Bad fuel in your Mercedes ML 420 CDI? Petrol in a Diesel Mercedes?

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Mercedes Fuel Drain


Filling up with Petrol in a Diesel Mercedes is a usual mistake to make. And what you need to do about it is determined by a few things. In case you want to know what you should do about this then please read on.
Listed below are the key factors to keep in mind whenever figuring out whether or not to get the car drained:

  1. Exactly how much Petrol have you put in the Mercedes, taking into consideration that the fuel tank capacity of the Mercedes ML 420 CDI is most likely around 95 litres?
    1. Hardly any Petrol, as little as 4.75 litres of Petrol in a Diesel ML 420 CDI will normally not really be a massive problem. Experience has taught us that quantities under 4.75 litres (which is roughly 5% of the total fuel tank) is in many instances capable of being adequately diluted by completely topping the remainder of the tank with the correct fuel.
      It's highly rare to encounter a motor vehicle experiencing difficulties with under 5% incorrect fuel contamination. Remember that it's rare - certainly not impossible to find. You will discover a few cars that will not endure any level of contamination whatsoever.
    2. Somewhere between 4.75 and 9.5 litres of Petrol in the Mercedes (5 to 10%) is a 50/50 scenario. Our expertise has proven that as many people get away with it as all those who break down. Whenever you are trying to decide whether or not to chance it and just top it up consider that it is the same thing as gambling everything on black - you've got a 50/50 possibility of it working.
    3. Anything in excess of 9.5 litres of Petrol in your Diesel ML 420 CDI must straight away be removed seeing as your probability of driving with that quantity of contamination is probably lower than one in fifty - extremely long odds.
  2. Put some Petrol in a Diesel Mercedes and drove it: Have you seen any kind of performance issues since putting the incorrect fuel in your ML 420 CDI? If so, get it drained irrespective of the quantity of Petrol or the contamination percentage. Proceeding to run driving a car that is starting to suffer the consequences of wrong fuel contamination will probably typically end up in progressively more harm affecting the fuel system.
  3. Do you want assurance?
    In that case get it removed. No matter the contamination percentage, there is inevitably some amount of danger connected with running a Diesel engine on fuel contaminated with the incorrect fuel. Likely outcomes of driving a vehicle on the wrong fuel normally include the engine refusing to start, running unevenly, reduced power, wearing of the high-pressure pump, worn or clogged injectors, and so forth. These are several of the most typical Petrol in Diesel signs or symptoms, and should you observe any of them then cease driving and have it drained asap.

Refrain from getting any unqualified mechanic to try to fix your car. We are Mercedes experts and have got the qualifications and experience necessary to ensure that you get back on the road with no hassle or trouble.

Put Petrol in a Diesel Mercedes

Inadvertently put Petrol in a Diesel Mercedes? Or possibly even put contaminated fuel in your Mercedes ML 420 CDI?

Contact us for Assistance & Recommendations

Contact us and get straightforward guidance and sensible assistance for your exact situation

We show up and do the fuel drain

We are able to go to you to perform the full fuel removal & flush there on scene

All done & You Get Moving Again

As soon as we are done you will be able to get back on your way and get on with your day

Wrong Fuel Drain Specialists

We are the top rated wrong fuel drain specialists in the UK, boasting national coverage, for Mercedes motorists in particular. We principally fix:

  • Unleaded petrol in your Diesel Vehicle
  • Diesel in your Unleaded Petrol Auto
  • AdBlue fuel contamination
  • Water fuel contamination

We are Mercedes specialists and have successfully drained thousands of Diesel Mercedes vehicles. Regardless of whether it is roadside, on a filling station forecourt, or even at your house, we are able to get you on the road again.

The Process

The process of getting rid of Petrol from a Diesel vehicle is essentially similar for most vehicles. Needless to say it may differ a little as every brand has their own different fuel system. Having said that it still follows the following guidelines:

Petrol in Diesel Mercedes

Fuel Drain

Empty the Fuel Tank

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Wrong Fuel Drain Mercedes

System Flush

Clean out the fuel lines & pumps

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Petrol in Diesel Drain Mercedes

Vehicle Restart

Get the car up and running again

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Petrol in Diesel Questions

When someone has put Petrol in a Diesel car they have a few very common questions. So we have compiled a list of the most Frequently Asked Questions for you

I put Petrol in a Diesel car and drove it. What do I do?


Turn off the car as soon as possible and call us. Continuing to run a vehicle on the wrong fuel can potentially damage it. We will be able to give you advice and assistance based on your circumstances

Will driving a Diesel car on Petrol cause damage to it?


It can. However, if the problem is caught and remedied quickly the risks will be minimal. Of the 1,500 vehicles we attend every month, less than 0.5% have suffered and substantial damage requiring parts replacement.

How much Petrol can I get away with in a Diesel car?


The safe answer is none. However you might be able to get away with a very low contamination ratio. That being said, we always highly recommend draining anything over a 5% contamination ratio asap.

I know about petrol in diesel, but what about Super Unleaded?


Putting Super Unleaded, or Shell V-Power, BP Ultimate Unleaded, etc, will have the exact same effect as putting regular unleaded petrol in your diesel car and will need to be drained out and flushed.

Will getting you to do a fuel drain void my warranty?


No! The EU Block Exemption Regulations clearly state that "the work can be carried out by as long as that garage uses manufacturer approved parts and correctly follows the manufacturer's service schedule."

Can I top it up with Diesel and add some 2-stroke oil?


This might work on some vehicles in some cases, but in the majority on instances it won't and you risk damaging the Lambda sensors as well as fuel pump and injectors, just as a regular misfuel.

Contact Us

In the event that you have any concerns or require assistance please Contact Us!
We can get you on the road again.

24/7 Mercedes Helpline

0333 366 0103

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Fuel Fixer Ltd, Linx House, 147 London Road, East Grinstead, RH19 1ET

Weekdays: 9am to 5pm

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