A few weeks ago, at a 76 station, I pumped about 10 gallons of what was supposed to be unleaded gasoline into my 2011 RAV4 V6 Sport. Turns out the tanker was accidentially loaded with a mixture of diesel and water. Vehicle sputtered to a stop about a mile from the gas station, tried to start it a few times but it would just stumble and die. Check engine, VSC and 4WD lights were on . Had it towed to the closest Toyota dealership where they discovered the fuel contamination. They drained the tank, refilled it and ran it down to 1/4 tank. When I picked up the vehicle it was running a little rough, which the service advisor said it might do. Filled it up at a Chevron station close by and got about 1/2 mile away when the vehicle started to stumble, check engine, VSC and 4WD lights came back on. Returned to the dealership where this time they drained the tank again and waited longer for it to completely drain due to the tank design. They also road tested it for 50 miles before giving it back to me. It has run fine since then. My question is there any problems to the engine that this contamination may cause in the future?
Did the Toyota mechanics inspect the spark plugs at all? Check emissions? We cannot tell if they did a thorough job. Let’s assume they did. If so, there should be no permanent effects to the engine, and you may now drive without further worries.
try a different fuel stop
This should not have done any long term damage. Diesel fuel is a lubricant and the water will evaporate very soon after the engine is run with good gas.
Had it sat around for a few days before you got it fixed, it might have a small long term affect, but if you got this fixed right away, should be no problem.
I doubt it did any permanent damage. It could possibly have damagde the O2 sensors or the cat converter I suppose. Possibly the fuel injectors. But if it is running fine and all the dashboards lights are back to normal, no check engine light, it has all been flushed out, and you are probably good to go.