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Q: I went through a car wash with my diesel fuel cap open. I had just filled up. What do I do

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I had just filled up and left my fuel cap open through a car wash. It also does not have the stop in the neck for the nozzles. I'm afraid I could have gotten some water in it

My car has 68000 miles.
My car has an automatic transmission.

Hello. If you are afraid that water or moisture has possibly found its way into your fuel tank, then I would consider draining and refilling the tank. Your vehicle should be equipped with a fuel filter that can catch some of the moisture, however, it may not be able to protect the components if the fuel is heavily diluted.

If a considerable amount of water has contaminated the fuel, the engine or fuel system may be put at risk of potential damage. The best way to make sure that no moisture finds its way into the fuel system is to completely drain the contaminated fuel, and replace it with fresh, undiluted fuel.

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