Summary
A cylinder head sits atop an engine block and covers its cylinders, creating the combustion chamber. The cylinder head, which is held in place by the head gasket, makes room for the tubes that provide fuel and air to the cylinders.
A cracked cylinder head will result in oil or coolant leaks and will highly affect the engine’s compression. The leakage will leave oil dumped in the cylinder which will then spoil the spark plugs. Also, the air and fuel in the combustion chamber mixture fail to ignite, and the engine misfires.
The cracked cylinder head is frequently misdiagnosed as a blown head gasket by DIYers and even some professionals. The error is simple to make because many of the symptoms of the two issues are similar.
You’ll notice the following symptoms of a cracked cylinder head: overheated engine, low level of coolant, exhaust pipe steaming white smoke, water pump failure, faulty thermostat, coolant leak, misfiring and uneven running, oil-coolant intermix, warning lights on, and combustion gases in the cooling system.
Now, let’s go deep to explain the ten possible symptoms of a cracked cylinder head and their causes!
Contents
Overheated engine
Coolant may enter the combustion chamber through a cracked cylinder head instead of flowing through the engine as intended. As a result, the engine can begin to overheat.
Low Level of Coolant
You might observe that the coolant level starts to decline if the cylinder head crack allows coolant to enter (and be burned) inside the combustion chamber.
Exhaust Pipe Steaming White Smoke
The cylinder head has coolant tubes that go through it. A head crack can let coolant from those tubes leak into the engine’s combustion chamber, where it burns when the engine is burning. As a result, the vehicle’s exhaust will emit what appears to be white smoke but is actually steam. The lovely fragrance of the exhaust fumes may also catch your attention.
Water Pump Failure
If the water pump breaks down, the coolant will not be able to circulate properly in the engine. Even though it may be nice and chilly in the radiator, the coolant around the water jackets in the head and block will be very hot. Coolant can only move through natural convection in the absence of a pump, and this process moves far too slowly to remove more heat before the engine overheats. If you are unsure of the date that your car’s water pump was last serviced, look online for Reading garages and make a water pump replacement appointment as soon as you can.
Faulty thermostat
At the operating temperature for which they were designed, combustion engines perform at their peak efficiency. Engines typically operate between 190- and 210-degrees Fahrenheit, or 85 and 99 degrees Celsius, which is hot enough to scald you. The fuel consumption, emissions, and wear of an engine increase when its operating temperature is lowered.
To find out if a prior MOT test failed due to excessive emissions, use an online MOT history checker. A thermostat stops coolant from evaporating from the radiator until the engine coolant reaches the appropriate temperature. Once the engine reaches the desired temperature, the thermostat opens, letting coolant at room temperature cool it down until the thermostat gets cold enough to close.
The cycle continues as the engine runs. If the thermostat is stuck open, your car will probably run extremely cold. This is because the radiator never has a chance to fully warm up because it receives a steady flow of coolant from the entire system. If the thermostat is jammed closed, your engine will overheat rather quickly.
The hot coolant has nowhere to go to cool off. On some engines, the heater can be briefly used as a small radiator. The efficiency of this technology is influenced by the size of the heater core and the placement of the cooling system.
Coolant Leak
If too much coolant seeps out over time, you won’t have enough to keep the engine cool enough. However, it’s a good idea to regularly check the radiator and overflow reservoir to make sure you have enough coolant because you can lose a significant amount of liquid before overheating.
If you think there might be a coolant leak, checking your radiator cap is a great idea. It’s a cheap part, but if it malfunctions, it might have serious implications. Keep in mind that not all coolant leaks are visible. Small cylinder head cracks can occasionally go unnoticed for a while, but in more severe cases, the symptoms will be quite obvious.
Misfiring and Uneven Running
Three factors are required for a full-combustion engine: a good spark, the right air/fuel ratio, and sufficient compression. Loss of compression from a broken cylinder head can make the engine run rough and misfire.
Oil-Coolant Intermix
Coolant and oil may occasionally mix as a result of a broken cylinder head. Some 1.9L single overhead camshaft Saturn vehicles are notorious for developing damaged cylinder heads, which results in coolant-oil mixing.
Warning Lights On
The check engine light, low coolant level light, and engine over-temperature light can all be set off by a broken cylinder head. You might also notice it starts to rise if your automobile has a temperature gauge.
Combustion Gases in the Cooling System
The cooling system may become contaminated by combustion gases due to a broken cylinder head. As a result, the coolant may have an excessive number of bubbles before it starts to boil. You might also notice that there is a lot of pressure on the cooling system.
Causes of Cracked Cylinder Head
Some cylinder heads, like those on a Saturn engine, are susceptible to cracking as a result of design defects. But engine overheating is typically the cause of the issue. Thermal stress causes the cylinder head to shatter when an engine runs too hot. Even one instance of engine overheating might lead to a broken cylinder head.
The most frequent cause of cylinder head failure is overheating, which can be brought on by coolant loss, head gasket failure, or restricted coolant flow, among other things. In extreme circumstances, a cracked or broken cylinder head might cause total engine destruction! To try to stop this from happening, you must address any issues as soon as you can.
Furthermore, cylinder heads are subject to great pressure from abrupt temperature changes, which can cause them to deform. This indicates that it no longer provides a flat surface to maintain the head gasket in the proper position, which can cause costly issues down the road that require significant repairs or engine replacement in its entirety.
A particular issue with aluminium cylinder heads is warping. Different engines have varying amounts of cylinder head warping tolerance; some may endure significant warping while still performing well. If your cylinder head does warp, you might be able to take it to a mechanic who has experience realigning them; if not, you’ll probably need to get a new one.
How much does it cost to fix a cracked cylinder head?
Cylinder head repairs are typically a thing of the past. Nowadays, almost all shops will replace a cracked head rather than attempt a repair because the majority of new heads are constructed of aluminum. You should typically budget between $1000 and $2,500 per cylinder head if you decide to have a professional replace them in your car.
The precise cost will, of course, vary depending on a number of variables, including the year, make, and model of your car. It’s also important to bear in mind that occasionally, extra damage to other engine components results from a cracked cylinder head. You’ll most likely need to repair or replace the engine entirely in this situation.
Related Article
- How to Test a Blown Head Gasket
- Understanding automobile cylinder block
- Car Engine Cylinder Configurations
- Understanding Cam Phaser
- Components of internal combustion engine
- Why is water coming out of my exhaust pipe
Are you a mechanically inclined DIYer? Then this video will really help you to fix a cracked cylinder head:
Bottom Line
Different cylinder head failure signs exist, thus it’s critical for drivers to be able to identify them as soon as possible in order to limit damage. The engine (and ultimately the car) will fail if the cylinder head malfunctions.
That is all for this article, where the symptoms and causes of a cracked cylinder head is discussed. I hope it was helpful, if so, kindly share with others. Thanks for reading, see you around!