2016 GMC Sierra 1500 - Diesel in the wrong vehicle

Can diesel mess up a transmission in a gasoline motor

Did you put diesel fuel in the transmission?

Diesel fuel in the fuel tank will not harm the transmission, however it will be difficult to keep a gasoline engine running on diesel fuel. The fuel tank will need to be drained.

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Diesel fuel will “mess up” any transmission in any vehicle.

The real question is…how in the world did someone end up putting diesel in a transmission.

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I think OP put diesel fuel in his tank and was wondering if it would have any effect on the tranny.


If you put diesel into the gas tank, that shouldn’t adversely affect the transmission. But it will cause the engine to run poorly, if at all. As mentioned above the solution is to remove the diesel fuel from the gas tank then refill with gasoline.

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And, it should be noted that, in this forum, we have seen many cases of people with engine problems who assume the transmission to be the source of the problem. This is likely to be one of those cases.

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