Skip the auto shop - Our mechanics make house calls

Q: Overheating car

asked by on

I put water in my car, but left the cap off and it started smoking white smoke, so I put the cap back on and the car overheated, took the cap off and heaps of water came out, and now the car keeps overheating what do I do?

Hello, thank you for writing in. To start lets discuss the radiator cap. The system is designed to work under a certain amount of pressure. If the cap is off, the pressure will release through the opening and cause it to overflow. If the system is overheating with the cap on, then there is a different issue. The first thing to consider is the water pump. If this is not providing adequate flow through the system, then hot coolant stays around the engine and does not transfer heat away from it. This will lead to overheating. The thermostat can also cause overheating by lack of coolant flow. It does this by not releasing new cold coolant into the passages around the engine. Check into the condition of these two components and take further diagnosis from there.

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!

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: High idle, loss of power, overheating

Hello. Thanks for writing in about your 1994 GMC K1500 Suburban. A dirty throttle body will cause the power loss and RPM fluctuations. Also, a thermostat opening slow could be the cause of your overheating concern. This should be checked...

Q: I changed my thermostat and my truck is still overheating.

The next thing to check would be the fan or fan clutch. The hot coolant in the radiator cannot be cooled if there is not enough airflow across the radiator and this would be the result of a weak fan...

Q: Rough idling - 1990 Chevrolet G30

This could be an issue with a blown head gasket. This would require a professional mechanic to check engine compression as well. This can occur without causing oil/coolant mixing. If you are still having trouble, a certified technician from YourMechanic...

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...
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...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...