Unexplained powder leak under car
Powdery residue or thick wet powder under the car often originates from a leaking air conditioning drain tube after heavy use. This residue leaves motorists confused about whether it signals a severe mechanical failure or simply a localized AC system issue.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1Checking coolant levels
- 2Inspecting for puddles on the ground while parked
- 3Taking the vehicle to local shops for diagnostics
- 4Continuously recharging the air conditioning system
- 5Asking online mechanics to identify the fluid based on descriptions or photos
- 6Asking online forums to identify fluid colors
- 7Tasting the fluid to check for sweetness
- 8Checking if the fluid glows
- 9Dipping a finger in the fluid to smell or taste it to identify what it might be.
In their words
Unedited, most upvoted first, each linked to the thread it came from.
“This morning I noticed a wet spot underneath. Any thoughts?”source ↗
“Was doing oil change in car and saw on passenger side of car this wet looking spill. When touched it was powder really thick powder I removed the cover but saw nowhere where this could come from??”source ↗
“It’s powdered though? Never seen a previous car do that maybe I’m missing something.”source ↗
“The open tube in focus is leaking something. My vehicle has been having AC issues through this hot summer and I've had to recharge it multiple times.”source ↗
“The leaking fluid has made a puddle with a rainbow oily look.”source ↗
“I notice this strange green liquid on the driveway and im assuming this has to do something with Mechanic and since I have no knowledge over that type of stuff, I’m asking you guys to see if any of you are able to identify this”source ↗
Where this came up
People with this problem also raised
- 5Is a clear fluid leak from my car or heat pump dangerous?
- 4Mystery part fell out during car repair — what is it?
- 4Is my outside unit leaking oil or condensation?
- 3How to identify a mystery liquid leaked inside my car
- 18How to identify a random car part that fell off
- 2How to figure out where a power steering leak is coming from