A head gasket performs a range of functions in a car, and it’s not always easy to figure out when your head gasket is blown. Learning the signs and symptoms is important to reduce the risk of further damage to your car.
A blown head gasket can cause your engine to overheat, mixing of engine oil and coolant, white smoke emitting from the exhaust, sudden loss of power, and coolant leak. If you see any of these signs, it’s time to have your car looked at by an auto professional right away.
There are a lot of concerning symptoms of a blown head gasket, but it can quite easily slip under the radar for quite a while if you’re not on the lookout for the common signs. The rest of this article will go over the signs of a blown head gasket and let you know what to do about it.
What Is a Blown Head Gasket?
The head gasket is primarily responsible for sealing the connection between the cylinder head and the engine block, particularly the oil return passage, pistons, cylinders, and coolant passage. A head gasket is referred to as ‘blown’ if the gasket fails to seal due to thermal pressure when the engine overheats.
The adhesive between the cylinder head and the engine block breaks, resulting in coolant leaks, oil leaks, and gasses from the combustion chamber. Naturally, the improper separation of oil and coolant results in damage to the engine and is a serious problem that needs addressing quickly.
How to Spot a Blown Head Gasket
A blown head gasket isn’t always easy to diagnose since the signs are often similar to other engine problems such as overheating. There are, however, a combination of factors that can let you know when your head gasket is blown and needs repairing or replacing at a certified mechanic shop.
You will not be experiencing shaking of any kind while driving, or squeaking sounds coming from the engine, or pulling to the right or to the left as you drive. It will at first be unnoticeable but then you will start noticing more smoke coming out the tail pipe and all the symptoms listed below.
First and foremost, if your head gasket isn’t able to properly manage the exchange of liquids from the cylinder head to the engine, the engine won’t be getting enough coolant (or getting an improper mixture of coolant and oil), leading to an overheat. The hot combustion gasses will leak into the cooling system, burning the coolant in the process.
White smoke coming from the exhaust is a telltale sign that you have a blown head gasket. The smoke will smell sweet because it is a combination of oil and coolant that has been burned into steam after the gasket has leaked.
Sometimes, this smoke might be blue to reflect a leak from the oil passage into the cylinder, but blue smoke can also be a cause for some other car issues.
Oil contamination is a sure sign of a blown head gasket. The head gasket isn’t supposed to allow the coolant and oil to interact at all, but with a blown head gasket, the leak will allow the two to mix, causing problems for your engine.
This often results in a frothy mixture that you can observe under the oil cap. Similarly, if the oil is contaminating the coolant, then you may also see a film on the radiator cap that is white in color.
A head gasket is responsible for helping the engine run properly, so if the head gasket is blown, it naturally follows that the engine’s performance will suffer. Loss of power is natural in the event of a head gasket failure, and you may notice that your engine isn’t as responsive and that it idles roughly.
Coolant or oil leaks are quite common and strong indicators that something is wrong with your head gasket. External leaks are not necessarily something to be alarmed about, but you should get them fixed right away so that your engine doesn’t overheat from a lack of coolant.
Why You Should Never Ignore Head Gasket Problems
If you’re concerned that your car has a blown head gasket, you should be on the lookout for your engine overheating, contamination, or smoke emitting from your exhaust. If you catch the problem early, you might be able to get it repaired for less using sealants.
On the other hand, if you need a head gasket replacement, you’ll be looking at a much higher bill. Even so, you should still invest in the future of your car because the alternative—leaving your blown head gasket—is much worse. There are numerous issues that may arise from leaving a blown head gasket.
- Ruining your engine
- Damage to the hoses
- Damaging your catalytic converter
- Ruining the cooling system
- Damaging the radiator
These issues will cost you a lot more money that just replacing your blown head gasket, so make sure you get a quote from your auto shop as soon as you start to suspect an issue.
How Much Does It Usually Cost To Fix A Blown Head Gasket?
When you have a blown head gasket, you have a major problem on your hands. This repair is not something quick and easy. The mechanic will need to take the top of your engine apart and remove the head(s) to get to the gaskets and replace them.
The problem is that usually if your head gasket issues are not caught in time the engine can overheat and this most likely will warp the heads. This will require machining the heads to get them to be straight again so they can sit tightly on the engine block.
All this work is, well, a lot of work. You can expect to spend from $1000 and up to $3000 depending on how bad the damage got.
Some do-it-yourself-ers will think about repairing this one in their garage, and that is cool, but most people just don’t have the necessary tools that are required for most repair jobs of this caliber. Although you will save a lot if you do this repair yourself, this one requires a higher level if experience to get it done successfully.
Does Blown Head Gasket Ruin Engine?
A blown head gasket does not always ruin the engine but it does usually require a lot of work to get the engine back on the road. It is a major repair and can cost a few thousand dollars.
The engine block is very strong but the heads are usually made of aluminum which is not as strong as cast iron block. If the heads warp from over heating they can always be machined and straightened back out.
Fortunately it is not the end of the world if you have a blown head gasket, it is repairable.
Is A Blown Head Gasket Repairable?
The head gasket is usually made of some composite material reinforced with steel bezel, or some times it is made from multi-layer sheet steel clamped together. Once this gasket is blown it usually is destroyed. A part of it is completely ripped through.
A blown head gasket will always have to be replaced with a new one.
When you have a blown head gasket, saving money on a head gasket will be your last concern because the work it takes to get to the gasket to replace it is where the bulk of the cost will be.
What Causes A Head Gasket To Fail?
There are many reasons a head gasket can fail and it is not a normal thing for this to happen. This usually happens under extreme conditions so it is not something you should worry about unless you are really abusing your truck.
Lack of regular maintenance will cause you to not check the level of your coolant in the truck. If it is neglected, the coolant may be leaking from somewhere, even with a small leak. This will cause the engine to overheat and that will cause a blown gasket.
If the heads are not tightened to the manufacturer’s specifications and the gasket is not squeezed properly, it can blow out from exhaust pressure constantly trying to escape through a tiny gap and finally giving out and blowing a hole through the side of it.
How Do You Check A Head Gasket?
Checking if your head gasket is ok is not something one does as part of a regular maintenance of a car. A mechanic in a shop might do that just to make sure they catch a problem, but it is not something a regular truck owner needs to worry about, normally.
The easiest way to check if your head gasket is ok is to open up the oil cap and look inside and under the cap. If you see nothing, or just amber oil in there then everything is fine.
You will have a problem on your hands if you see milky whitish foamy substance there. This means that the coolant has been mixing with oil inside the engine and the most common way for the coolant to make its way into the oil is through a failed head gasket.
How Far Can You Drive With A Blown Head Gasket?
If you are in an emergency, drive as far as your car will drive. Otherwise, if you have other options, stop and don’t drive any more until the head gasket is repaired.
If you let the engine cool down, you can drive a little ways until the engine heats up again and then you have to turn the engine off again. This is highly not recommended but if you are in a situation that you have to drive, this is the best way to keep the engine from being destroyed.
When the head gasket is blown, the coolant will most likely be leaking into the cylinders and the engine oil, so the oil will loose its intended performance factors and also you will be loosing lots of coolant as it will be burning up and going out the tail pipe. This will prevent the engine from cooling properly and an over heated engine is a bad thing.
Just don’t drive it if you have a blown head gasket. Get it towed to a mechanic and let them fix it.
Preventing Head Gasket Problems
A head gasket can be a major headache to deal with, but if you are prudent in your maintenance schedule, then you can reduce the risk of a major failure and prolong its life. Always stick to the servicing schedule as recommended by your manufacturer so that all parts of your car are working as intended.
Get your car checked out right away if you start to suspect a leaky head gasket. Professional advice is always helpful when it comes to the long-term health of your car, and with something as important as a head gasket, it’s important that you have someone experienced to diagnose the problem and suggest a potential solution.
A blown head gasket can be a big deal for a car owner, but the most important thing to remember is that you should have your car checked out by a certified mechanic as soon as you suspect that something is amiss with your head gasket.
You have good reason to suspect this if you’re seeing white smoke coming from your exhaust, your engine overheats, or you have leaking coolant coming from your car.
Valik loves tinkering in the garage and is currently restoring a 2000 GMC Sierra 1500 truck. He also writes about the progress on this blog. When not in the garage, Valik is also a web developer and a blogger. I know, strange, a hand in two completely different worlds. And that is the way he likes to keep it.