Fuel Injector Problem.

[sammmo]

One of the fuel injectors in my Mercedes ml350 became faulty.. so I’ve had a new one fitted and all seems ok. I’m now worried that the other injectors could start to fail. Should I get rid of the car? Or is there a good cleaning additive I can start using to maintain the reliability of my car.

[Hymie]

You don’t say how old the vehicle is, or its approximate value.

Fuel injectors typically last around 100,000 miles – so if the vehicle mileage is around this value, you can expect other injector failures in the near future.

Being Mercedes, the parts are likely to be over priced, and if you use a main-dealer even more so, with their service charges.

What with it being a 6 cylinder engine, replacing all could be quite expensive.

Personally, I’d see what a non-main dealer would charge to replace an injector, multiply this by 5 and compare it to the value of the vehicle before deciding whether to sell.

[bhg481]

I've had fuel injected cars since 1985, 3 petrol and 2 diesel. On all of them I have put a bottle of injector cleaner in with the fuel once or twice a year (5-10,000 miles); I suspect you get the same effect by using premium fuel. Only one car has given me a problem when 12 years, 200,000 miles old which was cured by cleaning up the electrical connections. Fuel consumption on all the cars has been consistent all the time I've owned them. I've always argued that the injector cleaner might be a gimmick but, at about a fiver a go twice a year, it's not an expensive gamble.

[Hymie]

A Renault Ms Hymie owned, had an ‘injector failure’ that turned out to be a faulty electrical connection – so if the engine is running rough, and the OBD is pointing to an injector fault, check out the electrical connections before an expensive injector replacement.

[sammmo]

The car is 11 yrs old. And only done 70000 miles. But it’s used mostly for short trips. I do use a Mercedes specialist but they are a lot cheaper than Mercedes main dealers. The car is worth around £10000 so I have to get it fixed. I’ve not used any additives in this car so I’m hoping by having just 1 injector fitted and getting it serviced and adding an additive will do the trick.

[Hymie]

Although you’ve had one injector failure at 70,000 miles, to be honest I’d expect you would be unlucky to see further failures more frequently than one every 10,000 miles or so, given that they should last around 100,000 miles.

Given the age/value of the car, potential injector failures would not be a major concern to me – you can be pretty sure something more expensive will require fixing in the not too distant future.

That doom & gloom assessment is no reason to sell and buy a newer car, because your annual depreciation is now probably less than £2,000; whereas on a newer car it could be well over £5,000.