Q: Car still overheating, and hissing, even after changing the coolant.

asked by on

My coolant service light went off, so I went directly to the dealer to buy coolant. After changing the coolant the coolant service light went off again. I opened the hood and heard hissing noises. I believe it is a hose, but I can't determine which one.

Hi there. Some coolant leaks can be hard to find and may only appear when the system is under pressure. If you are getting a hissing noise it is possible that you have a leaking hose, but most of the time on this model VW it is caused by a leak in the radiator or the water pump. If the leak is not visible by looking around the engine compartment then it would be best to consult the help of a certified mechanic, like one from YourMechanic, that has a cooling system pressure tester. With this tool they can pressurize the cooling system in order to more easily identify the source of the leak.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 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. Car still overheating, and hissing, even after changing the coolant.

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: Vehicle overheated and messed up water pump

Hi there. The Check Engine Light came on due to the extreme temperature your vehicle reached. Your sensors will light up the Check Engine Light as a warning to shut off and cool the engine. A damaged water pump/ hoses...

Q: When we start the car, the engine shakes and makes a noise. In about 5 seconds, it cuts off. What's the problem?

In general, the engine vibration you're referring to is caused by a restriction of fuel flowing into the engine. This can be caused by dirty or clogged fuel injectors, a bad idle control valve, or the throttle body being dirty....

Q: Smoke started coming out of my Jeep engine. I stopped driving, had a look, I believe my serpentine drive belt has snapped.

Several faults can cause your serpentine belt to snap. If the serpentine belt snapped it should be fairly easy to see. The belts fail for many reasons but the most common would be a failed belt, seized accessory, belt tensioner...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
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...