Skip the auto shop - Our mechanics make house calls

Q: Coolant leaking from top of coolant tank

asked by on

I was driving one day and when I came home and parked my car a few hours later noticed a very small puddle of coolant on the ground. Popped the hood and saw that the coolant was low. Top it with with some water and left it. A week later I was driving and noticed the temp gauge was fluctuating above 50%. I went to gas statioN to get gas and all my coolant started leaking out of nowhere. Popped open the hood and the cap was loose but still on and all the coolant had overflown out of the tank and down the sides.

My car has 70000 miles.
My car has an automatic transmission.

You either did not get the coolant cap tightened completely when you topped it off before or you have a defective cap. Replace the cap and refill the system while making sure the cap is on all the way. If the problem persists and you suspect something is wrong, then have a certified mechanic, like one from YourMechanic, diagnose the coolant leak firsthand for you. Good luck.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. Coolant leaking from top of coolant tank

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Transmission leak

The pan is the most common leak area on these transmissions, but it would need to be inspected to see if the case, or filter, is the cause of the leak. If you are low on fluid, I recommend that...

Q: Code P0420. Need to replace catalytic converter.

Hi there. The code P0420 is coming up for the Downstream Oxygen sensor has picked up an abnormal reading and is saying that the catalytic converter is below threshold. There could be a misfire on the engine, leaking injector, ignition...

Q: hello, my coolant was leaking so I had a mechanic repaired it and it was fine for a day and then the next morning I saw the antifr

Coolant leaks may come from a variety of places such as any of the hoses that go to or from the radiator to the motor, the thermostat housing, the water pump or potentially the radiator itself. I would suggest having...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...