Pinging/Knocking/Detonation? Sounds like rocks in the engine on acceleration..
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2017 C300 Coupe (C205)
Pinging/Knocking/Detonation? Sounds like rocks in the engine on acceleration..
So my wife has a 2017 C300 Coupe with the 2.0L Turbo motor. Lately she's been complaining about intermittent knocking/pinging sound that happens when she does a moderately aggressive acceleration (like getting on the freeway or passing someone, about 3/4 throttle). I drove her car the last week and tried and tried to get it to do it and was only successful once.
It basically sounds like engine knocking to me. You get on the accelerator and it immediately starts to sound like rocks are flinging around in the motor. As soon as you let off on the gas, and get back on it the sound goes away. Has anyone else had this problem?
Couple of notes: Car is a 2017 C300 Coupe, 2.0L Turbo motor, about 4500 miles. Uses 91 Octane gas (highest available in Tucson, AZ). Tucson elevation is ~2400 ft above sea level. Outside temps around the 80 degree F range. Car is in "Comfort" mode when it happens.
It basically sounds like engine knocking to me. You get on the accelerator and it immediately starts to sound like rocks are flinging around in the motor. As soon as you let off on the gas, and get back on it the sound goes away. Has anyone else had this problem?
Couple of notes: Car is a 2017 C300 Coupe, 2.0L Turbo motor, about 4500 miles. Uses 91 Octane gas (highest available in Tucson, AZ). Tucson elevation is ~2400 ft above sea level. Outside temps around the 80 degree F range. Car is in "Comfort" mode when it happens.
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2017 C300 Coupe (C205)
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Member
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2017 C300 Coupe (C205)
No, car sounds fine when it starts. It doesn't sound like it needs a valve adjustment, if that's what you're referring to. Everything sounds tight and controlled.
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2016 C300 4Matic traded in for a 2022 E450 Coupe
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C350e
Here 95 is standard and you can get 98 optionally.
Less then 95 is very hard to find here. I guess the US built cars are adjusted for a lower octane number. Might be the tuning has been a bit critical or the sensor detecting the pinging is malfunctioning.
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2017 C300 Coupe (C205)
Sorry i missed the octane numbwr. Still that is quite low for European standards.
Here 95 is standard and you can get 98 optionally.
Less then 95 is very hard to find here. I guess the US built cars are adjusted for a lower octane number. Might be the tuning has been a bit critical or the sensor detecting the pinging is malfunctioning.
Here 95 is standard and you can get 98 optionally.
Less then 95 is very hard to find here. I guess the US built cars are adjusted for a lower octane number. Might be the tuning has been a bit critical or the sensor detecting the pinging is malfunctioning.
Europeans use the Research Octane Number (RON) standard. US uses the AKI standard which is an average of the RON number and the Motor Octane Number (MON).
For that reason, a RON number will always be 4-6 points higher than the US's AKI number.
As an example:
European 95 RON is about equal to US 91 AKI.
European 98 RON is about equal to US 93 AKI.
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C350e
It's actually the same octane level but the number is calculated differently in each country.
Europeans use the Research Octane Number (RON) standard. US uses the AKI standard which is an average of the RON number and the Motor Octane Number (MON).
For that reason, a RON number will always be 4-6 points higher than the US's AKI number.
As an example:
European 95 RON is about equal to US 91 AKI.
European 98 RON is about equal to US 93 AKI.
Europeans use the Research Octane Number (RON) standard. US uses the AKI standard which is an average of the RON number and the Motor Octane Number (MON).
For that reason, a RON number will always be 4-6 points higher than the US's AKI number.
As an example:
European 95 RON is about equal to US 91 AKI.
European 98 RON is about equal to US 93 AKI.
As mentioned also, this looks like a defect then.
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CLS
Gosh, I'm sorry. The problem is the engine. It simply can't be made fully smooth.
There are many inherent design limitations which can only be mitigated or concealed. http://www.nytimes.com/2010/08/15/au...es/15FOUR.html
http://wikicars.org/en/Straight-4_engine
You can't make chicken salad out of chicken ....
There are many inherent design limitations which can only be mitigated or concealed. http://www.nytimes.com/2010/08/15/au...es/15FOUR.html
http://wikicars.org/en/Straight-4_engine
You can't make chicken salad out of chicken ....
Last edited by removedCFGaccount; May 24, 2017 at 07:04 PM.
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2018 C350Te Wagon
Once upon a midnight dreary, while I pondered, weak and weary,
Over many a quaint and curious volume of forgotten lore—
While I nodded, nearly napping, suddenly there came a tapping,
As of some one gently rapping, rapping at my chamber door.
“’Tis some visitor,” I muttered, “tapping at my chamber door—
Only this and nothing more.”
Turns out to be a wheezing four cylinder crap pile....
You can't make chicken salad out of chicken ....
Over many a quaint and curious volume of forgotten lore—
While I nodded, nearly napping, suddenly there came a tapping,
As of some one gently rapping, rapping at my chamber door.
“’Tis some visitor,” I muttered, “tapping at my chamber door—
Only this and nothing more.”
Turns out to be a wheezing four cylinder crap pile....
You can't make chicken salad out of chicken ....
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CLS
Diversity makes the world go. I had my last one years ago. Your mileage may vary, as will the commentators' opinions. The laws of physics don't have feelings.
Last edited by removedCFGaccount; May 24, 2017 at 09:18 PM.
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2017 C300 Coupe (C205)
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C450, GLC43
That's completely true, it will be rougher than a 6 or an 8. It shouldn't ping or knock though. I just drove a C300 loaner 2 weeks ago while my 450 was in for service A and a tire swap. The C300 did sound like a 4 banger for sure, but there was nothing in the engine note that resembled knocking or pinging at all. It just sounded like a high-strung turbo 4.
Happa, either you or your wife accidentally got a tank full of 88 or you have an engine problem. If I knew for sure that the fuel was good, I wouldn't hesitate to take it in and request that the tech ride with you while you demo the noise for him.
Happa, either you or your wife accidentally got a tank full of 88 or you have an engine problem. If I knew for sure that the fuel was good, I wouldn't hesitate to take it in and request that the tech ride with you while you demo the noise for him.
Last edited by Mr. J; May 25, 2017 at 12:55 AM.
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c250 w205
I have the same problems.. it only happens in the morning first hard acceleration.. problems solved after i change fuel.. i usually use Shell 95.. and change to Pertamina 98 or Total 95 ( thats the fuel brand in my country )
i m drivin w205 c250 2015..
definitly about the quality from the fuel.. strange knockin happen only at first hard acceleration..
i m drivin w205 c250 2015..
definitly about the quality from the fuel.. strange knockin happen only at first hard acceleration..
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Car free at the moment
I have head this sound in loaner c300 sedans when getting my car serviced. It's normal noise for a direct injected engine. Kinda sounded like the engine was munching gravel when overtaking. DI gasoline engines all sound a little bit like an old diesel. It's the trade off for the extra efficiency of using direct injection. I have a Ford with their 2.0 turbo DI engine. It's a bit more diesel sounding at idle and quieter in the midrange, but makes similar sounds as the MB motor.
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2017 C300 Coupe (C205)
I would completely disagree that it is normal noise for direct injection. I have a 2008 Mazdaspeed 3 with a 2.3L Turbo Direct Injection engine with 118,000 miles and it has never made that sound.
Last edited by Hapa88; May 25, 2017 at 10:45 AM.
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2017 C300 Coupe (C205)
While I agree it's rougher, it does not explain the intermittent pinging/knocking that causes it to be rougher for a period of less than 2 seconds on hard acceleration. Like I said, it doesn't happen all the time.
Over a 20 minute drive of me constantly hammering it off the line or hard passing, I only experienced it once when I drove it.
I'll quadruple check with her to make sure she's using Premium gas, because that was my initial thought as well.
Over a 20 minute drive of me constantly hammering it off the line or hard passing, I only experienced it once when I drove it.
I'll quadruple check with her to make sure she's using Premium gas, because that was my initial thought as well.
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2016 c450 / 2016 VW Jetta 1.8t / 2006 Wrangler X
Can you take a video so I can hear some audio of the sound? Most modern direct injection engines do have a very constant ticking, like a sewing machine during idle. The ticking is from the high pressure injectors. Your engine is designed to run on premium, but if lower octane is detected, the car's ECU will go into knock protection mode, lowering power output to prevent detonation. If you are experiencing detonation your CEL will go on.
