not resolved by replacing all the spark plus,suppressor plugs, cable sleeves, cable p

[Dave Chaucer]

I had my Mercedes c200 taken to a main Mercedes dealer because the car (which has done 98000) was not running well.

The main dealer said that they carried out a diagnostic test which revealed that the car was not firing properly. According to their technician the problem would be resolved by replacing all the spark plus,suppressor plugs, cable sleeves, cable plugs,ignition cables and ignition coils. At a cost of £719.
They telephoned me on Friday to say that they had carried out all this work and the car was not firing on cylinders two and three.

My question is as the problem was clearly not with all the parts they have replaced, why did their diagnostic test say that this was the cause of the problem? Also would you have any idea what the problem might be.

Many Thanks

 

[luders79]

Hello,

Could i just ask what age of c class you have!!

Lee

 

[Dave Chaucer]

C200 auto 1995.

Regards

 

[luders79]

That was quick!

Am i right its an 'm' reg! Did they give you any of the codes that were stored!! Might be a long shot but do you know if the car has an airflow sensor? As this will tell us what engine management system it has?

Lee

 

[Dave Chaucer]

Yes it is an "m" reg. They didn't give me any the codes that were stored and unfortunately I do not know if the car has an airflow sensor.

Regards

Dave

 

[luders79]

O.k not to worry, it sounds to me that you may have the earlier engine management sytem which is know as pec i think or somethink like that! These age of car I know can suffer from the main ecu shutting down two of the cylinders as it doesn't allow the ignition coil to reach the voltage requires to create a spark! These are very expensive sorry to say but you can get second hand ones from the big second hand merc breakers. It may be worth asked you dealer to check this the ecu is located under a cover under the screenwash bottle on the n/s inner wing.

Hope this is of some help

Lee

 

[Dave Chaucer]

Thanks very much. Do you have any idea what these parts cost new & second hand.

Regards

Dave

 

[luders79]

If you've got the system i'm talking about and thats the problem which you will have to get checked don't just take my word for it!! But I think the last one I did was about £1200-1300 + vat brand new and I got a second hand one for £500 from mercman in southhampton!

Good luck Lets us know how you get on!!

Hope i've managed to help you out abit

Lee

 

[Classic C200]

I had my Mercedes c200 taken to a main Mercedes dealer because the car (which has done 98000) was not running well.

The main dealer said that they carried out a diagnostic test which revealed that the car was not firing properly. According to their technician the problem would be resolved by replacing all the spark plus,suppressor plugs, cable sleeves, cable plugs,ignition cables and ignition coils. At a cost of £719.
They telephoned me on Friday to say that they had carried out all this work and the car was not firing on cylinders two and three.

My question is as the problem was clearly not with all the parts they have replaced, why did their diagnostic test say that this was the cause of the problem? Also would you have any idea what the problem might be.

Many Thanks

Simple Solution

Take it back to The Main Dealers who said "The problem would be resolved" by replacing the said parts and ask them to explain why the problem is not resolved.

Don't fiddle with it or do anything until you have an explaination from them and a refund of your £719.00!

 

[luders79]

Simple Solution

Take it back to The Main Dealers who said "The problem would be resolved" by replacing the said parts and ask them to explain why the problem is not resolved.

Don't fiddle with it or do anything until you have an explaination from them and a refund of your £719.00!

As classic c200 said above this should be your first option. My advice was if they couldn't solve it! Wasn't suggesting that you don't demand your money back or get an explaination they have to do something!!!

Lee

 

[Dave Chaucer]

Thank you for your help and advice. I will update you on the outcome.

Regards

Dave

 

[Classic C200]

Hope you get on OK Dave........

If, as Lee suggests the ECU is at fault I am surprised that with all the thousands of pounds of diagnostic equipment Main Dealers have, that they could not see that. Even if it is a Fuel injection fault, that would show on the diagnostics.

The main words you have to keep saying to yourself is that they said "The problem would be resolved" after spending £719.00

If they now say the ECU is at fault and you need a new one then thats their problem!

Don't let them walk all over you!

Do let us know the outcome!

It might help others!

 

[Dave Chaucer]

Ian was spot on with his diagnosis. The main dealer telephoned me to say, that the technician had spent 7.6 hours conducting manual tests before he reached the correct diagnosis, which was the ECU.

He said that the ECU is difficult to access and the only way to diagnosis the problem was by spending 7.6 hours working manually on the car (he did ititally say 9.2 hours). I quoted from my Hayes manual which states "that if a series of tests fail to reveal the cause of the problem take the vehicle to a Mercedes dealer who will use a special test instrument to locate the fault quickly and simply (emphasis on quick & simple), alleviating the need to test all the system components individually which is a time consuming operation that carries a high risk of damaging the ECU (emphasis on damage)". He was very quick to say that they had not damaged the ECU. He also said that the coils had damaged the ECU. I asked how did he know that this was the cause of the damage and his response was that he did not know.
He said that that the ECU could only be tested manually and the special test instrument does not test the ECU.

Regards

Dave