How to fix a blown head gasket

A blown head gasket is a common and potentially serious issue that can affect the performance and longevity of your vehicle’s engine.

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Recognizing the signs of a blown head gasket early on and addressing the problem promptly can save you from more extensive and costly repairs. In this comprehensive guide, we will walk you through the process of fixing a blown head gasket, covering everything from diagnosis to the actual repair.

Why do head gaskets fail?

Before you go about repairing your leaky or blown head gasket, it’s helpful to understand why it may fail in the first place. Head gaskets perform a task which puts an incredible amount of stress on them, so it’s not surprising that some will break down. However, this can potentially be disastrous as far as the efficiency of a vehicle is concerned.

There are two major faults the head gasket can have:

  • Allowing combustion gases to leak out
  • Letting coolant leak in

When combustion gases leak out of a head gasket, it can lead to a loss of compression, engine misfires, and potential contamination of coolant or oil. This results in overheating and damage to the engine.

When coolant leaks in through a head gasket, it can mix with the engine oil, leading to coolant contamination, reduced lubrication, and potential damage to engine components. It also won’t be circulating through the cooling system properly, meaning the engine is at risk of overheating which could lead to a blown head gasket.

A blown head gasket.
A blown head gasket. (Credit: Tony Harrison, Flickr)

Identifying the signs of a blown head gasket

There are several common symptoms that can indicate a leaky or blown head gasket. These include:

  • Overheating
  • White smoke from the exhaust
  • Exhaust gases/bubbles in the overflow tank
  • Milky oil
  • Loss of coolant

Whilst these may all point to an issue with your head gasket, it is always possible that there is an alternative cause. If you’re unsure, it’s advisable to have your vehicle checked out by a local mechanic.

How do you repair a blown head gasket?

Unfortunately, repairing a blown head gasket will more often than not call for a replacement part, and the process can be lengthy and complicated. Below we’ll take you through this process step-by-step to ensure an efficient repair is achieved.

1. Carry out a Diagnostic Check

Once you have identified signs of a blown head gasket, perform a compression test, coolant system pressure test, and exhaust gas analysis for accurate diagnosis. This will assure you before you begin that you are tackling the right issue.

2. Gather Tools and Materials

Collect your tools—you’ll need wrenches and screwdrivers—and necessary materials. Materials include a replacement head gasket, gasket sealer, coolant, and engine oil.

3. Preparation and Safety

Ensure you wear safety gear such as gloves and eye protection throughout the repair process. Disconnect the vehicle’s battery, and always work on a cool engine to avoid burns.

4. Replacing your blown head gasket

Once you’re prepped and protected, it’s time to carry out your head gasket replacement. Follow these simple steps:

  1. Drain Coolant and Oil: This will prevent spills during the repair.
  2. Remove Components: Disassemble components (intake/exhaust manifolds, valve cover, timing belt/chain) to access the cylinder head.
  3. Inspect and Clean: Inspect the cylinder head and engine block for damage. Clean surfaces using a gasket scraper.
  4. Remove the old head gasket.
  5. Place the new head gasket: Ensure proper alignment for maximum efficiency.
  6. Torque Bolts to Specifications: Use a torque wrench to tighten cylinder head bolts to the manufacturer’s specifications.
  7. Reassemble Components: Reassemble components in reverse order of disassembly. Follow torque specifications for each component.
  8. Refill Coolant and Oil: Refill coolant and engine oil to recommended levels using appropriate fluids.
  9. Post-Repair Checks: Perform a coolant system pressure test to check for leaks.
  10. Start the engine: Monitor for abnormalities, and take the vehicle for a test drive.

Remember to prioritize safety throughout the process, use quality materials, and seek professional assistance if you encounter difficulties during the repair.

How to fix a blown head gasket without replacing it

The above process may seem complicated and costly, but it can be avoided. K-Seal can permanently repair and fix most head gasket failures, including:

  • Coolant to cylinder leaks
  • Cylinder to coolant leaks
  • Blown head gaskets
  • Some coolant to oil leaks

All you have to do is shake and pour. Add a bottle of K-Seal to your cooling system and it does all the hard work for you—finding any cracks and leaks and sealing them permanently!

Note: For the best results, it’s important to catch a leak early. This will reduce the risk of further engine damage.

Why motorists worldwide choose K-Seal to fix their head gaskets

The best and most effective head gasket sealer is manufactured by K-Seal – and we say that with confidence. All of the leading roadside repair and recovery organizations use K-Seal technology because it mixes successfully with all kinds of antifreeze and engine coolant to repair failures—preventing combustion gases from escaping and coolant from leaking into the engine cylinder.

Scientifically proven and tested

Tested independently by the engineering department of the University of Brighton to ensure that the products meet industry standards, K‑Seal, K‑Seal Ultimate and K‑Seal HD (designed for use in large vehicles such as HGVs and tractors) are the first choice of motorists on a global scale.

Want to get hold of a bottle to fix your head gasket? Use our simple reseller search facility and get back on the road fast.

Could other parts of my engine be affected?

Although your head gasket could be the source of your engine troubles, it might not be the only component you need to take a look at. Select an engine part in the interactive diagram below to explore your engine and the important components that keep everything ticking over.

Click on the engine components below for details
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K-Seal Repairs Head Gaskets Permanently

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