In Australia it is almost impossible to accidentally put diesel into a petrol powered car. The Diesel nozzle at the petrol bowser is physically bigger in diameter making it impossible to put a diesel nozzle into a petrol powered vehicles fuel tank. Granted the mistake could still be made via jerry cans and alike but the chances of this happening are far less.
However accidentally putting petrol into the fuel tank of a diesel vehicle is something that happens very often. Unfortunately the petrol nozzle does fit into a diesel power car and many people have unknowingly filled their diesels with petrol.
What should you do if you ever make this somewhat annoying mistake?
There are some dos and don’ts here and if you do the wrong thing here you can make the situation many times worse.
Once you have realised you have made this mistake. DO NOT START THE VEHICLE. Once you start the car the petrol will be pumped through the fuel system. The petrol will go through the fuel pump, the fuel lines and the fuel injectors. The issue with this is diesel has lubricating qualities in it that petrol does not have. By starting the car you are removing the lubrication needed for these components and effectively running it dry. The lack of lubrication even for ten seconds can cause massive damage to these components.
In modern day diesel engines, running petrol through these components means they should be replaced. Granted you can sometimes get lucky and not have to replace everything but more often than not, this is not the case. For some financial perspective here, in some vehicles one diesel injector replacement can cost $3k, multiply that by four, five or six injectors, a new high pressure fuel system and your little mistake just cost you up to $15k in repairs. Do not start the car!
We seem to encounter foolishness a lot in our industry. People drive over heating cars home because breaking down is inconvenient. The consequence is blown head gaskets costing thousands to repair vs a few hundred dollars in a tow truck fee. Petrol in a Diesel falls in the same category. A tow truck is cheaper than the repairs needed if you start the car.
Don’t even start it to get it away from the bowser. If you have to, push it but do not start the car.
If you realise you have done this call a tow truck and get it towed to a mechanic. You may have to pay a few quid to have the tank drained but I can assure you it’s cheaper than replacing the whole system.
If you realise you have made this mistake after you have started the car, turn it off as soon as you realise and hope your one of the lucky ones.