I am biting my tongue over the additive issue and 'warranty'
However I am slightly surprised that the warranty has expired because the car is over 3 years old??
I will quote from Mercedes-Benz latest version of MobiloLife page 10
Warranty or Goodwill Repairs
(requiring more than two working hours)
Up to 4 years*
If you visit a Mercedes-Benz Service Centre for a
warranty or
goodwill repair requiring more than two working hours, MobiloLife takes effect. You will find details of the individual services in the table provided.
*MobiloLife is valid for the new vehicle for an initial period of 2 years. Thereafter, MobiloLife is renewed everytime a service is carried out at a Mercedes-Benz Service Centre and is valid until the next service is due. For warranty and goodwill repairs this applies up to a maximum of 4 years
Now taking the head off I would assume would meet the criteria of 'two working hours'. In my experience service centres have been most helpful PROVIDING you have complied with
ALL the requirements of MobiloLife.
It is NOT the Service Centre's money that will pay for the repair, they just have to confirm with Mercedes-Benz that your service book is in order and they 'might' check that you have
NOT put any additives into the fuel.
I must apologise for harping on about this 'hot potato' of additives, no one has to convince me on the rights or wrongs of it. I am merely stating the terms of the warranty. If you put
ANY additive into the fuel then the warranty conditions are 'limited'. It does not say 'some' or 'might be alright'.
It is possible that you might get away with using some of these excellent 'cleaners' and get your claim approved. BUT you cannot complain if the claim is refused on the grounds that you have put any type of additive into your fuel.
I wish you luck with the repair,
Regards,
John