Wrong Fuel Drain FAQs

Wrong Fuel Drain Birmingham – Frequently asked questions

If you don’t see an answer to your question here, please put in a call to us and ask. A member of our team of wrong fuel drain experts will be happy to assist.

I’ve accidentally put petrol in a diesel car. What do I need to do now?

Firstly, if at all possible do not put your key into the ignition or attempt to start the engine. There is a possibility that running the engine with petrol in a diesel car may damage fuel system components which may invalidate any warranty on your vehicle. Call the Fuel Medic immediately on 0121 6290628 and one of our wrong fuel drain engineers will be with you as soon as possible, to help. In the majority of cases, a small quantity of petrol in your diesel car should not do any damage to the engine and our engineer will completely drain all of the petrol from the diesel fuel tank before topping it up with diesel fuel.


I’ve put diesel in a petrol car. What do I need to do now?

Again, do not turn on the ignition or start the car if possible. It is rare for motorists to put the wrong fuel in a petrol engine car than to put the wrong fuel in a diesel car as the regular diesel pump nozzle at fuel stations is a larger diameter than the fuel tank filling point neck on most modern petrol cars – the fact that the filling point neck won’t accept the diesel pump nozzle means that you have to be fairly persistant to misfuel a petrol car with diesel. If it does happen however, call the Fuel Medic for a wrong fuel drain service straight away and we will come out to you to get you back on the road.


I’ve put the wrong fuel in my diesel car fuel tank, is there any potential damage?

A diesel engine has a fuel system pump that works on very fine tolerances and is lubricated by the diesel fuel running through it. Petrol introduced to a diesel fuel tank acts as a solvent – it compromises the active diesel lubrication which can cause damage to the diesel fuel pump through metal to metal contact of working parts.
Fuel system seals can also be affected by chemical compounds in petrol as well. Usually, the larger the quantity and the further the petrol fuel goes into the system the more potentially expensive the repair costs could be. Most manufacturers would advise that seals and filters ought to be replaced even if the engine has not been started. This particular repair work would not be anywhere near as expensive as an engine replacement and may not be necessary, the engine just needs to be closely monitored for a while after the wrong fuel drain and only if there appears to be a lasting issue should measures be put in place to carry out seal replacement.
Modern HDi diesel engines, or common rail systems, are especially susceptible – if the fuel is contaminated by pump wear debris and this gets into the engine fuel system you may need to replace the low and high-pressure fuel pumps, injectors, fuel rail, line filters and possibly the fuel tank as well. Whilst this is only a possibility, it demonstrates the potential seriousness putting the wrong fuel in your car and then not getting the fuel system drained and flushed professionally.
Many modern diesel engines have a low-pressure electric pump in the fuel tank or sender unit which starts to work as soon as the ignition is activated, which sends the contaminated fuel around the system through the pump and rail – so if you’ve accidentally put the wrong fuel in your car it’s important to not turn the key in the ignition and start the engine. If you have, and most people tend to do so as they only realise what’s happened when the car stalls just down the road from the fuel station, then you need to seriously consider a fuel drain as a matter of urgency to avoid the potentially heavy cost of a fuel system repair.

 Need wrong fuel drain advice? Just call 0121 629 0628