C270 CDI EML on but diagnostic shows no fault codes

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m19seg

New Member
Joined
Feb 18, 2012
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5
Car
C270 CDI
Hi All,

I am new to the forum. Hoping some of your experties may help me identify my issue.

I have a 2004 C270 CDI. My engine management light (eml) came on a few days ago. I took it down to my local Benz specialist (not MB) and he ran a diagnostic on the the car; diagnostic showed no faults, and the mechanic said it was due to the fact that I was driving the car on low diesel with fuel light on... something about a misfire whilst low on diesel? He turned the light off and said it should be fine.

The light came back on the next time I started the car, but with no fault codes appearing I am at a loss and not sure what to do. I am sure if I take it back they can have a look around, make suggestions and change parts but without an obvious fault that could take my garage bill through the roof without resolving the problem.

I have noticed on occasions that the car is making a wheezing noise when I accelerate, when it does this the car feels abit groggy, but this happens every other day and rest of days it sounds fine.

Also I have found that when I put the heating on or the air con on it takes a long time to do both jobs doesnt heat up quick, and doesnt cool quick; also on a couple of occasions when I have put the windscreen heater or the fan on it would be running fine and then suddenly makes a choking noise (kinda like a hoover when you get something big stuck in it) upon which I would quickly turn the air off, when I switch it back on it starts to run fine again.

Somebody suggested it might be an airflow problem, possibly blocked airpipes or something. Has anybody had any similar experiences or know what the problem might be. As mentioned above no fault codes appeared on dianostic machine and the only obvious issue seems to wheezing noise on accelaration.

Thank you in advance for your help. PS as I am new to the forum I dont know if I should be creating new threads? apologies if I have got it wrong.
 
If the EML comes on there will be a fault code recorded.
 
Hi Dieselman, well nothing was mentioned other than the mechanic looking at the screen and asking me whether I have driven on low fuel, I told him yes and he said thats your problem dont do it again.

He turned the light off and said there are no other faults appearing. I will be going to see him again on Monday morning so I can ask him if there was a fault code and if so what it was.

Im assuming he will be seeing the same thing again when I go, will check with him and post his comments for further detail.
 
As DM says if the EML light comes on it will be recorded
 
Thanks Beno,

I will speak to my local garage again and come back with more detail.

In meantime if anybody has come across wheezing issue before I will be interested in knowing your experience either as a car owner or someone who has diagnosed and fixed a similar problem.

Thank you.
 
Is it a wheezing or a whistle? Whistle could indicate a turbo issue (worst case scenario) or an induction leak
 
I would definitely describe it as a wheezing noise. Very faint noise, you have to put the music down and pay attention to hear it. Seems to be coming from the passenger side. It doesnt happen all the time, comes and goes. It might not even be linked to the EML but its the only obvious thing at the moment.
 
Putting it on a star will give you the answer, trying to guess will only take you down expensive blind alleys. Good luck
 
Cheers Beno. Will post on MOnday again if I get any more specific information from the garage.
 

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