Putting petrol in a diesel engine is a common mistake. Unfortunately, even a small amount of petrol can seriously damage your vehicle’s diesel fuel system.
What to do if you put petrol in a diesel car in the Western Cape
Either you realise what has happened straight away (the best scenario) or you don’t.
If you realise the mistake at a petrol station
Don’t start the ignition!
If you’re lucky enough to realise what has happened when filling up or immediately after, don’t start the engine. It’s only once you switch on that the contaminated diesel will be mixed and circulated through the fuel system.
Put the vehicle in neutral and, with help from petrol station staff, push it into a safe spot. Then turn off and arrange for a tow to J.E.G. Diesel.
If an attendant put the wrong fuel in your car (and you clearly stated that you wanted diesel), also make sure you tell the petrol station manager. It’s possible that the garage can be held liable for damage to your vehicle.
Our workshop in Paarden Eiland is the only diesel centre in the Western Cape that’s fully qualified to repair a contaminated diesel fuel system and to claim damages from garages’ insurance. See some of our customer reviews below.
If you don’t realise straight away
Stop driving your vehicle as soon as possible to minimise the damage. Pull over into a safe spot and turn off the engine.
Then arrange to have the vehicle towed to us so the fuel system can be expertly flushed and reconditioned.
Will my insurance or the garage’s insurance pay for repairs?
Repairs after petrol is put in a diesel engine typically range from R60,000 to R100,000.
At J.E.G. Diesel, we can claim these repair costs from garages’ insurance on behalf of our customers.
We have a high success rate in securing payments for our customers. We know the right process to follow and exactly what information garages’ insurers require in reports.
What NOT to do if you put petrol in your diesel car
Three things not to do.
Don’t keep driving
As explained above, your best bet is not to start the ignition at all.
If this advice is too late, stop driving as soon as possible. The more you drive, the more damage will occur to the fuel system and engine.
Don’t try to siphon out the contaminated fuel yourself
This is potentially dangerous. Also, you won’t succeed in completely removing all traces of contamination.
Don’t take your vehicle to a non-specialist garage
Too often, garages or petrol station staff quickly flush out petrol-contaminated fuel from a diesel engine and send customers on their way.
Within weeks or months, the fuel system breaks down.
It requires specialised expertise and equipment to fix diesel fuel contamination.
Once fuel is contaminated, the entire fuel system must be properly treated. The oil tank, filters and cylinders are also likely to be affected. All components should be carefully cleaned, inspected, tested and, where necessary, reconditioned.
It may also be necessary to test and adjust the system’s computer sensors so an optimal fuel-air mix is supplied to the engine.
Without properly qualified assistance, you may face a huge repair bill later on. This could include the costs of replacing the fuel system and repairing engine damage.
Explanation: what happens when you put the wrong fuel in a diesel engine
Accidentally adding petrol to diesel changes the characteristics of the fuel.
Reduced lubrication
Diesel fuel is heavier and more viscous than petrol. It helps lubricate the diesel fuel pump and injectors. These have strict tolerances and operate at very high pressure.
When you add petrol to diesel fuel, the petrol acts like a solvent. It breaks down the lubricant in the diesel.
Because of this loss of lubrication, friction between metal components is likely to damage the fuel pump. It may also produce metal particles. These may circulate and damage the rest of the diesel system, including fuel lines.
Uncontrolled fuel ignition
Diesel has a higher flash point than petrol.
Adding even a small amount of petrol to diesel significantly lowers the flash temperature of the fuel. This can cause the fuel to ignite prematurely. In turn, this can lead to serious engine damage.
In extreme cases, it can damage engine pistons and result in the engine having to be rebuilt.
Incomplete combustion
Contaminated diesel won’t combust completely. If you keep driving, you’ll likely see a lot of black smoke.
The sensors that control your vehicle’s diesel system typically respond by adjusting the fuel-air mixture supplied to the combustion chamber. This non-optimal mixture will negatively affect your vehicle’s performance.
Signs of contaminated diesel fuel
Symptoms of having petrol in your diesel engine can include:
- the engine warning light coming on
- dark smoke coming from the exhaust
- difficulty accelerating
- a clattering noise when accelerating
- difficulty restarting
- the engine stopping.
Always take symptoms like these seriously and have your diesel car, bakkie or truck tested, in case the fuel is contaminated.
J.E.G. Diesel reviews from some of our customers
We’re pleased to have received some glowing reviews from customers who brought us their diesel vehicles after they were mistakenly filled with petrol.
From Marion Kritzinger:
My diesel vehicle was misfueled and driven unknowingly, causing major damage. The manufacturer was unable to provide the necessary diagnostics based report required by the Insurer and my claim against the fuel station stalled. After 5 frustrating weeks went by with no solution in sight I made some calls and was referred to J.E.G. Diesel. Sean immediately took control of the situation and advised me on the way forward. My car was towed to their workshop, the diagnostics were completed and a quote for repairs was sent to the Insurer. Sean and his team assisted me with communicating with the Assessor and the Insurer, which was a great relief. With the comprehensive report pinpointing the exact damage caused, I was able to settle my claim in full and my vehicle was repaired swiftly. I am very happy with the service I received and highly recommend J.E.G. Diesel.
From Youngfolk Media:
A big THANK YOU to Sean and his team from Bosch Car Diesel, Paarden Eiland, Cape Town. It was just another morning, and like many of us, I spent my time in line filling up my car with fuel. But this particular fill up came with disastrous consequences, ‘Diesel Contamination’ from my local Total garage. It was stressful, my car kept cutting out, wouldn’t start, and that night on the way home I broke down on the side of the road, it was not cool!
I knew this was going to be expensive, and I had only two choices, either head over to Land Rover and pay OEM prices or as a friend recommended try Bosch Diesel. I arranged for my Defender to get to Bosch Diesel in Paarden Eiland for an evaluation and Sean and his team took care of it all. They kept me up to speed on what was happening, the expected costs which were half of what the OEM quoted me later on the phone, and then the comfort knowing it was going to be done right was a relief. We all experience some unexpected repairs now and then and there’s just nothing we can do, but it helps to find a trusted repair centre, and Bosch Diesel came through for me. Thank you, Bosch Car Diesel, Paarden Eiland, Cape Town.
From Ezelle Benecke:
These guys were absolutely wonderful to deal with and did a great job! One morning on my way to work someone unfortunately put petrol in my diesel car – my brother told me to phone them and they were friendly, helpful, professional, and gave me feedback throughout the whole process. Shaun helped me & he was super!! Great service 🙂
If you’ve ended up with petrol in a diesel engine in Cape Town (or elsewhere in the Western Cape), contact us online or give us a call on 021 551 9197 – we’ll be able to help!