2005 C240 Engine rough when cold. Sounds like a truck!
Thread Starter
Super Member
Joined: Jul 2009
Posts: 938
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From: Montreal, Canada
2005 C240 2011 R350
2005 C240 Engine rough when cold. Sounds like a truck!
Hello
Weather getting cooler again and now my 2005 C240 is sounding rough untill warm. Like a truck!
Any ideas? It happened 2 years ago and I brought it to the dealer. they charged me $240 to change the engine mounts under warranty and "retorque" the transmission/exhaust bolts. Made no sense.
I think it is a sensor or other item that operates until warm...Or is not operating properly.
thanks
Weather getting cooler again and now my 2005 C240 is sounding rough untill warm. Like a truck!
Any ideas? It happened 2 years ago and I brought it to the dealer. they charged me $240 to change the engine mounts under warranty and "retorque" the transmission/exhaust bolts. Made no sense.
I think it is a sensor or other item that operates until warm...Or is not operating properly.
thanks
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Joined: Jun 2008
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Clean the MAF. What mileage has the car done? Are O2 sensors in good condition? You might not be getting proper mixture enrichment when cold.
Does the car stumble when you pull away cold?
Does the car stumble when you pull away cold?
Junior Member
Joined: Jun 2011
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2005 Mercedes c230
I think that's a normal thing for a I4 engine. I have an 05 c230 with 38k miles recently serviced B from mercedes. Mine when started sounds pretty loud and very unlike a luxury car. I think that's the drawback of an inline engine. When it warms up it sounds much better.
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2019 G70 6MT & 2022 Ford Maverick XL
The four-cylinders are certainly loud and unflattering, especially given how great the car looks at the same time how not great it sounds.
But I don't hear any hissing noises by my exhaust. Some burbling but no hissing.
But I don't hear any hissing noises by my exhaust. Some burbling but no hissing.
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Joined: Oct 2010
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From: Boston
12 E350 4Matic Sport
Glyn - Can you tell us what it means when the car stumbles when pulling away cold? Happens to me all the time. Is it time to clean the MAF?
Not trying to thread jack, by the way.
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Super Moderator
Joined: Jun 2008
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Possibly clogged Cat or a piece of Cat honeycomb has broken off & is clogging something. Presume no area of the exhaust has been damaged on a speed bump or similar? Might have a hole in a pipe or muffler/silencer.
Last edited by Glyn M Ruck; Oct 31, 2011 at 11:48 AM.
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Super Moderator
Joined: Jun 2008
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Experiencing the same thing...I always assumed it was normal with the cats needing to warm up and all.
Glyn - Can you tell us what it means when the car stumbles when pulling away cold? Happens to me all the time. Is it time to clean the MAF?
Not trying to thread jack, by the way.
Glyn - Can you tell us what it means when the car stumbles when pulling away cold? Happens to me all the time. Is it time to clean the MAF?
Not trying to thread jack, by the way.
It's time to look at the MAF & upstream O2 sensors. Check if the car is storing any codes.
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From: chicago
2005 c230 kompressor 2003 s500 94 wrangler
hahaha i told this to the dealership...they "ran" a leakdown test and found no leaks...
Thread Starter
Super Member
Joined: Jul 2009
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From: Montreal, Canada
2005 C240 2011 R350
thanks
Thread Starter
Super Member
Joined: Jul 2009
Posts: 938
Likes: 53
From: Montreal, Canada
2005 C240 2011 R350
Just checked with my OBDII tool and no codes show up. I am at a loss? should I just go and clean the MAF sensor?
I would have expected bad O2 sensors to throw a code. However my understanding is that the engine runs open loop until the O2 sensors are warm anyway so there should be no change in condition while engine is cold if the O2 sensors are bad.
thanks
I would have expected bad O2 sensors to throw a code. However my understanding is that the engine runs open loop until the O2 sensors are warm anyway so there should be no change in condition while engine is cold if the O2 sensors are bad.
thanks
