Have You Put Petrol in a Diesel BMW 5 Series?
Anybody who has put petrol in a diesel BMW 5 Series without starting the motor should keep it turned off, and not start it even to roll it away from the petrol pump. A drain is usually sufficient to set your 5 Series right, provided the petrol remains in your tank, which it will while the motor is off.
Your BMW 5 Series can stay put wherever it has stopped, forecourt or not, because Petrol in Diesel empties misfuelled cars where they are. We will go through it with you over the phone, so ring us before trying anything yourself.
Petrol in a diesel 5 Series: what to do right away
- With petrol in the tank, a diesel 5 Series will normally still start and run, and seem completely ordinary for several miles. That is how people frequently drive off without noticing a fault, and the reason the engine needs to be left off.
- Turning your ignition on is enough, on many diesels, to start the fuel pump priming and pull fuel from the tank to the injectors, so keep that off too.
- Filling up with diesel to thin it is a bad idea, even with super unleaded, which counts as petrol too. The tank on the 5 Series holds up to 70 litres, and every litre of diesel added is more contaminated fuel for us to drain.
- A car blocking a pump can be put in neutral and pushed clear, and the forecourt staff are usually happy to help.
- Ring 0333 366 0103 with the place your 5 Series is and which one it is, the approximate volume of petrol that was put in, and whether it has run. When you can see the exact version on the badging, for example the 525d xDrive, that is useful as well.
Wrong fuel in your BMW 5 Series once your motor has run
Starting the engine is what draws the wrong fuel in your BMW 5 Series out of the tank, and only then does it begin to reach the engine. Whilst it flows through, diesel fuel keeps your high-pressure pump and your injectors lubricated, and the motor depends on that. Petrol thins the diesel and washes that protection away, which is why it's driving any distance on the mix that can cause harm.
Pull over somewhere safe then switch off if the 5 Series has already been on the road. We can still deal with it, by emptying your tank and cleaning the pipes and the fuel filter until all of the contaminated fuel is gone. Very few vehicles that are caught soon and flushed out properly end up with lasting harm.
That holds for the 525xd touring just as much as every other version of the 5 Series.
The fuel tank capacity of the BMW 5 Series
What counts is what share of your fuel in the tank is petrol. The same couple of litres matter more when you fuelled up with the tank nearly empty, which is why its capacity makes a difference.
The tank holds 70 litres on every diesel BMW 5 Series we have figures for, so that sum is the same whichever version you drive.
| Version | Fuel tank |
|---|---|
| BMW 518d | 70 litres |
| BMW 518d Touring | 70 litres |
| BMW 520d | 70 litres |
| BMW 520d Gran Turismo | 70 litres |
| BMW 520d touring | 70 litres |
| BMW 520d xDrive | 70 litres |
| BMW 520d xDrive Touring | 70 litres |
| BMW 525d | 70 litres |
| BMW 525d touring | 70 litres |
| BMW 525d xDrive | 70 litres |
| BMW 525tds touring | 70 litres |
| BMW 525xd | 70 litres |
| BMW 525xd touring | 70 litres |
| BMW 530d | 70 litres |
| BMW 530d Gran Turismo | 70 litres |
| BMW 530d touring | 70 litres |
| BMW 530d xDrive | 70 litres |
| BMW 530d xDrive Gran Turismo | 70 litres |
| BMW 530d xDrive Touring | 70 litres |
| BMW 530xd | 70 litres |
| BMW 530xd touring | 70 litres |
| BMW 535d | 70 litres |
| BMW 535d Gran Turismo | 70 litres |
| BMW 535d touring | 70 litres |
| BMW 535d xDrive | 70 litres |
| BMW 535d xDrive Gran Turismo | 70 litres |
| BMW 535d xDrive Touring | 70 litres |
| BMW M550d xDrive | 70 litres |
| BMW M550d xDrive Touring | 70 litres |
What diesel 5 Series do you have?
The version is normally on the badging on your boot lid, and it's useful for us to know when you ring.
You will also find xDrive and Touring versions in the list.
AdBlue in a diesel BMW 5 Series by accident
To treat their exhaust, some diesel vehicles use AdBlue, a blend of water and urea that is put in its own tank through its own filler. The key should stay out of your ignition when you've got AdBlue in a diesel BMW 5 Series through the incorrect filler, and that covers moving your car.
The fuel pump gets no lubrication whatsoever from AdBlue, which is mostly water and will not ignite. It won't blend with diesel either, and drops to the base of your tank, the same location your pump pulls from, so a tank of up to 70 litres does nothing to dilute it.
Even a little gets sucked into your fuel line. Once the water dries off, the urea forms crystals inside the fuel system, including the fuel filter and injectors, and it corrodes the metal it sits against.
The same flap often hides both fillers, and where your 5 Series has an AdBlue filler, it might well be beside the diesel one. AdBlue caps are normally blue and accept a far narrower nozzle than diesel.
How a fuel drain on your BMW 5 Series works
There is no garage involved, since we do a fuel drain on your BMW 5 Series at your vehicle itself. On the 5 Series the tank takes up to 70 litres, so we empty all of it after we have found out what was put in and whether the motor has been run. Your fuel pipes and the fuel filter are cleaned next, then we refill with clean diesel and prime your system before starting the motor.
By the end, your 5 Series is running on fresh diesel once more and all set for you to take away.
AdBlue removal from a diesel BMW 5 Series, explained
The stages are the same as a petrol drain for AdBlue removal from a diesel BMW 5 Series. We rinse deposits out of the pipes too if the 5 Series has been run, and change the fuel filter if needed, as AdBlue collects in the base of the tank rather than mixing in and can leave them behind.
What we call AdBlue removal is emptying AdBlue from your diesel tank after a slip at your filler, not taking out or switching off the AdBlue system on a vehicle.
What sets the cost of a fuel drain on the BMW 5 Series
The work differs from one job to the next, so we don't publish a set quote. The main things that affect it are these:
- starting or driving the 5 Series, which makes more difference than anything else
- a tank's size next to the amount that went in
- what went in, petrol or AdBlue
- the position of the 5 Series and how easily we can reach it with our van
We can let you know what this work will probably involve when you ring with those answers.
Queries on petrol in a diesel BMW 5 Series, with answers
The BMW 5 Series fuel tank capacity: how many litres?
70 litres. The tank is the same size whichever variant you have.
Is it OK to add diesel after only a little petrol in my 5 Series?
Topping up only lowers the proportion of petrol. None of it is taken out, so it's all still there when you drive off, which is why we would not advise it. With only a little petrol, a fuel drain to get all of it out is generally all the 5 Series requires.
Does my 5 Series need to be taken to the BMW dealer?
There is no need to take it elsewhere. We empty and clean your 5 Series where it is, and we are independent, with no tie to BMW or any of its dealers.
Which 5 Series I have: does it matter?
We hold figures for 29 diesel variants of the 5 Series, and knowing which one you have helps us when you call.
Am I insured for wrong fuel in my BMW 5 Series?
It's worth checking your policy, as misfuelling cover is part of some but not all. Whatever it says, we come out and empty your car.
What happens if I pour diesel in the AdBlue tank of my 5 Series?
Leave the key out of the ignition in that case as well. The AdBlue system will need draining, and when your car is driven like that, it will most likely show a warning and go into limp mode. When you phone, tell us which tank the fuel went into.
Already driven my 5 Series: what do I do?
Stop where it is safe and switch your motor off, then keep it off until we reach you. Lasting damage is very unusual if it is caught early like this, plus we empty the fuel system and clean it where you've pulled over.