Putting petrol in diesel car is a mistake many drivers make, and it can quickly lead to costly damage if not handled the right way. Whether you accidentally put petrol in your diesel car or even drove it a short distance, knowing the signs, risks, and next steps can save you from bigger problems. In Perth and across Australia, car mechanics often get calls about this issue, so let’s break it down in simple terms.
What Happens If You Put Petrol in a Diesel Car?
A diesel engine is designed to run on diesel fuel, which is thicker and more lubricating than petrol. Diesel keeps the fuel pump, injectors, and engine parts running smoothly. Petrol, on the other hand, is thinner and doesn’t provide lubrication.
When you put petrol in diesel car, the first part to suffer is usually the fuel pump. Petrol strips away the lubrication, causing friction and even metal fragments. These fragments can clog the fuel filter, injectors, and lines. If the petrol reaches the engine, pistons may overheat, melt, or crack. The result: your engine can seize or fail completely.
Also Read: 7 Tips For Diesel Car Maintenance
Petrol in Diesel Engine: Immediate Signs
If you have petrol in diesel engine, you might notice:
- Rough idling or engine misfiring
- Strange knocking sounds
- The car stopping suddenly
- Loss of acceleration
- Unusual smoke from the exhaust
If you only filled the tank without starting the car, you’re in luck. But if you drove with petrol in a diesel car by mistake and drove it, the damage can be serious.
What to Do When You Put Petrol in Diesel Car?
1. Do Not Start the Vehicle
If you realise you’ve put petrol in diesel tank, stop immediately. Don’t turn on the ignition. Tell the fuel station staff so they understand why the car is still parked at the bowser.
2. Call Roadside Assistance or a Specialist
Contact roadside assistance, a towing car service Perth, or a misfuelling expert. Many services offer mobile car service Perth or mobile mechanics Perth who can come to you. If you’ve already started the engine, you’ll need a tow truck. (Tow truck Australia services are widely available.)
3. Drain the Tank
A mechanic will drain the fuel either from the filler neck or the tank plug. They’ll replace the fuel filter, flush the system, and prime the fuel lines. Diesel car mechanics Perth have experience with this and can get your car running again.
4. Get a Proper Check
Even after draining, your vehicle needs a free car inspection or professional evaluation. Some auto mechanic workshops or mobile auto mechanic services will do this on-site, while others will require you to bring the car in.
Costs of Putting Wrong Petrol in Diesel Car
The cost depends on whether you started the car. If you didn’t start it, a simple fuel drain and filter replacement usually costs between $200–$500. You’ll also need to refill with the correct fuel.
If you drove the car, you could face repair bills from $1,000 (new pump and filters) to $10,000 (full engine rebuild or replacement). Most warranties and insurance don’t cover wrong petrol in diesel car mistakes.
Petrol in Diesel Car: Insurance and Warranty Issues
Unfortunately, misfuelling is considered driver error. Standard insurance doesn’t cover the costs, and most warranties will be voided if you run petrol in a diesel car. Always check your policy, but don’t expect financial cover for this mistake.
Many workshops and mobile auto mechanic businesses provide 24/7 assistance. Always ask for a free car inspection before committing to costly repairs.
Final Thoughts
If you accidentally put petrol in your diesel car, don’t panic but act fast. Don’t start the car, call for help, and let trained auto mechanic professionals fix it. With the right steps, you might escape with only a small repair bill. Ignore it, and you risk total engine failure and massive costs. Acting quickly also saves time, reduces stress, and ensures that experienced auto mechanic or a trusted mobile car service provider can handle the problem correctly on the spot. Fast response could be the difference between a simple drain and a complete rebuild.
Also Read: Does Air Conditioning Use More Petrol In Car?
FAQs
1. What happens if you put petrol in a diesel car?
Answer: 1
Your diesel engine loses lubrication, leading to fuel pump damage, clogged injectors, and possible engine meltdown. In many cases, the longer the wrong fuel sits inside, the more widespread the damage becomes. If the petrol reaches combustion, uncontrolled detonation can occur, which puts extreme heat on the pistons and valves. Over time, even short drives with petrol in the system can mean permanent failure of critical parts. That’s why fast action is so important.
2. I put petrol in my diesel car but didn’t start it. What should I do?
Answer: 2
Do not turn the key. Call roadside assistance or a mobile car service Perth to drain the tank. The sooner the wrong fuel is removed, the lower your repair bill will be.
3. Can I drive after putting petrol in diesel tank?
Answer: 3
No. Driving spreads petrol through the system and makes repairs much more expensive. Even a few hundred metres can send petrol into the fuel pump and injectors.
4. How much will it cost me?
Answer: 4
Anywhere from $200 for a drain to $10,000 if the engine is destroyed. Costs depend on whether you started or drove the car.
5. Do diesel cars last longer than petrol cars?
Answer: 5
Generally yes, but not if you misfuel them. Correct maintenance and using the right fuel is key. Longevity relies on proper servicing and regular checks by qualified diesel car mechanics Perth.
6. Who should I call in Perth if this happens?
Answer: 6
Look for diesel car mechanics Perth, mobile mechanics Perth, or a towing car service Perth. Many provide on-the-spot help, and some offer free car inspection before quoting repairs.
