggle the supercharger pulley with your hand. You can get new ones from ebay 10-20$.
In the vid you can hear the play in the coupler if you wiggle the supercharger pulley with your hand. You can get new ones from ebay 10-20$.
Last edited by 112233; 06-21-2024 at 10:41 AM.
06-21-2024, 10:31 AM
#81
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Join Date: Apr 2024
Location: Helsinki, Finland
Posts: 7
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C230K Sportcoupe 2002 (early M271)
Listening to SC with a screwdriver, those vanes thrashing around inside do make a racket, but I
don't think thats abnomal. I thought mine had siezed. Actually it was the alternator.
I found one online with 79K original miles off an SLK for $250 delivered (it was a yard and they posted a pic of the
Odo) before I knew it was the alternator. So I replaced it anyway with new oil, kept the old (2nd one)
as a spare along with the alternator. Much easier to access alternator with SC out of the way anyway.
don't think thats abnomal. I thought mine had siezed. Actually it was the alternator.
I found one online with 79K original miles off an SLK for $250 delivered (it was a yard and they posted a pic of the
Odo) before I knew it was the alternator. So I replaced it anyway with new oil, kept the old (2nd one)
as a spare along with the alternator. Much easier to access alternator with SC out of the way anyway.
I recall reading that a bad A/C compressor can also make some similar noises, but don't quote me on that
Last edited by CL203 from HEL; 06-21-2024 at 11:53 AM. Reason: more replies
