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Transmission Vent Tube Plugged - Gear Oil Smell in car

I have a 2000 Nissan Pathfinder, with a manually trasmission. I replaced the entire transmission a 3 years ago because the prior owner must have run the gears into the ground.

Now, about every 6-8 months the transmission vent tube gets plugged and I get a horrible gear oil smell inside my car. When I take the car in and get the vent tube blown out the smell will stop.

No one knows why this tube keeps getting plugged?

Is there something wrong or is there something I can do to prevent this?

Thank you for any help or suggestions you have. Contact me if you have questions or need more information.


Probably mud-daubbers, some kind of bug building a nest in the vent tube. Stick a little small engine fuel filter in the end of the tube to keep them out…

Hi, thanks for the suggestion. I have a follow up question. I got under my pathfinder, and found two tubes on the top of the transmission, but they were all connected and there would have been no way for a small bug such as a mud-daubbers ( I did look those up ) to get into the tube. I have not been able to find any information on this transmission that would show a vent tube that was open at one end.

Would this be something that I should be able to find on the transmission? Maybe I am looking in the wrong places. I did blow out all the tubes that I found and it has seemed to help a little, but I still have the smell.

Do you have any other suggestions? Should there be a tube that is open at one end? That does make sense to me, I just don’t know where it would be located.

Thanks again, Ron