How to Fix a Head Gasket Leak in Your Car

Are you wondering how to fix a head gasket leak in your car? If so, you have come to the right place. We will provide you with a YouTube video from Scotty Kilmer that will cover everything you need to know. We’ll also give you some additional information to go with it.

How do I fix a head gasket leak in my car? 

You have two choices. You can either pull the head off the engine, replace the head gasket, and fix any other damage. Or, you can try putting a head gasket sealer into the radiator to see if that fixes the leak.   

Scotty has some invaluable information about which route to go. He also gives you some priceless tips for helping the head gasket sealer work more often than not.

So, let’s take a closer look at what Scotty Kilmer has to say about how to fix a head gasket leak in your car.

Should I Replace the Head Gasket or Use a Head Gasket Sealer?

Scotty says replacing a head gasket can cost a thousand dollars or more on a modern car. So, it’s worth trying a head gasket sealer first to see if that works. He also recommends using a head gasket sealer called Steel Seal. Scotty has used Steel Seal head gasket sealer for the last two decades, and he says this fix has worked on many vehicles.

There’s More to Using a Head Gasket Sealer Than Just Pouring It into the Radiator

Using a head gasket sealer like Steel Seal is a little more complicated than just pouring it into the radiator. In the video, Scotty shows you exactly how to do this correctly for the best chance for it to work. We are also going to tell you all about it here as well. So, keep reading.

Little Known Tips for Making a Head Gasket Sealer Work

Here are some unique, little-known tips from Scotty for increasing the chances of a head gasket sealer working to fix the problem versus having to have the gasket replaced.

1. Clean Coolant

You first need to have clean coolant in your radiator. So, if it’s dirty, flush it out and put new, clean coolant in it.

2. Remove the Thermostat

Next, take the two bolts off the thermostat housing and remove the thermostat. With the thermostat out, the sealant will have a better chance of sealing the leak.

3. Put the Thermostat Housing Back on

Re-bolt the thermostat housing back on without the thermostat inside of it.

4. Check the Spark Plugs

If you have a head gasket leak, your vehicle is probably using a lot of coolant. So, it is a good idea to check all the spark plugs to see if any of them are burning the coolant.

Take the spark plugs out one at a time and check them. If any of them are covered in antifreeze, look to see which spark plug has the antifreeze on it, and that will tell you where the leak is on the cylinder.

Scotty says to leave the hole empty for the spark plug that was covered in antifreeze. Then you should go ahead and unplug the associated fuel injector as well so it doesn’t fire when you do the next step.

5. Add Head Gasket Sealer and Start Your Vehicle

Next, you will get your Steel Seal or whatever head gasket sealer you decided to use and pour it in the radiator. Then you will start your vehicle.

When you do this, the vehicle will make a lot of noise. But don’t worry; that noise is normal because there is no spark plug in the hole. And, keeping the spark plug hole empty is what helps the head gasket sealer work better.

6. Let the Vehicle Idle

Now, just let the vehicle idle for about 30 minutes, so the head gasket sealer can cycle through the motor and, hopefully, fix the problem.

7. Shut the Vehicle off

After 30 minutes, you can shut off your vehicle and let the engine cool down for another 30 minutes.

8. Repeat the Process

You will then repeat this process about four to five times.

9. Let Vehicle Dry Overnight

When you have finished, let your vehicle dry overnight while leaving the spark plug out of the hole.

10. Reinstall and Reconnect Parts

The next morning, put the spark plug back in, put the thermostat back on, and reconnect the fuel injector.

11. Test Drive the Vehicle

Now take the car for a short drive. You should baby the vehicle for the first 100 miles after using the head gasket sealer, so it has a better chance of seating.

Hopefully, this fixes the problem. But unfortunately, some head gasket holes are just too big for any head gasket sealer to work. However, Scotty says he feels using a head gasket sealer is the best first option. This is because tearing down an engine is an expensive job.

Reviewing Scotty’s YouTube Video Comments

If you read the comments below Scotty’s video, they are overwhelmingly positive. And, a good many of the comments thank Scotty for this fix because it worked for them. Some of the comments were from long-time car repair service people who didn’t even know about Scotty’s method of using a head gasket sealer.

What’s Next?

Would you like to know a little more about your car’s history? If so, go to VehicleHistory to find out.

Checking the history of your vehicle will give you a heads-up about any known issues, so you can watch out for and proactively handle them before they become a problem.