CLK55 Confusion

[rees_A]

I have a CLK55 W208. I have been running on super unleaded for a few weeks which seem to have resolved the loss of power issues etc. The last time I filled up I had to use normal unleaded and the car is underpowered/not quite running as smoothly.

I can't believe that the grade of petrol will make such a huge difference and think my MAF may be faulty. I'm going to put super unleaded in on the next fill to see definitively whether it makes the difference.

My question is, does anyone else use normal unleaded in their 55's and does it run ok...

I have no warning lights etc. Just tried to acelerate and was barelt able to vertake a van earlier today although engine seemed to rev ok to almost red line just didn't go anywhere????

 

[jaymanek]

nahh sounds like a MAF issue. think the fuel thing was just a coincidence.

Im sure the W208 is set up for normal 95 RON.. it will say inside the fuel flap.

 

[x332race]

Could have been detergents in the super cleaning out some "gunk" in the system?

 

[Londonscottish]

as per jaymanek sounds like MAF

 

[rees_A]

I thought it sounds like MAF. I will try super again when current tank empties and will get the MAF replaced. Think I'd better get new air filters at the same time just to be sure

 

[chiefski26]

maf

 

[andy27168]

I thought it sounds like MAF. I will try super again when current tank empties and will get the MAF replaced. Think I'd better get new air filters at the same time just to be sure

Hi,
I think as others that its your MAF playing up very easy to change, takes about 20 minutes or so, and as Jay says the 113 engine is designed to run on 95 RON. (same as a C43).
Be warned though your air filters from MB will be in excess of £85, as I believe you have the same airbox as a C43, though if you drop me a PM I can let you have the FRAM pt. no. for the filters, should save you at least half that I would have thought.

 

[Rob77]

engine seemed to rev ok to almost red line just didn't go anywhere????

I have no doubt everyone is correct but, in my ignorance, I don't see how this is possible. Surely, if the engine is reving correctly, the car must move correctly unless there is an issue with the drivetrain?

Appologies in advance for showing my stupidity

 

[Alps]

maybe it was just a dodgy batch of fuel... if it was MAF then you would feel the differance even with super unleaded!

 

[rees_A]

maybe it was just a dodgy batch of fuel... if it was MAF then you would feel the differance even with super unleaded!

I was wondering that myself as the last few times I've filled with super unleaded and it's been behaving 100% no rough idle, fast when I want it to be, and slightly better mpg... I think I'll use up whats in the tank then re-fill with super and see if it goes back to normal. Don't really want to buy a maf if I don't need one.(Even though I have warranty that covers the cost of replacement, if I take it to garage and they don't find a maf fault it will be difficult to claim for one..)

 

[rees_A]

Update.. my car doesn't run on unleaded. Just put super in again and all is fine. So strange... Will just not use the poor petrol any more LOL

 

[mickl]

sounds strange. When I first got mine, the low fuel light was on and with 200 mile journey to travel back I stopped at the first station I came to and put in some 95ron unleaded. Travelled about 130 miles on that fill with no problems or rough running. Have run it on super unleaded since from 97 to 99ron stuff. As Jay says, it's designed to run on 95ron anyway.

 

[paulrstaylor]

I wonder if it has been re-mapped by a past owner?

 

[Alps]

i know my E55 needs super unleaded, the c36 worked ok on normal unleaded, but was also better on super.

 

[Will]

Doesn't the M113 have knock sensors, so shouldn't it adjust the ignition timing for the different fuel grades?

Will

 

[dvb247]

Interesting, I have a problem with mine, I have a flat spot thro each gear at low revs, it's driving me crazy, will try super unleaded to at least rule it out!

 

[Alps]

dvb247, you shouldnt be using anything but super unleaded in yours!

 

[rees_A]

It runs ok on 95 ron as long as I drive slowly. It's only no good if I want to drive like a loon...Which is all of the time or I would have bought a c200 lol