Kept Driving With Petrol in a Diesel Mercedes C-Class?
Keeping the motor off is what matters after you have driven on petrol in a diesel Mercedes C-Class, so pull in as soon as it's safe and then switch the motor off. We can still deal with it where you've pulled up, and if it's caught soon, permanent damage is very rare.
Your Mercedes C-Class can stay wherever it has stopped, because Petrol in Diesel travels out to it, drains its fuel tank on the spot then cleans its fuel system of petrol. By the time we go, it is running again on fresh diesel.
When petrol in a diesel C-Class reveals itself
It's often a few miles until the symptoms appear, because with petrol inside your fuel tank a diesel C-Class will often drive normally at first. The following are the ones usually noticed if the fuel tank has AdBlue or petrol in it:
- power falls away, especially when you ask the motor to pull
- rough running, or an erratic idle
- more smoke than usual appears from the tailpipe
- warning lights on the dash come on
- it stalls, then may fail to restart
Check the receipt if one of these began after filling up, as it will show which fuel went in.
Wrong fuel in your Mercedes C-Class and the effect of driving on it
Driving is what takes wrong fuel in your Mercedes C-Class from the fuel tank then on through the fuel filter, your high-pressure pump and your fuel injectors. Until the engine pulls it out, it stays where it is. Petrol weakens the diesel fuel that protects your fuel pump and the fuel injectors while it runs through them, and driving the C-Class further brings the mix into more of your fuel system.
This is the reason to stop the moment you can and not finish the trip. Harm, where it occurs, comes from a long drive on tainted fuel, and a drain and a clean are normally all a vehicle requires when it's stopped early.
Another version of the C-Class is no different from the C 220 CDI Sportcoupe here, so which one is yours makes no difference.
Just where you stopped
You don't have to get the C-Class anywhere. No recovery truck has to be arranged and there is no need to start it, as we come to it at the roadside or outside your house.
A safe place, away from the traffic, is where to wait if you are beside a busy road, with your hazards on.
Roughly how far you travelled, which C-Class it is and where you've pulled up are what to mention when you call 0333 366 0103. If the badge gives the version, such as the C 180 CDI T-Modell, that is useful too.
Fuel drain on your Mercedes C-Class when you've driven it
After it was driven, a fuel drain on your Mercedes C-Class involves one step more than one on the forecourt. Draining the fuel tank comes first. After that we open up the fuel lines and rinse them through with the filter, so there's no petrol remaining between your fuel tank and the motor. With fresh diesel in and your system primed, our technicians start the engine then make sure it runs smoothly.
The tank drained first on the C 300 CDI 4Matic holds 66 litres.
AdBlue in a diesel Mercedes C-Class after it has run
Uneven running, smoke and warning lamps are the normal symptoms once you've driven on AdBlue in a diesel Mercedes C-Class, and the car may stall. As AdBlue settles to the base of the tank, where your pump takes its fuel, it's in your fuel line quickly, and it neither burns nor lubricates. Its water drying out lets the urea form crystals in your fuel lines and the fuel filter.
AdBlue removal from a diesel Mercedes C-Class
The fuel lines and your fuel filter have to be cleared of the crystals once your fuel tank is drained, which is what AdBlue removal from a diesel Mercedes C-Class that has been run means. Where your fuel filter needs it, we change it.
A separate AdBlue tank, if your C-Class has one, is left alone. The job is about liquid in your diesel tank, and does not mean taking out or switching off an AdBlue system.
Tank sizes and engines: Mercedes C-Class fuel tank capacity
Across the versions of the Mercedes C-Class, diesel tanks go from 59 litres in the C 250 CDI 4-MATIC T-Modell to 66 litres on the C 320 CDI 4-MATIC.
One example is the C 220 CDI, which takes 62 litres.
Diesel C-Class versions wear CDI badging.
There are Coupe versions among them.
| Version | Fuel tank |
|---|---|
| Mercedes C 180 CDI | 59 litres |
| Mercedes C 180 CDI T-Modell | 59 litres |
| Mercedes C 200 CDI | 62 litres |
| Mercedes C 200 CDI Sportcoupe | 62 litres |
| Mercedes C 200 CDI T-Modell | 62 litres |
| Mercedes C 200 Diesel | 62 litres |
| Mercedes C 200 T CDI | 62 litres |
| Mercedes C 220 CDI | 62 litres |
| Mercedes C 220 CDI Sportcoupe | 62 litres |
| Mercedes C 220 CDI T-Modell | 62 litres |
| Mercedes C 220 Diesel | 62 litres |
| Mercedes C 220 T CDI | 62 litres |
| Mercedes C 220 T Diesel | 62 litres |
| Mercedes C 250 CDI 4-MATIC | 59 litres |
| Mercedes C 250 CDI 4-MATIC T-Modell | 59 litres |
| Mercedes C 250 CDI blueefficiency | 66 litres |
| Mercedes C 250 CDI T-Modell blueefficiency | 66 litres |
| Mercedes C 250 Diesel | 62 litres |
| Mercedes C 250 T Turbodiesel | 62 litres |
| Mercedes C 250 Turbodiesel | 62 litres |
| Mercedes C 270 CDI | 62 litres |
| Mercedes C 270 CDI T-Modell | 62 litres |
| Mercedes C 30 CDI AMG | 62 litres |
| Mercedes C 30 CDI AMG Sportcoupe | 62 litres |
| Mercedes C 30 CDI AMG T-Modell | 62 litres |
| Mercedes C 300 CDI 4Matic | 66 litres |
| Mercedes C 320 CDI | 62 litres |
| Mercedes C 320 CDI 4-MATIC | 66 litres |
| Mercedes C 320 CDI 4-MATIC T-Modell | 66 litres |
| Mercedes C 320 CDI T-Modell | 62 litres |
| Mercedes C 350 CDI | 66 litres |
| Mercedes C 350 CDI 4-MATIC | 66 litres |
| Mercedes C 350 CDI 4-MATIC T-Modell | 66 litres |
| Mercedes C 350 CDI T-Modell | 66 litres |
| Mercedes C Coupe 220 CDI | 59 litres |
| Mercedes C Coupe 250 CDI | 59 litres |
Pricing a fuel drain on the Mercedes C-Class after a drive
Whether it was petrol or AdBlue affects what a fuel drain on the Mercedes C-Class costs after driving on it, though it depends mainly on how far it went and where it has stopped. Those details are what we need when you phone, and with them we can explain what the work will involve.
Petrol in a diesel Mercedes C-Class: common questions after driving
Is the C-Class ruined now?
Very probably not. With the vehicle stopped soon and the system emptied and flushed where you have pulled up, which is what we do, lasting damage is uncommon.
Should I drive it home first?
It's better not to. We can empty the C-Class right where it is, which means it doesn't need shifting, and each mile driven on contaminated fuel would push it further through your system.
It has stalled and will not restart. What should I do?
Trying again draws more of that mixture through with every attempt. Please leave the vehicle alone. Once we have emptied and flushed it and put fresh diesel in, we prime your system and start it for you.
Does it matter which C-Class I have?
The badge on the tailgate gives the version you have, out of the 36 diesel versions of the C-Class, and knowing it helps us when you call.
Will my policy cover wrong fuel in my Mercedes C-Class?
Misfuelling cover is included in some insurance policies, so do check yours after the car has been sorted out. Whatever it says, we still come out.