If you own an older car, or one that’s completed more than 75,000 miles, then head gasket failure is one of those things that can happen at any time.
Thankfully, there are some signs that might give you a little warning that not is well inside your engine and give you time to repair early on. Within this guide, you will learn how to choose the best head gasket sealer.
What Is Head Gasket Failure?
On most engines, a thin gasket made up of steel or cork, is located between the cylinder head and main “block”. The head gaskets job is to seal this joint and stop water and oil getting into parts they shouldn’t
When the gasket fails, this means that coolant water can get into the lubricating oil of the car, and also oil / water getting into the combustion chamber, where the fuel and air combust to create momentum.
Things that can cause this type of failure are the general age of the motor, a history of overheating which can warp the cylinder head and lack of regular maintenance.
By far the best cure for head gasket failure is regular serving and check-ups by your local mechanic to prevent problems before they become roadside breakdowns.
Common Symptoms Of Possible Head Gasket Failure
• A white / yellow mixture inside the oil filler cap – This is often referred to as “mayonnaise” as it really does ape the look of it. Be careful though, because an engine that receives little use can display mayonnaise due to condensation within the cap. This is nothing to worry about, although you may want to drive your motor more often to avoid parts seizing up through lack of use.
• Flat spots whilst driving – This can often be a sign of poor timing or issues within your fuel system, yet it can also be a sign that water / oil is getting into the combustion chamber, occasionally getting in the way of ignition.
• White smoke from the exhaust – Most cars have this when starting up early in the morning, due to condensation in the exhaust pipe drying out and is nothing to worry about. However, if your warmed up car still displays white smoke after 15 minutes driving, then water could be making its way from the coolant system into the combustion chamber.
• Blue smoke from the exhaust – This is often a sign of piston ring wear, especially in older cars with more than 100,000 miles on the clock. In this case it’s not an immediate breakdown threat, although you should have the ring fixed when you can. However, if you spot blue smoke plus a white mayonnaise inside your oil cap, it can be a sign oil is entering the combustion chamber and being detonated. The blue smoke is basically the result of a dirty fuel (Engine Oil) being burnt instead of petrol.
• Occasional uneven engine tick-over – Head gaskets don’t always “fail” straight away. Often, they fail in one small section of the gasket, causing slight symptoms that can come and go over time. Things to watch out for are uneven running on specific parts of the rev range, plus white smoke that may only occur on tick-over or at certain speeds. This happens because the head gasket might only be failing within one section, effecting a specific cylinder chamber or only weeping when the momentum of the car “warps” the cylinder head in a particular way.
How To Fix It
There are a few ways to fix a cylinder head gasket failure when it happens.
• Re-torque the head bolts – Sometimes a poor mechanic might never have tightened the cylinder head bolts properly. Re-tightening them with a quality torque wrench could cure the issue easily.
• Change the head gasket – Quite a time consuming operation and one that many home DIY mechanics might feel beyond their capability, particularly if you need to dismantle a time belt / chain system to remove the head properly.
• Head gasket sealer – No visit to the repair shop and no expensive bills to partially dismantle and fix your car.
What Is Head Gasket Sealer?
Head gasket sealant is a simple 30-minute fix that most DIY mechanics can complete easily. By pouring it into the radiator cap, it can flow through the coolant system until it discovers the leak. By sealing the leak up you can continue driving your car without heavy mechanical work required.
It’s quick. Your car can literally be fixed within the hour, keeping it on the road if it’s your only vehicle or you need it to run a business. Once fixed, most cars go on to lead happy and reliable lives. It’s especially helpful if you own a vehicle that’s entering the latter stages of its useful life and expensive repair bills just aren’t economically viable.
Best Head Gasket Sealers – Our Reviews
There are two products which most mechanics agree are the best head gasket sealers. Blue Devil and Bar’s Leak.
1. Blue Devil Head Gasket Sealer (The Best Choice)
We tested Blue Devil Gasket Sealer on my fathers Toyota Corolla that was just beginning to show the first signs of head gasket failure. The typical mayonnaise found on the oil cap was the main symptom, although it had yet to start smoking badly from the rear.
The good thing about Blue Devil, is the fact it doesn’t contain particles within the solution. This means your water pump and seals won’t suffer wear, making this fix one for the long term.
Adding the sealer to the coolant system was reasonably easy. We started by completely dropping the existing water, topping it back up again and running the car for 10 minutes. This ensured the coolant system was completely flushed through and clean.
On the second top-up, we did two things:
• Add the Blue Devil Sealant.
• Disconnect the thermostat.
The reason we disconnected the thermostat, was to ensure the fluid got everywhere within the engine. We didn’t want the thermostat diverting the fluid from where it needed to go.
All in all, it took about 120 minutes to install the fluid. This is amazingly quick considering the strip down that might be needed if you changed the entire gasket!
Did It Work?
It’s been 3 months and 5000 miles since the Blue Devil was added to the coolant system.
• No more mayonnaise in oil filler.
• No flat spots whilst driving.
• Spark plugs look clean with no oil / mayonnaise covering.
So far, the Blue Devil has been a complete success and even after some heavy interstate driving the repair appears to be rock solid and ready to tackle another 50k miles without any issues.
Does exactly as it says on the bottle! Our only advise would be to thoroughly flush your coolant system and take your time installing the fluid properly. This way you know the repair is going to stand the test of time. Click Here to Check Out The Blue Devil on Amazon!
2. Bar’s Leak Head Gasket Sealer
The Bar’s Leak Head gasket sealant was one I’ve been wanted to test for a while as it claims to cure cracked cylinder heads too. We have a 1999 Ford Falcon in the garage that’s been off the road due to a slightly cracked head, this seemed the perfect opportunity to see if Bars Gasket Sealer could help us out!
Just as we did with my fathers Toyota, we drained the existing coolant. This time around however, we weren’t able to flush it through completely as the leak was bad enough to cause major damage if we started it right up.
Instead, we drained the water as good as we could and topped it back up including the Bars Sealant. Once again we took the thermostat off and made sure the spark plugs and ignition were ready to fire.
We started the engine on the second go, not too bad for a car that had been sitting for 9 months! For the first minute, a flurry of white smoking poured out the back, yet soon enough something amazing happened. It’s stopped!
Once the smoke cleared, the engine revs became more consistent and our little Ford slowed to a nice, sweet tick-over speed. At this point we let the engine warm up for 15 minutes and help the Bar Gasket Sealer perform the rest of its work.
To complete the job, we changed the engine oil, filter and generally got the Falcon serviced and ready for its new lease of life.
Did It Work?
As with the Toyota, we let the Falcon pass the 5000-mile mark before making comment. This car has been used for garage part deliveries so it only took a few weeks.
What we can say is so far, so good. The repair has held and we even managed to perform a slight water change, adding some anti-freeze to ensure the cylinder head didn’t worsen over the winter period.
As the engine stands now, it runs sweetly, no mayonnaise on the filler and everything appears perfect! We also managed to save a few thousand Dollars by keeping an older vehicle on the road instead of purchasing a brand new van.
Worked wonders on our Ford Falcon’s cracked cylinder head and will obviously perform the same task on a blown gasket too. It has kept a previously “scrapped” vehicle on the road for a bit longer, which is always a great thing for the bank balance! Click Here to Check Out The Bar’s Leak on Amazon!
Best Head Gasket Sealers – Comparison Table