What’s That Puddle Under the Car?

The most common concern we hear around air conditioning goes something like this:

I keep finding puddles under the engine compartment; I think I have a leak.

The puddle under your vehicle can’t be due to an air conditioning leak.


West Seattle Auto Repair oil spill


Refrigerant, the substance that makes the air-conditioned air blow cold is actually a gas, not a liquid.
So, if your vehicle’s air conditioning system springs a leak, it’s gas that goes into the atmosphere, not liquid forming a puddle under your car.

So, what is it?

The best thing you can do if you’re finding puddles of liquid under your car is to determine what the liquid is:
The 3 most common types would be:

  • Water: if it’s water, and you know you’ve been running the air conditioner or interior heater, it’s likely just condensation from the cooling mechanisms. Specifically, the evaporator core leaks water from under the passenger side of the engine compartment when the air conditioner is being used. This is normal use.
  • Coolant: if the liquid smells sweet and appears to be tinted or colored (yellow/green), it could be coolant. Coolant regulates the engine temperature and you should definitely bring your vehicle to the shop if you suspect the puddles are coolant.
  • Oil: Thick and dark, you’ll know it’s oil by the viscosity, color, and smell, plus it’s tough to clean up! If you’re finding oil under your car or truck, please give us a call right away.

If you’re unsure about how to check which liquid it could be, just come by.
We’re never too busy to make that determination for you.

It’s important to keep your vehicle safe, and to give you peace of mind too!

Explore more:
Your Air Conditioner Is a Multi-Purpose System
Finding the Leak in Your Air Conditioning System