Many factors can become the broken valve spring cause. If you can identify them, you will easily determine whether any other parts are damaged due to valve spring failure.
However, the most important thing is that you need to know the signs of this problem. Because without diagnosis or thorough examination, you can’t get down to the root.
The next sections can help you. Scroll down for more helpful information and learn how to check it!
Valve Spring In Your Vehicle
What Does It Do?
Its function in your car’s engine may be relatively obvious, but these springs are also part and parcel in car engineering.
This one is a crucial yet underrated component of the valve train. Until the cam opens its seal, this part maintains the valves tightly closed against their seats.
Your valve will then be released, giving it springtime to work before the cam retracts it into the valve head.
How Does It Work?
A retainer holds this part in place while wrapped around the stem. Its principal responsibility is to regulate the entire valvetrain and ensure that the correct spring pressure amount is consistently provided to avoid it bouncing.
These springs play an important role since bouncing can result in power loss, total engine failure, and even breakage.
A pressure valve spring also aids in preventing valve float, which is when the engine’s speed exceeds its capacity and a disconnect occurs between the camshaft and the valvetrain.
The engine’ springs protect the axle, pistons, cylinder walls, and bearings because they close them completely and ensure the right amount of compression.
Additionally, they prevent hydraulic lifter issues by opposing the internal piston’s oil pressure and keeping the lifters from rising.
Type Of Valve Spring
The two main types of valve springs are single and dual designs, each coming with several variations. The single spring supports this part only; the double contains a second, smaller spring inserted inside the first.
The amount of pressure that each valve spring applies to the cam and valve is the other major distinction between them. Selecting the one with the proper spring pressure helps avoid “valve float” and high cam wear.
Its valve also has keepers and retainers as additional components. They are in charge of maintaining its tight connection to the valve.
Broken Valve Spring Cause: Causes & Common Symptoms
What are the most common causes of broken valve springs? Many reasons lead to this situation, but wear and tear on the spring, overloading it, and external impacts like accidents are the main culprits.
Common Causes
Similar to any component on a vehicle, the springs will show signs of weakening after a period of use and lose their original performance. This is a matter of natural wear and tear, and it is completely understandable.
That’s why I recommend that you check this part during regular servicing of your vehicle. Depending on your use, its lifespan may be longer or shorter than the average 30,000 miles.
The second and less common reason is overload. Depending on the type of valve spring, their loading capacity will be different. When the weight exceeds this level, the spring may break.
Damage caused by other components or by accidents should also be mentioned. Imagine your car is hit hard by an external force; it will damage internal components, including springs.
To fix it immediately and avoid major damage, you need to know what broken valve symptoms are. I used to encounter a slight shaking in the cover, and misfires might also happen at higher RPM.
For more detailed ones, check the next sections!
Symptoms
Backfire & Misfire
Can a broken valve spring cause a misfire? Yes!
The only inevitable sign of a broken part is misfires and backfires. The air-fuel combination will remain in the intake and exhaust system at the moment the spark plug fires when the valve spring snaps.
That implies that a backfire is audible from the exhaust system and the intake. Backfires and misfires, however, are ill-defined symptoms that can’t accurately diagnose anything.
Rattling
Most people will hear the rattling in its cover. A spring component that broke off and is now bouncing around on the cylinder head will generate the rattling. This might even lead to cylinder wall damage if left unattended.
However, when the spring breaks into two pieces, that is not always the case. So once more, slight rattling is not a telltale of the broken valve spring sound.
Knocking Sound
Leaving the engine running with a broken or bad valve spring is the shortest way to its self-destruction, giving off a deafening knocking sound that you can’t turn a blind eye to.
This is because the valve has fallen into the car’s cylinder, and it creates a banging noise when the piston slams it on the head of the cylinder.
Thus, if you hear any knocking noises, shut off the engine immediately and don’t start until you’ve inspected it.
Rough Running Engine
An engine with weak valve spring symptoms will run the worst at idle speeds. In that situation, the engine is likely to backfire, tremble, and make a weird sound that resembles an air pump.
If you have two or more of these symptoms, you can be sure that the spring is to blame.
Tapping Sound
Don’t ignore the tapping sound; it can be a sign of your weak valve spring.
A broken hydraulic lifter or a loose rocker arm will make a characteristic tapping noise. However, if it breaks in a way that slightly lowers the valve, you will hear a tapping sound.
Because of the space between the two, the tapping is brought on by the camshaft lobe striking the valve. The tapping, however, will originate from a single location in its cover when a single spring snaps, making it somewhat obvious.
Check Engine Light
Finally, I also notice the check engine light coming on in some cases. But using an OBD2 reader to diagnose a broken part is nearly impossible.
At this point, the misfire codes will appear again, as no procedures designate it. Nevertheless, depending on the error code, you can identify which cylinder has a damaged one.
How Does Broken Valve Spring Affect Your Engine?
Can broken valve spring cause low compression or seriously affect other parts?
Yes, it can result in various drivability and performance issues. The broken part will take a toll on the internal engine by causing compression loss, excessive noise, and internal engine damage.
The most disastrous aftermath is not always the actual shattering of them. The most devastating engine damage is caused by what happens after the breaking.
Once a spring breaks, it creates a gap through which the valve finds its way to the cylinder and is banged by the piston. Its stem locks or keepers could also open, facilitating its way to the cylinder.
Then, this seriously harms the piston, cylinder head, and other components nearby.
If you catch the problem early and replace it with a new spring, it will not cause serious effects. That’s why regular testing is highly recommended.
How To Check The Engine When You Have Broken Valve Springs?
A compression tester can be of great help in identifying a broken spring. All cylinders normally show low compression when the piston rings wear out or the cylinder head gasket bursts.
Your affected cylinder will be the only one that doesn’t have proper compression when this part breaks. The cylinder damaged by the spring will have zero compression.
You can almost be certain it’s a broken valve spring because nearly no other problems give such a result.
Investing in a compression testing tool is worth considering if you have more than one car or want to perform this task frequently. Or you can also do it periodically along with the general inspection of the vehicle.
How Much To Replace The Valve Spring?
People will not repair it when they face broken valve symptoms but mostly replace it with a new one. The repair does not guarantee long-term use or restore its original performance and efficiency.
And now, you need to pay more attention to the broken valve spring repair cost.
V Configuration Engine
It takes a long time to replace an engine’s 5.3 broken valve spring with a V configuration (V6, V8). Let’s use the Nissan VQ35DE engine as an illustration.
It would take a skilled mechanic 12 to 14 hours to replace new ones in this engine. And the cost of labor alone is already close to $1,000.
Additionally, a set of 24 premium valve springs costs about $200. The final price is now $1,200. Remember to spend an additional $50 on a few gaskets and its stem seal replacements along the road.
Four Cylinder Engine
It typically takes three hours to replace all of them on a straightforward four-cylinder engine, such as the ones used in the Honda Civic. Therefore, labor would cost between $220 and $300.
Regarding valve springs, a set of 16 can be purchased for about $56 and comes with a one-year warranty.
The cost will increase to about $100 when buying an OEM set or, at the very least, from a recognized brand. Thus, the total cost to complete the replacement falls between $330 and 370.
Pushrod Engine
The average time needed to replace it on an American pushrod engine is between 5 and 5.5 hours. Accordingly, the total labor expense will be $440, varying with your area.
A complete set of 16 double valve springs, valve stem seals, and retainers cost about $400 for some vehicles. Depending on your engine, this brings the total price to $650 to $850.
FAQs
How Often Should You Replace Your Valve Spring?
When your valve spring is not moving or breaks, replacement is necessary. Do you need to replace it if it hasn’t been damaged?
If you bought it about a month ago, the answer is no. Yet, you should replace it every 30,000 to 60,000 miles or every 2 – 3 years. Even without any signs of wear and tear, its tension and performance certainly can’t equal a new one.
What Causes The Floating Valve?
When the springs can’t keep up with the engine’s speed, they can float. When the motor runs at a high RPM (more than 5000 RPM), they opens and shuts quickly.
The cam is turning at 5000 RPM and pulling them open over 40 times per second at 2500 RPM.
Therefore, if this part is weak, they might not be able to fully close it before the next cycle of opening starts.
The engine will misfire and lose power if it doesn’t close. When this happens, the cylinders will lose compression.
What If I Continue Driving With Broken Valve Spring?
An engine’s weak or broken valve springs can result in tons of performance problems. This ends up with compression loss and might seriously harm an engine’s internal components.
It is acceptable to continue driving with a broken spring for a short time. Still, if you do not repair it soon, it can leave further damage on the components involved. This can put you in danger during your trip.
Bottom Lines
You may find many broken valve spring causes. However, the only solution to this situation is to replace it with a new one.
Don’t try to use the old one. It will no longer have the same tension as the original, and the efficiency is also reduced significantly.
Replacing a new spring is not expensive or takes too much time.