Your car starts billowing white smoke, chugging along to a stop. You call the breakdown assistance people and they send out a technician. He diagnoses that your head gasket is blowing. You’ve heard of this problem before, this is going to be expensive, right?
- What does a head gasket do? What even is a head gasket?
- Why head gaskets fail
- Whats the fix? How much will it cost?
- Why are head gasket replacements so expensive?
- What do you do then if you find you have a head gasket that is blowing? Surely you have to replace it?
- Do gasket sealers work?
- Carry a bottle with you in your car
- Which are the best companies to look out for?
What does a head gasket do? What even is a head gasket?
The head gasket on a car performs a very important role, it mates two major engine components, the cylinder head, and engine block, creating a perfect seal between them. It also has to make sure that no pressurized gases escape from the cylinder bore into the coolant, whilst keeping oil and coolant separate from each other.
Why head gaskets fail
When the head gasket starts to blow, a crack has developed in the seal itself. This can allow gases to pressurize the coolant system, popping radiator caps and overflow tanks. Or it could be allowing coolant into the cylinder bore, which is causing a white smoke to come out the exhaust as well as excess moisture.
It could also let antifreeze into your oil, which begins to emulsify and loses its most important quality, lubricity. Eventually, any of these problems can cause major car trouble, from an overheated engine to one that is completely destroyed.
Whats the fix? How much will it cost?
To fix a blown head gasket, mechanics have to tear down half of the engine. They will have to drop all fluids in the engine bay, including but not limited to the coolant, engine oil, and possibly even power steering fluid.
They have to remove major components like the turbo, exhaust and intake manifolds, power steering and water pumps, fans even, basically anything that is in the way of getting to the head gasket.
Then, the shop has to reassemble everything, following a very specific set of instructions for replacing parts onto the car and bolting them down. The repair bill might top $2000.
Read more: DIY Replacing Head Gasket
Why are head gasket replacements so expensive?
Head gaskets are a fairly cheap component, as are fluids and oils, but the labour will really get you here. Likely, your car will be off the road and in the shop for a few days. It’s a big job and not one that most DIY mechanics are equipped to do.
What do you do then if you find you have a head gasket that is blowing? Surely you have to replace it?
That might not be the case. Recognising the problem that drivers with failed gaskets face, companies have developed numerous gasket sealing products that in some cases can permanently repair the fault.
They work on different principles, some using hight liquid polymers, others ceramic fibers and others still including flax meal in their chemical make-up, but the goal is the same.
To take a bottle of gasket sealer, pour it into the overflow tank and let it circulate around the coolant system, finding the crack in the gasket and sealing it right up. The sealers also have to make sure they only work on cracks and leaks and not gum up the coolant passageways or thermostat for example.
Do gasket sealers work?
Do these products work? Yes, they do, though it does depend on the severity of your crack. If you have a large diameter split in the gasket, the gap might be too large for the sealer to work. But, it’s well worth spending between $10 and $30 on a gasket sealer to at least try this method first.
Carry a bottle with you in your car
It’s well worth carrying a bottle of gasket sealer with you in the car, it might just get you out of trouble in a pinch. There are numerous reviews online that extol the benefits of using these sealants and we’ve tested some ourselves. Click here to read our reviews!
In some cases, the products will even work on cracked hoses, pipes, manifolds and flanges. After trying Radweld on a car of ours, we found it completely stopped our radiator from leaking and the problem never came back.
These sealants are extremely clever and easy to use, just pour right into your radiator or overflow tank and run the engine for 20 minutes. Most if not all recommend dropping the coolant and then refilling the system with water and the sealer for best results.
If you do go down this route, make sure to replace the water with a proper mix of antifreeze right away, especially in winter. Failing to do so could cause more damage!
Which are the best companies to look out for?
We found from our tests that K Seal and Radweld work very well. Other companies offerings such as Steel Seal and Blue Devil have good reviews and come with seals of approval from top mechanics and shops.
The best thing is many of the gasket sealers on the market have a money back guarantee, so even if they don’t work for you, potentially you could get your money back. One business even offers a double your money back guarantee.
If your head gasket is leaking then, give a gasket sealer a try, it could literally save you thousands of dollars.