Wrong fuel in a BMW 840Ci? Diesel in a Petrol BMW?

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BMW Fuel Drain


Putting Diesel in a Petrol BMW is a common mistake. And exactly what you should do about it varies according to a variety of things. Assuming you want to find out what to do to fix it then keep reading.
Listed here the most crucial factors to keep in mind when making a decision whether to have it drained:

  1. Exactly how much Diesel did you put in the BMW, bearing in mind that the fuel tank capacity of your BMW 840Ci is probably approximately 90 litres?
    1. A modest amount of Diesel, as little as 4.5 litres of Diesel in a Petrol 840Ci will more often than not not necessarily be a major problem. Experience has demonstrated to us that quantities under 4.5 litres (almost 5% of the entire fuel tank capacity) is in many instances capable of being adequately diluted simply by totally filling up the remainder of the tank with Petrol.
      It's quite uncommon to find a motor vehicle having problems with below 5% wrong fuel contamination. Keep in mind it is very infrequently found - in no way impossible to find. You can get certain vehicles that don't stand any degree of contamination in the slightest.
    2. Anywhere between 4.5 and 9 litres of Diesel in the BMW (from 5 to 10%) is a 50/50 condition. Our working experience has shown that as many people get away with this as all those who break down. When trying to decide whether to chance it and simply top it up remember that it is exactly like betting everything on black - you have got a 50/50 chance of it being ok.
    3. Anything more than 9 litres of Diesel in a Petrol 840Ci should immediately be drained out because your probability of driving with this amount of contamination is certainly below one in 50 - truly long odds.
  2. Put some Diesel in a Petrol BMW and drove it: Have you noted any performance concerns after putting the bad fuel in your 840Ci? If you have, have it drained regardless of the volume of Diesel or even the contamination percentage. Still running a car that is now beginning to suffer from the consequences of fuel contamination can definitely cause more and more damage being done to the fuel system.
  3. Would you like security?
    You should get it emptied. Regardless of the contamination ratio, there is invariably a certain level of danger resulting from driving a Petrol engine on fuel contaminated with Diesel. Possible results of driving on the incorrect fuel can include the motor not starting, running unevenly, lack of power, degradation of the high-pressure pump, worn out or bunged injectors, etc. These are some of the most common Diesel in Petrol signs or symptoms, and in the event that you notice any of them then stop driving and have it removed immediately.

Steer clear of getting any jack-of-all-trades to attend your automobile. We are BMW experts and hold the accreditation and practical experience necessary to ensure that you are back on the road with minimum hassle or worry.

Put Diesel in a Petrol BMW

Unintentionally put Diesel in a Petrol BMW? Or possibly even put contaminated fuel in your BMW 840Ci?

Contact us for Help & Recommendations

Give us a call and receive straightforward guidance and practical help for your precise situation

We arrive and drain it

We are able to reach you to carry out the full contaminated fuel removal & purge there on scene

All done & You Get Going Again

When we are done you should be able to get back moving and get on with your trip

Wrong Fuel Drain Specialists

We are the leading wrong fuel drain experts in the UK, offering countrywide coverage, for BMW motorists in particular. We mainly attend:

  • Unleaded petrol in your Diesel Car
  • Diesel in Unleaded Petrol Car
  • AdBlue contamination
  • Water fuel contamination

We are BMW specialists and have successfully drained hundreds of Petrol BMW vehicles. Regardless of whether it's at the roadside, on a station forecourt, or even at home, we can get you going again.

The Procedure

The procedure of removing Diesel from a Petrol car is fundamentally identical for virtually all vehicle makes. Obviously it does vary to some extent as each make has their unique fuel system. Having said that it still generally observes the following principles:

Petrol in Diesel BMW

Fuel Drain

Empty the Fuel Tank

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Wrong Fuel Drain BMW

System Flush

Clean out the fuel lines & pumps

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Petrol in Diesel Drain BMW

Vehicle Restart

Get the car up and running again

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Diesel in Petrol FAQs

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

I put Diesel in a Petrol 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 Petrol car on Diesel 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 Diesel can I get away with in a Petrol 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 Petrol 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

Should you have any concerns or need our help please Contact Us!
We are able to get you moving again.

24/7 BMW Helpline

0333 366 0103

Our Corporate Office

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


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