Petrol In A Diesel Car, What Are The Symptoms?

5 February 2014 | Bruce Compton

So you have just filled your car up with fuel and have gotten back on the road. The only problem is, you have started to experience some strange problems with your car, such as the engine making a lot of noise. You are worried that you may have put petrol into your diesel car and you can’t find your receipt to check. So how do you know if you have put petrol in your diesel car?

The following symptoms are signs of possible petrol contamination in a diesel engine and fuel system:

Petrol In Diesel Car Symptoms

The most common symptoms of putting petrol in a diesel car are the engine will make a loud knocking sound whilst accelerating, the exhaust will produce excessive smoke, idling will be rough, acceleration will be difficult, the engine warning light will come on and the engine might stop and the vehicle will be very difficult to start again, especially when warm. You should never drive your diesel car with petrol.

How to tell if a car is petrol or diesel

Before you fuel up your vehicle, it is always worth checking if it is a petrol or diesel first if you are unsure. There are several steps you can follow to tell if a car is petrol or diesel, such as:

  1. Check for a label on the inside of the fuel door of your car. The label should tell you which type of fuel to use. 
  2. It is possible that the label has been removed or faded. If so, check your dashboard to see if it is recorded there. 
  3. Check your vehicle documentation, such as the owner’s manual to find the fuel requirements. 
  4. If none of these steps are possible, call your vehicle manufacturer’s support line to find out the correct type of fuel.

What You Should Do If You Put Petrol In A Diesel Car

If you are experiencing any of the above symptoms and are worried that you have put petrol in a diesel car, PULL OVER AND SWITCH OFF YOUR ENGINE as soon as it is safe to do so to prevent any further damage. 

Petrol can cause considerable damage to your diesel engine and its fuel system, so stopping your car before any further damage can be caused is paramount and will reduce the various petrol in diesel car symptoms. 

For further information on what damage putting petrol in a diesel car can cause, take a look at our guide. It covers the potential damage that might have occurred to your fuel system and diesel engine, what the long term damage can be and what work might be required on your engine and fuel system to repair the damage. 

Once you have stopped in a safe location, you should call a fuel removal company such Auto Fuel Fix so an engineer can come to your location and carry out a full system flush and clean if required. 

For an in-depth guide into what to do if you have put petrol in a diesel car, check out our handy guide here.

In the event of any petrol in a diesel car misfuelling where you have driven the car, we always recommend changing the fuel filter as soon as possible and having a thorough cleanse of all equipment that could have come into contact with the contaminated fuel. 

If you have put petrol in your diesel car and require assistance, find out how we can assist you with our 24-hour wrong fuel recovery service or call us on 0844 879 4770!