W208 Another Fuel consumption help
Thread Starter
Junior Member
Joined: Apr 2014
Posts: 51
Likes: 0
CLK230 W208
W208 Another Fuel consumption help
My fuel consumption is a bit higher than what it should be. It is a 2001 CLK230 W208 with 125K miles on it.
The car feels a bit rough on idling and the exhaust tip goes black. On highway with 70-80mph cruise control, i get about 18-19mpg and in city about 15mpg. I went to check and it throws O2 sensor so i am in the market.
Its very hard to find MB OEM part where I live but from Bosch O2 sensor catalog (M 111.982) i found that Bosch part numbers are 0 258 006 167 for front and 0 258 006 125 for back.
http://www.bosch.com.au/car_parts/en...r__Cat_WEB.pdf
I managed to find the part but before pulling the trigger. Couple of questions:
1. How many O2 do I need for front and back? front and back are not interchangeable but does left and right identical?
2. Can somebody please confirm the Bosch number above is correct?
3. I not sure if my MAF is also a faulty but I might as well change it. Can somebody confirm if Bosch 028 021 7114 is the right part?
4. I am not sure my spark plug age but would it give me better MPG if I change it along with O2 sensor and MAF at the same time? What spark plug should I be looking?
I am going for another 600miles ride by next weekend so appreciate if anybody can confirm my questions above.
Regards,
The car feels a bit rough on idling and the exhaust tip goes black. On highway with 70-80mph cruise control, i get about 18-19mpg and in city about 15mpg. I went to check and it throws O2 sensor so i am in the market.
Its very hard to find MB OEM part where I live but from Bosch O2 sensor catalog (M 111.982) i found that Bosch part numbers are 0 258 006 167 for front and 0 258 006 125 for back.
http://www.bosch.com.au/car_parts/en...r__Cat_WEB.pdf
I managed to find the part but before pulling the trigger. Couple of questions:
1. How many O2 do I need for front and back? front and back are not interchangeable but does left and right identical?
2. Can somebody please confirm the Bosch number above is correct?
3. I not sure if my MAF is also a faulty but I might as well change it. Can somebody confirm if Bosch 028 021 7114 is the right part?
4. I am not sure my spark plug age but would it give me better MPG if I change it along with O2 sensor and MAF at the same time? What spark plug should I be looking?
I am going for another 600miles ride by next weekend so appreciate if anybody can confirm my questions above.
Regards,
Senior Member
Joined: Sep 2013
Posts: 260
Likes: 0
From: Pittsburgh, PA
W208 CLK55 AMG, W203 C32 AMG, W163 M Class Sport
An alignment and increased tire pressure would help. Slightly over-inflated tires will wear the middle of the tires more but net less rolling resistance. It sounds like everything is on point changing 02 sensors if they throw a code. Spark plugs are also a good idea. I'd wait to change the MAF last if MPG doesn't improve.
Thread Starter
Junior Member
Joined: Apr 2014
Posts: 51
Likes: 0
CLK230 W208
yep, I have made sure the tire has been inflated properly but tires will need to be replaced anyway and will do alignment along.
Most importantly is the O2 sensor front left and right are identical? MB part number differentiate front left and right as well as rear right and left sensor.
I dig around and come accross this information (just select exhaust gas system). Bosch differentiate front sensor by LHD & RHD?!?! Can somebody please confirm I got the Bosch part number right?
Most importantly is the O2 sensor front left and right are identical? MB part number differentiate front left and right as well as rear right and left sensor.
I dig around and come accross this information (just select exhaust gas system). Bosch differentiate front sensor by LHD & RHD?!?! Can somebody please confirm I got the Bosch part number right?
Thread Starter
Junior Member
Joined: Apr 2014
Posts: 51
Likes: 0
CLK230 W208
Thanks, Just ordered my O2 sensor for front and back. Since its CLK230 4 Cyl. I only have 1 front and 1 rear sensor. Will also do air filter, MAF, and spark plug check this week. Hopefully MPG is back normal. Will report back.
While the car has slight rough idling (and black soot at exhaust) most likely point to O2 failure, One thing I just notice is that the car rattle a bit more when the gear is put on Drive position even if the car is not moving at all i.e.: at red light. when moving, the seems goes away. The rattle only felt when Gear is in Drive and car is not moving. Any idea what might be the cause?
While the car has slight rough idling (and black soot at exhaust) most likely point to O2 failure, One thing I just notice is that the car rattle a bit more when the gear is put on Drive position even if the car is not moving at all i.e.: at red light. when moving, the seems goes away. The rattle only felt when Gear is in Drive and car is not moving. Any idea what might be the cause?
MBWorld Fanatic!
Joined: Apr 2005
Posts: 3,784
Likes: 84
From: SCV SoCal
2002 CLK430
If the rattle comes from under the car, it could be the catalytic converter. The weld that holds the center substrate in place on U.S. spec CLK's has been known to fail. When that happens the core rattles around and ends up blocking the exhaust, causing a lack of power, poor idle, and lousy fuel economy. A muffler shop can check this in less than 10 minutes.
Thread Starter
Junior Member
Joined: Apr 2014
Posts: 51
Likes: 0
CLK230 W208
Success!!
Replaced front and rear O2 sensor today and MPG is back on 27-28 in town. Will check on highway tomorrow. Very happy with the result. Power and responsiveness also greatly increased!
Cat seems to be okay so I adjusted the heat plate nearby and the rattle significantly reduced. The mechanic also fix wind noise problem caused by window gap at driver side.
As next step, I will replace the engine and transmission mount because the car still rattle a bit and do proper oil change i.e.: engine, transmission, filter.
Also will do a bit of sound proofing around the door and replace front speakers as well!
Cat seems to be okay so I adjusted the heat plate nearby and the rattle significantly reduced. The mechanic also fix wind noise problem caused by window gap at driver side.
As next step, I will replace the engine and transmission mount because the car still rattle a bit and do proper oil change i.e.: engine, transmission, filter.
Also will do a bit of sound proofing around the door and replace front speakers as well!
Trending Topics
Senior Member
Joined: Sep 2013
Posts: 260
Likes: 0
From: Pittsburgh, PA
W208 CLK55 AMG, W203 C32 AMG, W163 M Class Sport
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
Thread Starter
Junior Member
Joined: Apr 2014
Posts: 51
Likes: 0
CLK230 W208
Roll down your window completely, Look underneath your door there will be three rubber plug, take it out and adjust each accordingly with Torx T30. for every half turn, close the door and look if it fits well.
In my case, the mechanic just took out the door panel to check whole thing ...
In my case, the mechanic just took out the door panel to check whole thing ...
Senior Member
Joined: Sep 2013
Posts: 260
Likes: 0
From: Pittsburgh, PA
W208 CLK55 AMG, W203 C32 AMG, W163 M Class Sport
Roll down your window completely, Look underneath your door there will be three rubber plug, take it out and adjust each accordingly with Torx T30. for every half turn, close the door and look if it fits well.
In my case, the mechanic just took out the door panel to check whole thing ...
In my case, the mechanic just took out the door panel to check whole thing ...
Thread Starter
Junior Member
Joined: Apr 2014
Posts: 51
Likes: 0
CLK230 W208
While running at highway now fixed 31-32mpg @80mph cruise. I still have problem with rough idling, tachometer seems "hunting" and city MPG still bad (@19MPG).
I am going check for vacuum leak, clean up MAF, Throttle body and EGR check tomorrow hopefully something positive comes out of it.
I am going check for vacuum leak, clean up MAF, Throttle body and EGR check tomorrow hopefully something positive comes out of it.
