Bad fuel in a Mercedes S400 CDI? Petrol in a Diesel Mercedes?

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Mercedes Fuel Drain


Putting Petrol in a Diesel Mercedes is a fairly typical error. And exactly what you have to do about it is determined by a variety of factors. Assuming you would like to know what it is advisable to do about it then stay with me.
Listed below are the key factors to be aware of whenever determining whether or not to have a fuel drain:

  1. What level of Petrol did you put into the Mercedes, taking into account that the fuel tank capacity of your Mercedes S400 CDI is most likely approximately 88 litres?
    1. Hardly any Petrol, something like 4.4 litres of Petrol in a Diesel S400 CDI will in most situations not really be a massive problem. Experience has proven to us that anything less than 4.4 litres (roughly 5% of the whole fuel tank) is frequently able to be completely diluted through thoroughly filling up the rest of the tank with Diesel.
      It's quite unusual to come across a car going through problems with lower than 5% wrong fuel contamination. Keep in mind that it is unusual - in no way impossible to encounter. You will discover a few cars that don't endure any amount of fuel contamination whatsoever.
    2. Anywhere between 4.4 and 8.8 litres of Petrol in the Mercedes (from 5 to 10%) is really a 50/50 scenario. Our working experience has shown that as many people get away with it as those people who don't. When deciding on whether or not to risk it and just top it up remember that it is the same as gambling everything on black - you have a 50/50 chance of it working.
    3. Anything over 8.8 litres of Petrol in a Diesel S400 CDI really should immediately be drained out as your probability of succeeding with that quantity of contamination is undoubtedly lower than one in 50 - definitely huge odds.
  2. Put some Petrol in a Diesel Mercedes and drove it: Have you noticed any performance difficulties after putting the incorrect fuel in the S400 CDI? If you have, get it removed irrespective of the volume of Petrol or even the contamination ratio. Proceeding to drive driving a motor vehicle that is beginning to suffer the effects of fuel contamination will probably definitely result in more harm affecting your fuel system components.
  3. Are you looking for assurance?
    Then simply just get it emptied. No matter the contamination ratio, there is invariably a certain level of risk affiliated with running a Diesel engine on fuel contaminated with Petrol. Possible outcomes of driving a car on the incorrect fuel can include the motor not starting, running unevenly, loss in power, degradation of the high-pressure pump, damaged or clogged injectors, etc. These are some of the commonest Petrol in Diesel signs or symptoms, and if you detect any of them cease driving and get it removed as soon as possible.

Do not just get any unqualified mechanic to try to repair your car. We are Mercedes specialists and have the certification and experience necessary to make certain that you are back on the road with no hassle or trouble.

Put Petrol in a Diesel Mercedes

By mistake put Petrol in a Diesel Mercedes? Or possibly even put contaminated fuel in your Mercedes S400 CDI?

Give us a call for Help & Advice

Contact us and obtain genuine advice and sensible assistance for your particular situation

We come out and drain it

We are able to reach you to undertake the full fuel removal & purge right there on scene

All done & You Get Going Again

When we have finished you can get back moving and get on with your trip

Wrong Fuel Drain Specialists

We are the primary wrong fuel drain specialists in the UK, boasting nationwide coverage, for Mercedes motorists in particular. We mostly attend to:

  • Unleaded petrol in a Diesel Auto
  • Diesel in Unleaded Petrol Car
  • AdBlue contamination
  • Water contamination

We are Mercedes specialists and have successfully drained hundreds of Diesel Mercedes vehicles. Regardless of whether it's roadside, on a petrol station forecourt, or even at home, we are able to get you moving again.

The Process

The procedure of removing Petrol from a Diesel vehicle is fundamentally the same for the majority of vehicle makes. Obviously it can differ slightly as every make has their unique distinct fuel system. Nevertheless it still generally follows the following points:

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 queries or need assistance please Call us!
We can get you moving again.

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0333 366 0103

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

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