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What are the common symptoms of bent valves? Would they stop your engine from running? Well, bent valves can wreck an engine totally. Yes, having a bent valve is a serious issue, and you shouldn’t keep driving when one or more valve is bent.
One of the most common symptoms of bent valves is a “very” noisy engine. Since the bent valve prevents emissions from going out – and also prevents air from getting into the engine cylinders, you could hear a serious loud noise as you drive.
Bent valves can trigger quite a lot of unusual signs and symptoms. Below, we have mentioned the commonest signs of bent valves and what you should do in such a situation.
Common Symptoms of Bent Valves
There are many things that could cause your engine’s valve to bend, but the major causes are a bad timing belt and excessive overheating.
Your valves could go bad while still driving, and when that happens, you’d instantly experience any of these signs.
1. Instant Power Loss
If you were driving when the valve went bad, you’d notice an instant loss of power. It’d seem like your engine can’t power up anymore and the performance would drop drastically.
A bad valve would cause poor combustion inside the engine’s chamber and that’s what causes the power loss.
2. Loud Engine Noise

Apparently, a bent valve would cause a loud unusual noise when you try to drive or accelerate.
This noise is loud because air is trapped inside the cylinder that has the bent valve – the bent valve prevents air from escaping; hence the noise. When you hear such a noise, one of the first things to check is your engine valves.
3. Increase in Oil Usage
If your car suddenly starts using more oil than ever, that could also be a sign of a bent valve. A bad valve can affect the engine’s performance – make the engine use more oil, yet performance won’t be improved.
4. Check Engine Light Is On
Once a problem with your car affects the engine, the check engine light will come on. It illuminates to draw your attention to your engine because the car’s central computer detected that something is not right in there (the engine).
While we know that there are many reasons why the Check Engine light may illuminate on your car’s dashboard, it is important to say that bent valves are also among the triggers.
5. Shakes
Another thing that could happen when your valves bend is “engine shaking.” You’d notice that your car shakes as you drive; misfiring may also occur due to bent valves.
So, when you experience such abnormal symptoms, it’s time to check the valves, and probably replace them.
6. Car Won’t Start
There are many valves in different valves; the exact number of valves in a vehicle depends on the number of cylinders the engine uses to work. If it’s just one or two valves that got bent, the car may still start and drive (but you’d notice a lot of anomalies).
On the other hand, if there are more bad/bent valves than the good ones, then the car is mostly not going to start. If it gets to this extent, it is advisable not to force the car to start, else, you may wreck your engine.
Read Also: Will a Car Run With Bent Valves?
What More?
These common symptoms of bent valves can occur on any vehicle (once the valves are no longer in good shape). More so, some mechanics allege that bent valves can cause low cylinder compression.
However, generally, bent valves would cause an engine to lose power, and in worst scenarios, it can cause the cat not to start at all.