If you find yourself asking, “can you drive with a blown head gasket?” it either means you already have a blown head gasket or are driving a car prone to blowing head gaskets.
If your situation is the latter, there are preventive measures you can take to keep this from happening, which we’ll discuss further in a later section.
Can you drive with a blown head gasket?
Now let me help you to answer the question, first we’ll go over head gasket basics before we go head on the question.
What is a head gasket?
A head gasket is a gasket that fits between your car's engine block and cylinder head. It keeps compressed air and fuel inside the combustion chamber, allowing the mixture to be ignited and turned into energy. A head gasket also prevents oil or coolant from leaking into the combustion chamber.
All modern automobiles have a head gasket, but they vary in thickness and construction depending on the manufacturer's engine design.
Given the functions of a head gasket, blowing it would cause various problems because you'd be driving a car whose engine fluids and gases aren't where they should be. For instance, a blown head gasket can allow coolant to flow into the cylinders, exhaust gases to get into the coolant, coolant to seep into the oil, and so forth. As will be illustrated in the next section, such incidents can prove to be quite dangerous.
Problems Caused by a Blown Head Gasket
Coolant leaking into the combustion chamber can lead to various problems. For starters, it can foul spark plugs and cause poor engine performance due to the coolant deposits left from combustion. Secondly, it can alter the air-fuel ratio and cause the sensor to fail. Finally, having coolant in the combustion space can cause the piston, piston ring, and cylinder wall to rust, lowering compression and necessitating an engine rebuild.
Additionally, if coolant gets into your cylinders, it could mix with engine oil, compromising the oil's ability to lubricate properly. And since significant engine parts such as the main bearings, valve train, and crankcase require lubrication, insufficient lubrication could cause bearing damage and total engine failure. An external oil leak has the same impact since it leads to low engine oil.
A blown head gasket could also result in combustion gases leaking out of the combustion chamber, which can cause extremely high pressure in your car's cooling system. These hot gases could also damage metals in the surrounding area.
Coolant could also leak externally, which could cause the engine to overheat whenever you drive and possibly damage it. The leaking coolant is usually hot, so it could burn you as you check under the hood. It also puts your car at risk of catching fire.
Although some cars will stop immediately when the head gasket blows, some can tolerate the resulting damage for a few months. But given the dangers it poses, driving with a blown head gasket is not worth the risk. So, for safety reasons, we recommend either repairing the leak or replacing the head gasket immediately.
How to Tell if a Head Gasket is Blown: Blown head gasket symptoms
The signs of a blown head gasket include:
- Coolant leaking externally from your engine. The leak usually happens just below the intake or exhaust manifold and is more noticeable when the engine is warmed up. It appears as steam spraying out of the motor.
- Engine constantly overheating. Loss of coolant from an external leak causes the engine to overheat when the car is driven for any length of time. Overheating could damage the engine necessitating an engine rebuild.
- Sweet smelling, white smoke coming from the exhaust pipe. A head gasket leak could also be internal, with coolant flowing into the combustion chamber. Combustion then causes it to evaporate and appear as white smoke, which has a sweet smell and continues even when the engine is warm.
- Bubbles in the radiator. An internal head gasket leak also causes exhaust gases to enter the cooling passage, creating bubbles in the radiator or coolant reservoir. You can perform a DIY chemical test on your coolant to check for the presence of exhaust gases. The test kit (B000NPDL76) is available in most parts stores and is the most effective way to test for a blown head gasket.
- Oil turning milky white. If the internal leak is large enough, the coolant will seep past the piston rings into the oil. When water mixes with oil, it causes the oil to appear milky white. You can check for this by looking at your oil dipstick or looking under your oil cap.
Preventing a Head Gasket from Blowing
Due to its function, a head gasket is regularly exposed to high pressure and excessive fluctuations in temperature. These intense conditions are what usually cause a head gasket to blow.
All internal combustion engines do, however, require high pressure in the combustion chamber. Fortunately, head gaskets are designed to withstand this pressure at all times. The problem comes when the pressure levels rise higher than they should. Excessive pressure in the combustion chamber can be brought on by:
- Knocking or pre-ignition. To prevent either of these occurrences, ensure you set your ignition timing as specified by the engine manufacturer and that your car's fuel system is clean. (B00092893E)
- An unusually high compression ratio. A buildup of carbon deposits reduces the size of the combustion chamber and consequently causes an increased compression ratio. To prevent an excess carbon buildup, ensure you regularly add a fuel system cleaner to your car's gas tank.
- High intake manifold pressure. If you have a car with a forced induction engine, like a turbocharger or supercharger, ensure the pressure regulating systems are operating correctly.
As mentioned earlier, extreme temperatures also contribute to head gaskets blowing. And while head gaskets are designed to consistently withstand the high temperatures of combustion, abnormally high temperatures can damage them.
When exposed to excessive temperatures, the metal parts of your engine expand and contract, causing space between them that become leaks in the head gasket. To keep the temperatures in your engine in check, ensure your cooling system is properly functioning and check your car's coolant level regularly. (B0002KO112)
Now, should you find yourself with a blown head gasket, expect high repair costs due to the amount of work needed to disassemble and rebuild an engine. Alternatively, you can also use a head gasket sealer (B003RGIWO0) to seal the leak. This is an option worth considering since head gasket sealers cost less, are easy to use, and work quickly, so you should be back on the road soon.
How Much Does a Head Gasket Repair Cost?
A head gasket repair is estimated to cost between $1000 and $2000.
The cost of repairing a head gasket varies significantly from car to car due to various factors including:
- Type of cylinder head
- Number of cylinder banks
- Damage to the engine block or cylinder head
- Additional component replacements
You will rarely find a single head gasket costing over $100, and the majority cost way less. Most of the cost of a head gasket repair is due to the labor and expertise involved. The more complex the job is, the higher the cost.
For example, six-cylinder and eight-cylinder engines in a V configuration have two head gaskets, one on each side. Replacing one requires the other one to be replaced as well to ensure the engine remains balanced. Additionally, a majority of the engine is taken apart to access the head gaskets. Therefore, the cost of head gasket replacement in a V-style engine or boxer engine can be double or triple.
TIP: Given the labor associated with the replacement job, it is cost-effective to have both head gaskets replaced at the same time.
Additional damage caused by the head gasket leaking can also significantly increase the cost of a head gasket repair job. One of the functions of a head gasket is to retain the high temperatures and pressures of combustion, but if the engine block and cylinder head are damaged, a head gasket, even if fixed or replaced, will not be able to seal the combustion chamber properly.
Therefore, if the cylinder head is warped, cracked, or dented, it will also need to be straightened, fixed, or replaced. The same goes for the engine block. And considering the auto shops that do this kind of work are usually specialty shops, their prices can be incredibly high. If there are any additional damages, you will need to dig deeper into your pockets, especially if the engine block is beyond repair.
Repairing a blown head gasket is considered to be one of the most expensive car repairs. As mentioned earlier, you can avoid these costs by using a head gasket sealer that effectively seals leaks in blown head gaskets.
Conclusion
Most head gaskets don't just blow without warning, but instead, start as a small leak. It is, therefore, important to watch for the signs of a blown head gasket so you can catch leaks early and repair them in a timely manner. Doing so will reduce the repair cost and protect the car from further damage that would arise from a blown head gasket.
You should also do routine maintenance on your car, as it is an effective preventative measure against blowing a head gasket. Should your head gasket blow, have it repaired as soon as possible and do not drive your car before then. Driving with a blown head gasket could eventually lead to total engine failure.
I hope you found the answer to your question” can you drive with a blown head gasket”.
If you liked this article make sure to check out: how much does a car weigh and What to Do After Buying a Used Car
