Also, it has started to missfire and run extremely roughly, this is corrected when the ignition is turned off and on again, this has only happened twice, service work carried out so far, 16 new platinum plugs fitted, new air cleaner filters, new fuel filter, fuel lines backflushed, could it be the MAF? I have run out of ideas, other than taking it to a MB authorized Dealer at great Expense! No error codes have been logged in the onboard computer at the time of this problem occurring. Would appreciate any advice you can offer? Kind regards, Phil.