Petrol in a Diesel Audi A3? Leave It Switched Off
We'd urge you to leave your motor off if you've put petrol in a diesel Audi A3 and not run it yet, and that counts for moving it off the forecourt as well. That petrol can't get out of your tank whilst the engine is off, so your A3 can usually be put right with a fuel drain.
Your Audi A3 can be left wherever it ended up, forecourt included, because Petrol in Diesel empties misfuelled vehicles where they are. Phone us first then let us talk you through it, rather than trying anything on your own.
Put petrol in a diesel A3? The first steps
- Leave your engine off. Any diesel A3 will normally start and run with petrol in its tank, and it can feel fine for a couple of miles, which explains why drivers commonly drive away without realising something is amiss.
- Switching the ignition on is all it takes, on plenty of diesels, to start the fuel pump priming and draw fuel from the tank towards the injectors, so keep that off too.
- Don't fill the rest of your tank with diesel to weaken it. The A3 takes up to 62 litres, and topping it up only leaves more tainted fuel to drain. Super unleaded is petrol here too.
- Forecourt attendants will generally help push the vehicle out of the way in neutral when it's blocking a pump.
- Call 0333 366 0103 with where your A3 is and which one it is, the approximate volume of petrol that was put in, and whether it has been run. If you can see the exact variant on the badge, for instance the A3 1.9 TDI, that is useful as well.
What running the engine does with wrong fuel in your Audi A3
Wrong fuel in your Audi A3 only begins to reach your engine after it is pulled out of your tank, which is what starting your engine does. A diesel motor depends on the fuel to oil the high-pressure pump and your injectors as it flows through them. Driving for any distance on that blend is what can do damage, since petrol dilutes the diesel and strips that protection away.
Once you've driven your A3 on it, the thing to do is stop somewhere safe then switch your engine off. It can still be sorted out, with your tank drained and the lines and filter cleaned till the last of the contaminated fuel has been removed. When it's caught early and flushed out properly, long-term harm is very unusual.
The A3 Cabriolet 1.6 TDI is no different here from any other version of the A3.
Audi A3 fuel tank capacity
What matters is what proportion of your fuel in your tank is petrol. The same couple of litres count for more if you fuelled up with your tank nearly empty, which is why its size makes a difference.
Tank capacities for the Audi A3 go from 50 to 62 litres depending on the version.
According to our data the A3 1.9 TDI quattro has the biggest tank and the A3 Limousine 2.0 TDI the smallest.
The A3 2.0 TDI quattro has a tank of 60 litres.
| Version | Fuel tank |
|---|---|
| Audi A3 1.6 TDI | 55 litres |
| Audi A3 1.9 TDI | 55 litres |
| Audi A3 1.9 TDI quattro | 62 litres |
| Audi A3 2.0 TDI | 55 litres |
| Audi A3 2.0 TDI quattro | 60 litres |
| Audi A3 Cabriolet 1.6 TDI | 55 litres |
| Audi A3 Cabriolet 1.9 TDI | 55 litres |
| Audi A3 Cabriolet 2.0 TDI | 55 litres |
| Audi A3 Limousine 2.0 TDI | 50 litres |
| Audi A3 Sportback 1.6 TDI | 55 litres |
| Audi A3 Sportback 1.9 TDI | 55 litres |
| Audi A3 Sportback 2.0 TDI | 55 litres |
| Audi A3 Sportback 2.0 TDI quattro | 60 litres |
Working out which diesel A3 you have
Most of the time the variant is shown on your boot lid, and it is useful to us to know when you ring.
The diesel versions of the A3 were badged TDI.
The A3 2.0 TDI has the largest engine, at 2.0 litres, and the A3 Sportback 1.6 TDI the smallest, at 1.6 litres.
You can also see Sportback, Cabriolet and Quattro versions on the list.
AdBlue in a diesel Audi A3
AdBlue is a blend of water and urea that some diesel vehicles use to clean up their exhaust, and it has a separate tank and filler. Pouring AdBlue in the incorrect filler gives you AdBlue in a diesel Audi A3, so don't touch your key, not even to shift the car.
AdBlue settles to the base of your tank, where your pump draws its fuel from, because it will not mix with diesel. Being largely water, it can't ignite and leaves the fuel pump with no protection, and your diesel in a tank holding up to 62 litres does not thin it as it would petrol.
A modest quantity is still sucked into the fuel system. When the water has dried off, what is left is urea, which forms crystals in the system, filter and injectors included, and attacks any metal it touches.
On many motors the AdBlue filler sits beside the diesel filler under the same fuel flap, and if your A3 has one, it could well be there as well. The nozzle for AdBlue is far smaller than the diesel one, and the filler cap is usually blue.
Fuel drain on your Audi A3: what we do
There is no garage involved, because we do a fuel drain on your Audi A3 at the car itself. We begin by checking what was put in and whether the motor has been run, then drain the tank, which on the A3 takes up to 62 litres. After that we clean your fuel lines and the filter and refill with clean diesel, and the system is primed before we fire it up.
On the A3 Sportback 1.9 TDI the tank takes 55 litres.
You can drive your A3 away when we've finished, running on clean diesel.
How we handle AdBlue removal from a diesel Audi A3
Like emptying petrol, AdBlue removal from a diesel Audi A3 runs through the same steps. When the A3 has been run, AdBlue may form crystals inside the pipes, because it collects under the diesel instead of mixing in. We rinse those through too, and replace the fuel filter if it needs it.
On this page, AdBlue removal means taking AdBlue back out of a diesel tank it was put into through the wrong filler. Switching off or taking out the AdBlue system on a car isn't what it means.
Pricing a fuel drain on the Audi A3
The work changes from one job to the next, so we don't publish a set quote. The biggest factors that affect it are these:
- whether the A3 has been started or driven, which makes the greatest difference
- a tank's capacity next to the amount that was put in
- which of the two it was, petrol or AdBlue
- where the A3 is, and whether we can bring the van to it safely
The A3 Sportback 2.0 TDI quattro holds 60 litres when full, by comparison.
With those answers on the phone, we can tell you what the work is going to involve.
Questions about petrol in a diesel Audi A3
What is the fuel tank capacity of the Audi A3?
Somewhere from 50 to 62 litres, depending on which version it is. Every one is listed above.
Is it all right to add diesel after just a little petrol in my A3?
We wouldn't advise it. Putting in diesel cuts the proportion of petrol without taking out any of it, so that petrol is still in the system when you drive off. All of that is removed with a fuel drain, which for a modest amount is normally everything your A3 needs.
Does my A3 need to be taken to the Audi dealer?
You don't need to. We have no tie with Audi or any of its dealers, being independent, and your A3 is drained and cleaned wherever you are.
Does it matter which A3 I own?
Knowing your variant is useful when you phone, as there are 13 diesel variants of the A3 in our data.
Does my insurance cover wrong fuel in my Audi A3?
Misfuelling cover is part of some policies and not others, so check yours. We'll come out to drain it for you whether it does or not.
The diesel went into the AdBlue filler on my A3. What now?
In this case, too, the right thing is to leave your ignition alone. Limp mode and an alert are what the majority of cars show you if they're driven like that, and their AdBlue system will need draining. Do say which tank took your fuel when you phone.
Already driven my A3: what do I do?
Till we arrive, your motor needs to remain off, so stop where it's safe and turn it off. Wherever you have pulled over, the system is emptied and cleaned there, and caught early like this, it very seldom leaves long-term damage.