What do you do if you have accidentally put petrol in diesel car?

tdiclub.com says: If the tank was mostly filled with diesel, and the gasoline is a smaller proportion so that the engine still runs, the best remedy appears to be to buy a container of injector lubricant additive and cetane boost additive, and "overdose" it to protect the injection pump. Fill the tank completely with diesel to dilute the gasoline as much as possible, and keep driving. In the interest of protecting the engine, it would be prudent to avoid high engine speeds or high engine loads until the gasoline is sufficiently diluted.

If the tank has more gasoline than diesel fuel in it, the engine won't run on that mixture. It will be necessary to drain the tank and re-fill it with diesel. If the car was driven to the point of stalling, it will also be necessary to drain the injection pump housing and replace the fuel filter, and re-prime both of these with diesel fuel.

It depends...

Diesel is a lubricant, and the high pressure pumps used in most common rail diesel injection (CDI) engines - especially from Europe - rely on this for lubrication. Simply turning the ignition on could wash enough gasoline / petrol into the pump to destroy it - starting the engine could result in pieces of metal from the damaged pump reaching / blocking the injectors. Expect thousands of dollars in repair bills to replace the entire fuel / injection system.

So...

If you've filled up with petrol / gasoline - DON'T turn on the ignition, DON'T start the engine - call your breakdown company and they'll arrange to have your tank drained. Inconvenient, but MUCH cheaper.

First answer by Limabee. Last edit by Twyntub. Contributor trust: 63 [recommend contributor]. Question popularity: 166 [recommend question]