I accidentally put the wrong fluid in my car
Adding the wrong automotive fluid causes immediate contamination that can destroy engines or cooling systems if circulated. Drivers dealing with this mistake face potential component damage and costly emergency flushes, though catching the mix-up early or in small amounts can sometimes limit the severity of the damage.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1siphoning or turkey-basting out the reservoir tankDid this help you?
- 2rinsing and refilling the reservoir with correct coolantDid this help you?
- 3draining the system completelyDid this help you?
- 4drain and refill asapDid this help you?
- 5Siphon out the fuel, refill with diesel, and open the fuel system near the engineDid this help you?
- 6Drain the tank, fuel lines, pump, and injector lines, then blow out with compressed air and replace fuel filtersDid this help you?
- 7Get the vehicle towed to a shop to have the tank drained and the fuel system flushedDid this help you?
- 8Siphoning the diesel out of the tankDid this help you?
- 9Disconnecting the fuel line to pump out the remaining fuel using the car's fuel pumpDid this help you?
- 10Diluting the remaining diesel with gasolineDid this help you?
- 11Replacing spark plugs and cleaning or replacing fuel filtersDid this help you?
- 12Having the cooling system flushed and refilled with the OEM-recommended coolantDid this help you?
- 13Leaving the incorrect coolant in the vehicleDid this help you?
- 14Having the system flushed again and replacing it with the manufacturer-recommended coolantDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“How do I fix? She was able to limp home. Smoking everywhere. Now it won’t even start and is sitting in the street in front of the house.”source ↗
“She was close to E and only put in $10, so about 2 gallons. If I fill it up and dilute the diesel with 14 gallons of gas would that work or should I stick with siphoning the diesel out?”source ↗
“I accidentally put petrol in my diesel car.”source ↗
“Yes, I did drive it for about 15 minutes”source ↗
“So i accidentally pour the wrong coolant on my car , i should've know better , i did realize it when i was pouring and stopped myself from adding more , here's how much I poured , how much should I worry ? I know ima have to get it flush once I have the money for it”source ↗
“My mechanic used NAPA NEBB53 European Blue HOAT coolant instead of VW G12++/G13.”source ↗
“Is this coolant compatible, or should I have it flushed again? Could leaving it in cause long-term damage?”source ↗
“It’s 11 o’clock at night so it’s sitting on the side of the road currently”source ↗
Where this came up
People with this problem also raised
- 2Accidentally put the wrong oil in my car
- 5What happens if you overfill engine coolant past max line?
- 2How to tell if a mechanic actually changed your car fluids
- 2Dirt or plastic fell into my engine oil fill hole
- 20How to choose between multiple equivalent automotive fluid specs
- 6Is wrong brake grease bad or should I clean it off?