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Smell after Trans Flush

I had a trans flush done a few weeks ago and when I picked up the car there was a strong smell in the car( I assumed it was from the flush and that they spilled fluid).The smell was coming through the vents. I needed a cabin filter change and that improved the smell, although occasionally I still get a mild whiff of that same smell through the vents. Does anyone know what this could be? I guess I should have complained about it immediately. It is so hard in the area I live on to get competent mechanics. any clues or help would be greatly appreciated.


You should examine, or have examined, the transmission fluid cooler lines in the event a flush only was performed.
This smell could be caused by a trans fluid spill onto a hot exhaust system component although I would think after several weeks this should be gone if it were an inadvertent one-time thing.

It could also be caused by a still leaking fluid cooler line that was not propery reinstalled and this coud be transmission destroying if that is the case. If the fluid level drops enough due to a chronic leak the transmission may start slipping and once this starts the transmission will be damaged very quickly.

I’m wondering whether you realize that you never actually described the smell. So at the moment it could be anything from somoething transmission-wise that was left leaking, the tech’s old sandwich that he set down & forgot about, or even something else entirely that has nothing whatsoever to do with you having the car serviced.

So maybe try your best to describe what it smells like. Have you - by chance - actually opened the hood and looked around?

I actually just took it in to the shop that did the flush and had them check it out. Everything was dry and no leaks, they raised the car and looked under the hood with me. I will monitor this, but at this point I am satisfied. Especially since the smell has been diminishing to the point of being non-existent.
Thanks for the advice, which I followed. This is one of the best automotive forums I have experienced!

My guess then is that someone did just spill or something of that nature. Transmission fluid can be fairly stinky but it will just dry up & the stink disappear over time if it was spilled.

Either that, or the mice under the hood finally finished eating the tech’s sandwich.