Q: Car is overheating and boiling water out. 2003 Hyundai Elantra

asked by on December 19, 2016

I have replaced thermostat and radiator also installed new valve cover gasket when I installed new radiator cap extreme pressure built and I shut the car off and tried to release cap and it blew off with a loud pop from the pressure so I tried to troubleshoot and found the overflow hose was clogged so I flushed it out Car is losing water via overflow steaming out of the open valve in the overflow cap and old radiator cap. There is a smell of gas that comes out of the radiator and it gets hot way to quickly and the top hose stays hot while the bottom hose is cold but you can see when the thermostat opens after a bit and the water level drops the only thing I can think of would be the head gasket blown or cracked head or possible some kind of blockage keeping the water from flowing through the engine to the radiator at the proper rate can you please give me any ideas or methods of troubleshooting.

My car has 200000 miles.
My car has a manual transmission.

Car is overheating Inspection $94.99 - $114.99 Get a Quote

Hello - you may very well be correct. Given your symptoms, it sounds like you have a blown headgasket. This can be confirmed by checking for low compression between adjacent cylinders, white steam or smoke from the exhaust (smells sweet), and chemically checking for combustion gases in the engine coolant - the "gas" smell you notice in the coolant already. I would recommend an engine inspection by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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


Experienced Mechanic?

Earn up to $70/hr

What others are asking

Front differential
The front differential has a purpose to propel the front wheels, in turn giving your Mercury its 4 wheel drive capability. If you are experiencing abnormal rotational sounds or a clunking or banging during acceleration or deceleration while the 4...
Does my car have rear disc or drum brakes?
The rear brakes on this vehicle will have rotor discs. If you suspect that you have a problem with the rear brakes then you should have a brake safety inspection (https://www.yourmechanic.com/services/brake-safety-inspection) done by a mechanic. One of our technicians can...
Dead battery
This depends on the engine you have in your Ford F250. As you may know, this truck had an option available with a diesel engine which generally would require much more cranking power than the 5.3L motor that would have...
Buzzing noise inside dash 2002 Dodge Dakota
Hi there - several possibilities here for a buzzing sound (https://www.yourmechanic.com/question/buzzing-sound-on-freeway), as this is not an uncommon issue. Quite possibly the auto shutdown relay or the fuel pump relay are buzzing due to burned contacts. There are also instances where...
Tune-up
Hi there. Today's modern cars, trucks and SUV's are much more complex than older vehicles. As such, there really isn't a general "tune-up" service. Instead, manufacturers have created recommended maintenance service, which is unique for each make, model and year....
Rat under Hood.
Of course, you want to be sure that the noise is really from the serpentine belt and/or connected rotating elements. If you simply take all of the belt driven accessories out of the picture by removing the drive belt and...
Why would my 2003 Chevrolet Impala stall and now it runs rough.
Hello. Though there are a lot of things that can cause this typically it is due to an issue with a failure in a spark plug or an ignition coil failure. If there is not a check engine light on...

Related articles

The Best Used Cars to Buy for Teenagers
If If you’ve decided that you’re ready to purchase a used car for your teenager, then you’re probably pretty picky about what you’re looking for. Likely affordability, safety, and fuel economy are high on the list. With that said we’ve...
The Best Used Cars to Buy If You’re Over Six Feet Tall
While While shorter than average drivers can have a tough time finding the right car, it’s equally hard for taller drivers, perhaps more so. If you’re feeling squished, or have to hunch over the wheel to drive, then you’re not...
Symptoms of a Bad or Failing Serpentine/Drive Belt
Common signs include a squealing noise from the front of the vehicle, power steering and AC not working, engine overheating, and cracks on the belt.