Many car owners don’t realize that valves play an essential role. The sleeves on the valve prevent combustion gases from passing through them. When valves start to wear out, it can be easily detected if one knows the symptoms of bad valve seals.
So, to answer the question: “What are the symptoms of a bad valve seal?“, car owners need to know the definition of a car valve and its seal.
Definition of Valves and Valve Seals
The valve is the automotive part designed to help the engine run properly by closing and opening at the right time.
There are many valves that play different roles inside the automobile: the exhaust valve will transfer waste gases outward, while the intake valve allows the mixture into the cylinder.
And of course, valves are one of the most essential control elements in any system.
To support the valve, valve seals are created to control valve lubrication and oil consumption in different types of engines.
Furthermore, the seal located above the valves prevents the oil in the cover from being sucked into the engine. The seals, made from sturdy rubber, easily fit on top of the valve inside a small collar.
For this reason, the seal must be very well designed to ensure its performance.
How does the valve work?
Pear-shaped lobes, called cams, control the operation of the valves. Combined with a rotating shaft called a camshaft and crankshaft gears, the valves help control the exhaled smoke.
Inside the engine block where the camshaft is mounted, various small metal cylinder tappets are positioned above each cam.
From the tappets, a metal push rod reaches the cylinder head. The top of the push rod connects to a rocker arm. This part’s role is to bear against the valve stem.
This is when the overhead valve system works: when the push rod rises on the cam, it causes the rocker arm to pivot.
This action will push the valve down against the spring pressure. On the other hand, when the cam lobe rotates further, the valve spring moves and closes the valve.
The Main Symptoms of a Bad Valve Seal
Any problem with the car’s valve is serious, especially when it concerns the engine. So, what are the symptoms of a bad valve seal?
For your vehicle to operate at its maximum capacity, valves with proper seals are essential. Any problem with the seal or the valve means you will need to rebuild the car’s engine to get it back into working condition.
Pay attention to the information below to know the symptoms of valve stem seals in your car. You can also browse online for the best maintenance tips for your car’s engine valve.
1. Ticking/Popping Noise
When it comes to problems with your car’s valve, a ticking or popping noise is the first to make its presence felt. Sometimes, you might notice these issues occur before any other problem.
When you accelerate the engine, the noise becomes louder. This means that some valve components are misaligned or worn out. The last reason could be that the car’s engine is not receiving enough lubrication.
The majority of cars are equipped with hydraulic tappets. These require continuous lubrication and constant pressure.
If the pressure decreases a bit, it would increase the excessive movement of the valve train. Remember that ticking or popping noises are the first symptoms of a bad valve seal in your car.
2. Heavy Smoke Presence
High levels of smoke are the second sign of faulty valve seals. Drivers can see a lot of exhaust smoke when starting the car; however, too much smoke can be the result of deteriorating valve seals.
For this reason, it is recommended to check the valve seal when car owners detect waves of smoke.
3. Engine Power Loss
Another indicator of valve problems in your car is a decrease in engine power and performance. Car manufacturers design car valves to fit perfectly into their seats and minimize freedom of movement.
If the valve guides and seals are leaking, oil can accumulate on top of the valve and cause it to lose its seat or create a gap. This could further lead to compression problems, which would result in poor combustion and power loss.
Another issue is burnt valves, which are responsible for engine power problems. When a valve burns, it loses material and has large holes that vent gases and decrease the compression ratio.
The most common cause of burnt valves is leaking seals and guides. This can also include their failure to resolve a car compression problem.
When this problem combines with a cooling system or EGT (Exhaust Gas Recirculation) issue, the risks of a burnt valve increase.
This is another symptom of bad valve seals, which should not be ignored at any cost.
4. Perform the Cold Engine Test
A cold engine test is certainly the best way to answer the question of whether the valve seals are leaking.
If you leave a car unused for a long period or overnight, oil will remain on top of the valve cover head, and the next time you drive, the oil will eventually stick at the level of the bad seal and create blue smoke.
This test is the ultimate way to detect bad valve seals.
5. Perform an Engine Braking Test
Another test to spot the symptoms of bad valve seals is engine braking. In order to know if you have a worn valve seal or not, drivers can press the accelerator after coasting and the oil that remains on the front hood will burn.
6. Blue Smoke from the Exhaust Pipe
If you are looking for obvious symptoms of bad valve guides, blue smoke coming from the exhaust pipe is a sure sign that the car’s engine has a problem.
Although blue smoke is not the result of a problem with the car’s valve, it is a common indication.
When the valve guides and seals wear out, it allows oil to pass into the combustion chamber and be burned with the car’s fuel. Car owners will also notice that oil levels continue to drop or that they need to add oil more frequently.
Although the amount of blue smoke seen when the valve guide and seal fail is small and barely noticeable, if large amounts are present, you might have damaged piston rings.
7. Idle, Stop, Go Driving
Bad valve seals primarily manifest when the car is idling at stop lights. The reason for this symptom is that high levels of vacuum in the intake manifold occur when automobiles remain unused for long periods.
This leads to oil being sucked into the heads and collected at the valve stems.
With a bad valve seal, the oil will be drawn towards the valve guide, passing through the erosion area during acceleration.
Frequently Asked Questions
To better understand bad car valve seals, our automotive experts will help drivers answer the most common questions on these related topics:
What Causes Valve Seals to Deteriorate?
The main factor causing lower quality materials like nitrile to harden and become brittle is the high operating temperature.
When the seals deteriorate, they cannot control the oil slipping into the guide. Worn valve seals cause various problems such as cracks, decreased oil control,…
Will Bad Valve Seals Cause Low Compression?
Several valve problems can lead to low compression. There are several reasons for this issue.
The intake and exhaust air valves overheat, gas leaks, the valve seals deteriorate, and the gas cannot seal completely.
How Long Do Valve Seals Last?
150,000 miles under normal conditions. However, valve seals can deteriorate due to infrequent oil and filter changes, as well as poor installation.
How to Fix a Leaking Valve Seal?
Don’t panic when your car has a leaking valve seal. We are here to help. There are 3 ways to fix this problem.
- First, and in the simplest way, replace the leaking seal. You can simply remove the cover and scrape off any buildup stuck in that area.
- After that, position the new seal in place and remember to tighten the bolts.
- Drivers can add an oil leak stop additive to the engine.
This product’s role is to prolong the life of the valve seals by making them swell, which can stop a leak.
However, this is a temporary solution and drivers must take their car to the auto mechanic.
- Last but not least, it is recommended to use a high-mileage engine oil. This oil can keep the valve seals flexible to reduce corrosion.
By applying engine oil, seal conditioners can reduce or even stop leaks.
Summary
Thus, we hope this blog has helped you understand in detail the symptoms of bad valve seals. Remember that you should not modify any car part to fix the problem, but rather entrust it to an auto repair expert to resolve the issue.