• Home
  • Blog
  • How to Look for Symptoms of a Blown Head Gasket

How to Look for Symptoms of a Blown Head Gasket

As car owners, it’s important for us to be aware of our vehicle’s most critical component: the engine. The engine is the head of the car. Without it, everything will be ineffective. Which is why if one part of the engine fails, the car’s performance is greatly affected.

symptoms of a blown head gasket

A blown head gasket is one common problem of the engine. Thus, it’s important to know the symptoms of a blown head gasket. By doing so, this will help you fix it immediately. Also, it prevents any further damage that the other engine parts can sustain.

What’s the Head Gasket?

Many car owners tend to buy cars without ever understanding the internal parts. If you’re one of them, then it’s highly suggested you do a good background check. This doesn’t have to be for every part, just the engine, and transmission for starters.

For the head gasket, the main thing to remember is that its function is to seal the chamber from any leakage. Any engine has a chamber where the air-fuel combustion happens.

This is where the gasket comes into play. It ensures that liquid and oil flows properly between the cylinder heads and the engine block. More importantly, it secures the cylinder heads for maximum compression. Should the gasket be blown, then the engine’s first line of defense breaks down completely.

Things You’ll Need

  • Head gasket sealer – this is the most important item for your blown head gasket. This sealer is a liquid mixture which helps recover the previous form of your head gasket. You can find these online or at your local hardware store.
  • Water/Coolant – Because of the heat escaping due to the blown gasket, you’ll need to add water along with the sealant to keep your car cool. A coolant will also work if you want to take things further.
  • Oil pan – Should your head gasket be blown, draining the oil is a crucial step, so make sure the oil pan is ready.

How to Diagnose Your Car for Blown Head Gasket Symptoms

Step 1: Listen for engine misfires

There’s no better way to check for engine problems that are listening to its performance. Like most engine problems, a misfired sound is the first thing that happens. Don’t only look for misfires, but also check the vibration that the engine produces.

An active vibration might mean that the coolant is reaching the cylinders, causing it to fail upon ignition. You’ll notice it immediately once you see the engine light turn on in your dashboard as well.

Step 2: Look at your car’s exhaust smoke

exhaust car smoke

One of the first symptoms of a blown head gasket is a change in the color of the exhaust smoke. Usually, a good engine will produce a colorless smoke that’s not noticeable from afar.

However, this changes should there be a leakage in the head gasket. The smoke’s color changes because the fluids that go through the cylinder heads and engine blocks are now reaching the combustion chamber.

The chamber should only have an air-fuel mixture in it. When other engine fluids like oils and coolants reach it, a different chemical reaction will occur. Thus, it causes a white smoke that’s very visible even from a distance. Remember, the whiter the smoke becomes, the more serious is the leak in the head gasket.

Step 3: Pay attention to possible overheating

Overheating of the engine is another symptom of a blown head gasket. The fluid mixture in the chamber fails to ignite due to coolant reaching it. As domino effect of that, the coolant mixture leaks and fails to reach areas that need the coolant.

A good way to check if your car is about to overheat is to test the temperature gauge. If it’s approaching hotter levels than normal, immediately shut your engine. Going further with an overheated engine can cause serious long-term problems to the vehicle.

Step 4: Check the oil cap

car engine oil cap

Another symptom is a white buildup under the oil filler cap of your engine. Again, this is another result of a chemical reaction from an unwanted mixture of leaked fluid and air-fuel combustion.

Only check the bottom of the oil filler cap. Should it have a mayonnaise white color under it, then that signifies that the gasket is blown. However, it’s important to note that not all blown gaskets will cause this mayonnaise color in the oil filler.

Step 5: Look for a change in oil consistency

changing oil

By using your oil pan, drain a small portion of oil from the engine. By doing so, you can check for any unnecessary changes in consistency in the oil. A regular engine oil should have no added fluids. So if you notice a separation between the oil, then that means it has coolant mixed in it.

Since coolants are water-based, it will separate easily. Once you see this separation, continue draining the oil because it will cause more problems should you keep it.

Fixing the Head Gasket

Step 1: Jacking up your car

car jack

Like all failing engine parts, a blown head gasket must be addressed immediately. To start, you’ll need to lift your car. This is because you need access to where the coolant cap is. This is where you’ll drain all that coolant that’s been leaking through the blown head gasket.

A crocodile jack should get the job done. Once you’ve jacked it up, secure the vehicle with jack stands. Just jack the front end of your car since you’re only targeting the engine.

Step 2: Drain the coolant

Once your car’s front end is jacked, get a large container that can accommodate all the fluids in the draining process. Align it just below the radiator, where you’ll be removing the petcock.

Once aligned, use a wrench to pry out the petcock. The petcock is just below the radiator, and it looks like a small nozzle with a cap. This will cause the water and coolant to seep out of your engine. To drain the liquid faster, you can remove the radiator cap during this process.

Step 3: Put water in the radiator and disconnect the thermostat

Once all the liquid is removed, simply put back the petcock and tighten it. Then, pour a good amount of water in the radiator. For this step use water only. Once you’re done with that, disconnect the thermostat.

The thermostat is responsible for the passage of coolant to the radiator if things become a little too hot. You’d want to ensure that this doesn’t happen when you add the sealer, so don’t forget to disconnect it.

Step 4: Run your engine

By turning on your engine, the newly added water will be able to circulate inside. Because of this, any added coolant inside will be flushed out the next time we drain it.

Run the engine for a good 10 minutes.

However, if it starts to overheat, turn it off immediately. Once you’re through, turn off the engine and repeat the draining process by removing the petcock. This will drain any remaining wrong fluid in the engine. Also, you can reconnect the thermostat once finished.

Step 5: Adding the sealer

For our last step, you’ll finally be able to use that head gasket sealer. Again, it’s a cheaper alternative than seeking professional assistance, so don’t be afraid to use it.

Before adding the sealer, you’d want to fill a good amount of coolant and water in the radiator first.

A good ratio of coolant and water is 50:50. You can ask for more assistance through your local auto shop. Afterward, get your head gasket sealer and pour the specific amount as indicated in its manual.

Usually, these gasket sealers instruct you to pour the entire bottle. Once you’ve added the amount, recheck the instructions on how many minutes you should run the car in idle. This usually takes around 10-15 minutes depending on the brand you bought.

Wrapping it Up

Checking for the symptoms of a blown head gasket is easy to work. You just need to pay extra attention to your car’s performance, along with other signs we mentioned. This is why examining your vehicle from top to bottom on a weekly basis is a good habit.

Once you see the symptoms, simply follow the steps we provided, and everything should be running well as new. Fixing your car doesn’t have to be troublesome. Just be organized, and your things will be fixed quickly. If you found this article helpful, let us know below and share it with your friends! Good luck!