There are some car repairs you can put of for a few days, weeks, or even indefinitely, as long as the rest of your car’s components are in ideal condition and operating optimally, but are bent valves one of them? Moreover, is it even safe to drive your car, even to the mechanic, with bent valves, or are your only options between a DIY garage fix and a tow truck?
It is not advisable to drive a car with bent valves, as this will cause an imbalance of compression, inhibiting the cylinders’ ability to seal properly and often resulting in an engine misfire. If only one valve is bent and/or the bend is minimal, your car might start, but will likely stall during the drive.
If your car has a confirmed bent valve, read on as we discuss the repair and replacement options, so you know what to expect going forward with this issue. Additionally, we’ll list some of the tell-tale signs of a bent engine valve for anyone who might suspect this is the root cause of their car’s problems, along with preventative measures to ensure you never have to pay this pricy repair in the future.
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Can Bent Valves Be Fixed?
After you’ve received the diagnostic that your car’s engine has one or multiple bent valves, the first question you’re most likely to ask is whether this can be fixed, perhaps by simply bending them back into place.
Yes, a bent car engine valve can be fixed, to some degree. The extent of this repair will depend largely on:
How bent is the valve?
How many valves are bent?
How much damage has the bent valve(s) caused to surrounding components?
If you’re lucky enough to discover this issue early on when there is minimal surrounding damage and only one valve is minimally bent, the issue can usually be fixed by removing and replacing the engine head and repairing any cracked or damaged valve seats.
That being said, it is not uncommon for a bent valve(s) to be damaged to the point that they need to be replaced completely.
How Much Is a Repair?
The answer to this question truly depends on the extent of damage. On average, the cost of repairing or replacing a bent engine valve ranges from $300-$400. While that’s certainly a hefty sum, it isn’t necessarily the only figure at play here.
Unfortunately, when it comes to a bent valve, the valve repair or replacement itself is usually the least of your concerns. This is because there are two other types of damage you or your mechanic will be looking for as well: damage on the component that bent the valve, and damage on other components caused by the valve.
It’s no surprise that engine valves don’t just suddenly bend on their own; something has to knock into them, most likely the car’s pistons (although damage to other components could also lead to this pricy collision). Pistons can be extremely expensive to repair and replace, more specifically their rings. While
the parts themselves tend to be $40-$200, the cost of labor can be anywhere form $1,000-$5,000.
Now, you have to consider what surrounding components your bent engine valve might have damaged, either upon impact with whatever bent it in the first place, or during the occasions you’ve run the engine since. Apart from the piston, the most common sources of damage will be found in the valve guide and seals, the valve seat, and any big and small end bearings for the cylinder(s).
Once you add up these potential damages, you’ll quickly find yourself faced with a repair bill of several thousand dollars. So, while you certainly can fix a bent engine valve, you might have to consider if this and its associated repairs are worthwhile considering the value of your car.
Noticeable Symptoms of Bent Engine Valves
Before you start sweating bullets over that potential repair bill, let’s make sure a bent valve is even the cause of your car’s issues.
There are several noticeable symptoms of a bent engine valve, namely:
Engine noise
Engine misfire
Check engine light on
Low compression and reduced power
While these signs individually won’t always mean a bent valve is to blame, a combination of them is likely enough cause to have your valves closely inspected.
Engine Noise
This is arguably one of the most easily noticeable signs on this list, as any driver can recognize uncommon engine sounds regardless of their mechanical experience. Typically, when an engine valve is bent, you’ll notice ticking or tapping sounds coming from under the hood. You might even notice your engine is shaking if the bent valve was caused or has led to a broken timing belt.
Engine Misfire
Another highly noticeable and unnerving sign that your car has a bent valve is a misfiring engine. This occurs when the exhaust valve is bent, preventing them from opening and closing at the proper time to maintain optimal pressure, and therefore, inhibiting your car’s ability to expel fumes effectively.
The result is usually a gas leak paired with other issues, such as stalling or jerking while driving or a backfire or popping sound from the exhaust. You might also notice excessive fuel consumption, as your car’s engine attempts to function properly.
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Check Engine Light On
The check engine light popping on can indicate a series of things might be wrong with your car. While a bent valve isn’t usually the most likely reason why this icon appears, if your car is experiencing this issue, it’s certainly enough to bring it permanently to your dashboard and warrant a trip to the mechanic.
Low Compression and Reduced Power
As we mentioned previously, having a bent valve is going to cause in imbalance of compression as it will prevent the cylinders from sealing properly. Not only will this result in low pressure, but the excessive release of air and exhaust fumes result can also affect your car’s power capabilities. The easiest way to check this tell-tale sign is to perform a compression test.
How To Prevent Bent Valves
By this point, you know the extent of what a bent valve might cost and what signs to look out for that might indicate the presence of this issue. After reading the havoc a bent valve can reap on your car and the thousands of dollars it can cost in repairs, its understandable you’d want to know how to ensure this is never a problem your current or any future cars experience.
The best way to prevent bent valves in a car is to be conscious of the top causes behind this issue and be proactive about avoiding them through safe engine use and regular maintenance.
We stated that bent valves are caused by this component knocking into another inside your car. While this is true, there are some overarching reasons why this happens.
Don’t Over Rev The Engine
The leading causing of bent valves is actually over revving your car’s engine. Because most cars are equipped with an automatic transmission, this isn’t usually an issue nowadays, as over revving occurs when you run the engine higher than the manufacturer’s redline (ex. downshifting into a gear that is too low for the car’s current traveling speed). However, if you drive a car with a manual transmission, this is a very real concern you should be aware and avoid.
Keep the Timing Belt in Optimal Condition
The next leading cause is a damaged timing belt, as this component can easily snap or collide with those around it, including your exhaust or intake valves. To avoid this, you’ll check the conditions of these belts regularly and replace them at the appropriate wear/mileage point (usually every 60,000 to 100,000 miles).
Never Run the Engine With Low Oil
Lastly, you must keep your engine’s oil levels at the optimal levels at all times. This liquid is essential for numerous functions within your car, including keeping your valves lubricated. While this is more vital to ensuring your valves don’t stick, rather than bend, sticking is what can cause the valve to knock a piston and start a series of expensive damages.
Final Thoughts
A bent valve isn’t necessarily a death sentence for your car, but it’s certainly a problem you want to avoid. Make sure you follow the preventative measure listed above, and if you notice one or multiple symptoms that might indicate a bent valve, take your car to a professional mechanic.
Sources:
https://mechanicbase.com/engine/bent-engine-valve-symptoms/
https://www.repairsmith.com/i/blog/how-to-care-for-your-car-intake-and-exhaust-valves/
https://oards.com/bent-valves-symptoms/