Petrol in a Diesel Audi A4: Already Driven It?
If you have driven with petrol in a diesel Audi A4, pull over once it is safe, turn the motor off and keep it off. It's very uncommon for lasting harm to follow if it is spotted early, and it can still be sorted out where you have stopped.
When Petrol in Diesel travels out to wherever your Audi A4 has stopped, the petrol is cleared out of your fuel system and the tank drained. Once we head off, your vehicle is back on clean diesel.
Petrol in a diesel A4: the symptoms to look for
You might go a few miles without spotting anything, as petrol in the tank frequently keeps a diesel A4 driving normally to begin with. Motorists usually spot the following if there's petrol or AdBlue inside the tank:
- the engine lacks power, particularly when you ask it to accelerate
- it idles unevenly, or it runs roughly
- there is more smoke than usual from the tailpipe
- the dash shows warning lights
- it cuts out, and then may fail to restart
One of these beginning after you fuelled up is reason enough to check your receipt to see what went in.
Wrong fuel in your Audi A4 and the effect of driving on it
Wrong fuel in your Audi A4 sits in your tank till the engine pulls it out, and driving is what pulls it through your filter, the injection pump and the fuel injectors. The mix reaches more of your system the further the A4 is driven, because petrol dilutes the diesel fuel that protects the fuel pump and your fuel injectors as it passes through them.
Stopping the moment you can is better than finishing the trip because of that. Damage, where it happens, comes from a long journey on tainted fuel, and a drain and a clean are usually all a motor requires if it is stopped early.
Whether you have the A4 3.0 TDI quattro or any other version of the A4, nothing changes.
Right where you stopped
There's no need to get the A4 anywhere. You can leave it at the side of the road or at home and we come to it, with no restart and no tow to organise.
If you are next to a main road, turn your hazards on then wait somewhere out of harm's way, away from the traffic.
Ring 0333 366 0103 then say where you are, what A4 it is and roughly how far it has been driven. If the badge shows the version, such as the A4 Avant 2.5 TDI, that is useful too.
After it has been driven: fuel drain on your Audi A4
Once it has been driven, a fuel drain on your Audi A4 involves a step more than a drain on the forecourt. Emptying the fuel tank comes first. Then we open the fuel lines and rinse them through with your filter, so there is no petrol left between the tank and the engine. Before our technicians leave, the motor is started to make sure it is running properly on clean diesel, once the fuel system has been primed.
The tank emptied first on the A4 2.7 TDI holds 70 litres.
AdBlue in a diesel Audi A4 after it has run
If you have AdBlue in a diesel Audi A4 and have driven on it, the symptoms are normally rough running, smoke and warning lights, and the car might cut out. The pump picks up fuel at the bottom of the tank, which is where AdBlue sinks, and so it gets to the fuel line fast. It also doesn't burn or lubricate. As its water evaporates, the urea forms crystals in the lines and the fuel filter.
AdBlue removal from a diesel Audi A4
We replace the fuel filter if it needs it during AdBlue removal from a diesel Audi A4 after it's run, when the tank is drained and the crystals are cleared out of the filter and your fuel lines.
Only your diesel tank is dealt with here. If your A4 has an AdBlue tank of its own, it's left alone, and nothing here involves removing or disabling the AdBlue system.
The Audi A4 fuel tank capacity and the engines
The A4 Cabriolet 2.5 TDI is at the top and the A4 1.9 TDI quattro at the bottom of the Audi A4 versions, with diesel fuel tanks from 60 to 70 litres.
A fuel tank of 63 litres is used on the A4 3.0 TDI, for example.
On this diesel A4, the versions wear TDI badging.
Engine sizes go from 1.9 litres in the A4 Avant 1.9 TDI quattro to 3.0 litres on the A4 Avant 3.0 TDI quattro.
Amongst them are Quattro, Avant and Cabriolet versions.
| Version | Fuel tank |
|---|---|
| Audi A4 1.9 TDI | 62 litres |
| Audi A4 1.9 TDI quattro | 60 litres |
| Audi A4 2.0 TDI | 70 litres |
| Audi A4 2.0 TDI e | 65 litres |
| Audi A4 2.0 TDI quattro | 66 litres |
| Audi A4 2.5 TDI | 62 litres |
| Audi A4 2.5 TDI quattro | 60 litres |
| Audi A4 2.7 TDI | 70 litres |
| Audi A4 3.0 TDI | 63 litres |
| Audi A4 3.0 TDI quattro | 66 litres |
| Audi A4 Allroad Quattro 2.0 TDI | 64 litres |
| Audi A4 Allroad Quattro 3.0 TDI | 64 litres |
| Audi A4 Avant 1.9 TDI | 62 litres |
| Audi A4 Avant 1.9 TDI quattro | 62 litres |
| Audi A4 Avant 2.0 TDI | 70 litres |
| Audi A4 Avant 2.0 TDI e | 65 litres |
| Audi A4 Avant 2.0 TDI quattro | 66 litres |
| Audi A4 Avant 2.5 TDI | 62 litres |
| Audi A4 Avant 2.5 TDI quattro | 60 litres |
| Audi A4 Avant 2.7 TDI | 70 litres |
| Audi A4 Avant 3.0 TDI | 63 litres |
| Audi A4 Avant 3.0 TDI quattro | 66 litres |
| Audi A4 Cabriolet 2.0 TDI | 70 litres |
| Audi A4 Cabriolet 2.5 TDI | 70 litres |
| Audi A4 Cabriolet 2.7 TDI | 70 litres |
| Audi A4 Cabriolet 3.0 TDI quattro | 66 litres |
Costing a fuel drain on the Audi A4 after driving
Whether it was petrol or AdBlue changes what a fuel drain on the Audi A4 costs after driving on it, though it hinges mostly on how far it went and where it has ended up. Ring with those details and then we can explain what the job will need.
Common questions after driving with petrol in a diesel Audi A4
Will my A4 be ruined?
Very probably not. With the car stopped early and the system emptied and cleaned wherever you have stopped, which is what we do, permanent harm is rare.
Can I finish the drive home first?
Our guidance is not to. Shifting it isn't needed, because we can empty the A4 where it sits. Driving it on only carries tainted fuel further through your system.
What do I do if it has stalled and won't restart?
Trying again draws more of that mixture through with each attempt. Please leave the vehicle alone. We start it for you after draining and rinsing it, putting fresh diesel in and priming your fuel system.
Does it matter which A4 I drive?
It helps when you ring if we know which of the 26 diesel versions of the A4 you have, and the boot badge shows it.
Insurance and wrong fuel in my Audi A4: am I covered?
Some policies offer misfuelling cover, and so it is worth checking yours once the vehicle is sorted out. We come out either way.