3 Reasons You Know That it is Time to Replace Your Head Gasket

Sometimes bad things can happen to good engines. This can be the case with a head gasket failure. Depending on the design requirements and the suitability of your gasket material for the application, the useful service life will vary. However, any application that is in use long enough may require a replacement of the head gasket.

Head gaskets are one of the more difficult repairs on an engine. They require substantial removal of parts, careful cleaning and preparation of surfaces, and methodical replacement and reassembly of the engine components. Nobody really WANTS to replace a head gasket, but sometimes, it’s just necessary.

How do you know when this is needed? Here are a few warning signs:

It’s time to replace your head gasket when there is…

1. Loss of compression

Failure of the combustion seal results in a loss of compression in the engine and loss of power. This is normally obvious when it occurs and requires a replacement of the head gasket right away.

2. Coolant in the oil (internal loss of fluid)

If the body of the gasket loses load and leaks coolant into the oil ports, bad things happen. The oil will be compromised in its lubricity, resulting in possible damage to the internal engine parts. It may also result in excessive heat and other failures. This requires replacement of the head gasket immediately.

3. Leakage down the block (exterior loss of fluid)

The body can also fail to seal the fluid ports resulting in external leakage of the fluid (either oil or coolant) down the side of the block. This can be a more gradual failure of the head gasket and often not noticed until much later.

Replacing a Head Gasket

If you have arrived at the decision that a head gasket needs to be replaced, you need to be aware of a few things.

1. Know that you may not be able to replace it with a similar gasket material without significant repair cost also put into the flanges.

Why? If the original gasket was a MLS (multi-layer steel) construction, this will require extremely smooth surface finish preparation (which equals repair costs). There are other gasket material technologies out there that will save you from this cost.

2. There are various types of replacement head gaskets available.

Graphite products are an excellent choice and can be made to the required thickness and density to meet your needs.

3. It is a complicated repair and replace operation, but not impossible.

Once completed, the engine will have a new lease on life for many more happy miles.

If you have any questions about what you’re seeing with your gasket material, or are looking for suggestions on the types of gasket materials that will work best when a head gasket is being replaced, talk to your trusted gasket material supplier. They will be able to get you going in the right direction.

Is there anything you would add to the warning signs list?Corseal product comparison

What To Do If Your Gaskets Continue To Blow Out

Is it Groundhog Day? You may feel like it if your life is a never-ending saga of blown gaskets. At some point, it’s time to say enough is enough and figure out what you need to change in order to prevent this problem from occurring again.

Your first instinct when a gasket is blown should not be to immediately try a different gasket. There are many things that could be the root cause of your issue, and unless you understand why the gaskets are failing, you are probably going to wake up tomorrow and have the same problem.

So What Next?

Ok, so you’re now staring at an application that isn’t running, and you are holding a blown gasket in your hand. How should you be troubleshooting this? There could be any number of issues. Here are some of the more common problems and why they can cause a blowout. Hopefully at least one of these will get you pointed in the right direction.

1. Temperature

How hot is your application running? One of the most common culprits of gasket issues is heat and the reality that your application is running hotter than you think. Do some additional testing, consider the peak exposure, and select a material that is designed to survive those conditions.

2. Pressure

Are you expecting your gasket to seal a high pressure joint? If so, is your gasket reinforced? Metal reinforced gaskets can provide enough radial strength to hold up to the high pressure.

3. Assembly

Ensure that your joint is properly assembled. There are recommended torque values as well as a sequence that should be followed. If you are using a compressible gasket, a final torque once operating temperature has been achieved is helpful to maintain load over long term service.

4. Flange Loading

This is one of the most critical pieces of the bolted joint. Without the proper loading, no gasket will seal. Be sure that the flanges are in good shape and have adequate flatness and surface finish. Loading needs to be sufficient to establish an initial seal but also maintain load to seal the joint over the long term, after the initial heat cycles.

5. Thickness

How thick is your gasket? In most cases, the thinnest gasket you can use is the best choice. There are a few instances where you would want to increase the thickness (ex. compensating for flange conditions). Thinner gaskets have less chance for blowout since the load is concentrated over less volume, which provides higher shear strength.

6. Material Type

If you’re sealing fluids, be sure that the gasket material is compatible with the fluid and will not degrade over exposure time. Think of using a plastic bag to hold water vs a paper bag.  Both will hold water, but the paper bag has a clock ticking.

Moving On

Sometimes, none of the above gives you any insight into your problem. These are the difficult ones to fix. Unfortunately at this point, it tends to boil down to a less than ideal joint design and the difficulties associated with finding a gasket material to compensate for these issues. Obviously, if you have gotten this far in the process, changing the design probably isn’t going to be an option (unless it is really bad). It is up to you and your trusted gasket material supplier to find a material that is going to work. In most cases, you’ll find something that’ll seal. However, you may be in a situation where you find that you need to design a material to meet your specific needs. If your gasket material supplier isn’t willing to help walk you through your options, be sure to find someone that is.

What causes most of your blown gaskets?

Case Studies

6 Warning Signs That You May Be On The Path To A Poor Gasket Design

You may be wondering what a gasket material supplier is doing writing about poor gasket design. Over the years we have seen our fair share of design flaws, and just before launch, everyone is scrambling to find a gasket material that will make up for the deficiencies in the design. We are here to tell you that it doesn’t have to be this way! Sometimes the best gasket design can come from choosing the right material in the first place.

More than a few times in our 20+ years of business, we have been called upon to suggest a material for an application before the design is finalized. With our line of metal reinforced composites, we can offer a solution that is going to seal most joints successfully. We are also on the front end of a lot of gasket designs as well. We are proud to partner with OEM’s and fabricators and provide design assistance, which helps avoid the scramble at the end when the design and material don’t play nicely together.

If you are currently designing a gasket, or may ever design a gasket, read on for some gasket design warning signs and how they can negatively affect how well your gasket will seal…

Some Common Problems & Their Potential Solutions

1. Temperatures are too hot, the material is burning up.

It may be aging with the heat exposure, requiring that a higher temp material be used.

2. Internal pressure is too high, gasket is leaking.

Designers should be sure that sufficient flange load is available to obtain an initial seal and then maintain it over the long term.

3. Material is crushing or splitting, gasket is leaking.

This may be a result of too much flange load, or the design of the flange itself. It may also be a result of material that is not correct for the application, or it might be too soft for the designed flange load.

4. Gasket is fracturing due to expansion/contraction, creating a leak path.

High temperatures can cause flanges to move with the heat expansion. Some materials will not tolerate this growth and contraction and tear apart. This can be rectified with a surface coating (anti-slip) or a different material altogether.

5. Gasket is not suitable for the fluid contained.

Compatibility should be verified so it does not degrade when exposed to fluid.

6. Gasket material may be swelling, indicating that degradation is present.

Some degree of swelling is typically acceptable. However, excessive swelling is an indicator of breakdown of the material and a suggestion that long-term performance may be questionable.

Now You Know

Even though there are technically advanced gasket materials out there, nothing beats a great design. As a design engineer, your #1 goal is to design something that will meet the requirements of your application. Getting your gasket material manufacturer involved before testing to ensure the design and the gasket material will work together is only going to help you achieve your goal.

Why not do everything you can to have confidence in your design from the beginning?

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7 Ways to Protect Against Gasket Blowouts

The fall guy…defined by the Urban Dictionary as “a person who is left with the blame for a crime, regardless of whether they were involved or not”. In our world, the fall guy is the lowly gasket. Too many times, gaskets tend to be an afterthought in the design process, BUT the gasket (or the material) is the first to be blamed if there are ever any problems in the application. If you are currently designing (or may ever design) an application that has gasketed joints, or are currently in the middle of troubleshooting (or may ever troubleshoot) because of a leak in a joint, this week’s post is for you!

Over the years, we have just about seen it all. We’ve been a part of varying stages of design projects….at times we’ve almost been a part of the design team, lending our expertise to help ensure success once the gasket is cut, and other times we come in at the tail end to suggest a material that will meet your exact specifications. We’ve also been the firefighters…driving in on our big red truck with hoses spraying (ok, not really…) to offer a gasket material solution when everything else you’ve tried isn’t working. Blame it on the design of the joint, blame it on the design of the gasket, blame it on the material, blame it on the rain….regardless, there are potential problems lurking everywhere and we’re here to help you navigate some of those issues. Everyone’s time (and money) is valuable and we want you to be educated and aware of what can be done to minimize your chances of a gasket blowout.

What You Need To Know

Protecting your product launch and the application from the damage a gasket blowout can cause is your #1 priority in design (or redesign). Nobody wants a gasket to be the reason a project can’t launch as planned. Like we mentioned above, your gasket may be the culprit, but the issue might also be something else entirely. Here are 7 things to consider to help protect your application from gasket blowouts.

  1. Material choice: Designers must use caution to select a material that is suited for the operating conditions, including temperature, pressure, fluid resistance, durability (for handling), durability (in service), aging characteristics, and other factors.
  2. Temperature: Consider the peak exposure, and choose material capable of withstanding that level of exposure.
  3. Pressure: Sealing joints that are holding back high pressure need to have a gasket with reinforcement to provide radial strength. Be sure to choose reinforced material for high pressure joints.
  4. Flange loading: Flanges are critical pieces of the bolted joint. Consideration must be given to: flange flatness, surface finish, stiffness, material (expansion), preparation, and others.
  5. Assembly: Joints must be assembled properly to recommended torque values and sequence. Often with compressible products, a second round of final torque once operating temperature has been achieved is also helpful to maintain load over long term service.
  6. Protection: Some gaskets exposed to extreme conditions can benefit by additional protection which shields the gasket body from destructive conditions. Heat flow, fluid erosion, and other “wear effects” can be protected against by flange rings, embossments, coatings, and other protective measures.
  7. Thickness: Generally speaking, the thinnest gasket you can use is the best choice. Thickness gets increased to compensate for flange conditions or other factors. Thinner gaskets have less chance for blowout than thick ones since the load is concentrated over less volume, providing higher shear strength to prevent blowout.

Go Forth

We love a good gasket blowout picture – send us yours and we just might feature it in an upcoming article.

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