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Can a Bad Valve Cover Gasket Cause Smoke? (Read This First!)

When dealing with engines, you should always keep your eyes and nose on alert. A lot of things can go wrong when it comes to dealing with engines. Make sure you are aware of all the situations that might fall in your hands.

Can a bad valve cover gasket cause smoke?

A bad valve can cause smoke and it can be dangerous as well. From the leaking valve cover, oil will start to drip down and hit the already hot exhaust manifold. And as it happens, the oil will burn that will create the smoke. The smoke would be from the engine compartment mostly.

You might notice the valve cover leaking a little. It may not seem as a huge deal initially but it could lead to a smoke. The smoke is more likely to come from the engine compartment. This happens when the drips of the oil falls on the already hot manifold.

A bad valve cover will lead to some smoke coming from the engine compartment. There is very little chance of no smoke coming out if the valve is not working properly or is leaking. A bad valve will leak and the leakage will cause smoke to come out of the engine compartment.

From exhaust:

Usually when smoke comes out due to a bad valve, it is not from the exhaust compartment but usually from the engine bank.

The smoke does not come from the exhaust compartment, and that is how you know that it is the valve that is leaking, not any other place.

The exhaust compartment does not link with the valve. So any leakage in the valve will not make smoke come out of the exhaust. Rather, the smoke will come from the engine compartment, where the leakage of the oil will drop on the already hot manifold.

If you notice smoke come out of the exhaust compartment, it may be because of some other reason.

Cause a bad valve will make smoke come out of the engine compartment, not the exhaust. The leaking oil will hit the hot manifold and that will create a smoke to form.

Will leaking valve cover gasket cause smoke?

A bad valve cover gasket is generally a leaking valve cover gasket. And it is a known fact that a bad valve cover gasket that leaks will cause smoke to come out of the engine compartment.

In most cases the smoke from the engine compartment indicates a bad valve casket.

When a valve cover gasket goes bad it starts to leak oil. The leaking oil will drip down the engine and on to the manifold which is already hot. This will cause oil to burn. Which will cause a smoke to come out of the engine compartment.

A smoke from the engine compartment could lead to a lot of things gone wrong. But the initial response of this smoke should be to check the valve cover gasket.

The smoke comes out when the valve cover gasket starts to leak oil onto the hot manifold. Usually, a bad valve cover gasket causes smoke.

Will bad valve cover gasket cause these smoke?

The color of the smoke that comes out of the engine compartment can be a major indicator as to what is wrong. A leaking valve cover casket will emit smoke as well.

You have take notice of the color of the smoke. The color indicates what is wrong with the engine or the exhaust compartment.

White smoke:

White smoke does not usually come because of a bad valve cover casket. White smoke indicates some problem in the exhaust compartment. Which is not related to the valve cover gasket.

Blue smoke:

A leaking valve cover gasket will emit a smoke with a hint of blue. The smoke coming out of the engine compartment will be have a blue hue.

Black smoke:

Usually any issue from the engine compartment will cause a black smoke to come out. If your valve cover is leaking the smoke from the engine compartment will be black.

2 reasons why bad valve cover gasket cause smoke

A bad valve cover gasket will cause a smoke to come out of the engine compartment. This happens when the valve cover gasket has a leak and oil drips from there onto the hot manifold. This leakage is the prime reason for smoke to come out of the engine compartment.

Leaking cover gasket:

A leaking valve casket will cause oil to drip from the gasket to the engine compartment. There the manifold is already hot.

So when the oil touches the manifold of the engine that is already heated, the oil drops start to burn. This causes minor smoke to come out of the engine compartment.

If the leakage is for a good amount of time, the dripping oil will cause a smoke. As the manifold inside the engine compartment is already hot, it will cause the drips of the oil to burn. If there is enough oil burning, you will notice smoke.

Failing cover gasket:

If the valve casket somehow fails to work, it will start to leak inside the engine.

As the engine compartment is confined, the burning oil will be trapped inside the compartment. It will keep mixing with the air and gas inside the compartment. Which will cause a smoke to come out of the engine compartment.

Smoke coming out of the engine compartment is common when you have a leaking valve cover gasket. As there is no other way for the oil to go out. It will mix with the already existing gasses inside the compartment. Which will create a new smoke.

What are the signs of a bad valve cover gasket?

A valve cover gasket does not usually get damaged or bad as a matter of fact. So it may be difficult to figure out if the valve cover gasket has gone bad or not. But there are some clear signs that the valve cover gasket either leaking or has gone bad.

Other than the very obvious sign, which is when smoke starts to come out of the engine compartment, there are some indications that can tell you if there is something wrong in the valve cover gasket-

  • The oil leaks will be visible, as in you will see drips of oil around the engine or the manifold.
  • The oil level of the engine will always show low or empty.
  • You will smell oil burning, even if you turn off the engine.
  • You will notice some rough idling.
  • The engine might misfire.
  • The dashboard will start blinking the emergency lights.
  • Blue smoke will start to come out of the engine compartment.

It is not uncommon for a valve cover gasket to be damaged and leaking. Just keep a look out for these signs and indications. As soon as you see any of these signs make sure to take measures to prevent further damage.

How to fix a bad valve cover gasket causing smoke?

A bad valve cover gasket can be a a huge issue. If it is not fixed the oil will keep leaking constantly and it will cause permanent damage, not to mention the financial issue because of the empty oil level.

When you notice the valve cover gasket go bad, make sure to get professional help.

The best way to fix this issue is to change or replace the valve cover all at once. Given below are the steps to do so-

Clench or cinch:

Try to gently clench or cinching down the valve cover bolts or use a torque wrench. Try not to over tighten the bolts. Sometimes this step alone solves the entire problem.

Remove parts:

As the engine cools down remove throttle cables, spark plug brackets, PCV hoses and anything else in the way. Remove the valve cover bolts.

Remove valve cover:

Lift and remove the valve cover. Make sure you do this very carefully and try not to misplace any other parts of the engine. To loosen the grip, try tapping the rubber mallet.

Install new:

Now you can install the new valve cover over the gasket.

Apply silicon:

In the places needed, apply silicon. Make sure there is no oil on the surface where you will apply silicon.

Tighten bolts:

Tighten the bolts to finish the job.

This is how you can fix a leaking valve cover gasket. Basically the only way is to change the broken valve cover and attach a new one. Make sure you get this done by a professional if you do not have the experience.

Final thoughts

A bad valve cover gasket can cause smoke to come out of the engine compartment. The leaking oil will drip onto the hot manifold and it will cause the oil to burn. Thus creating a black or blue smoke. As a valve cover gasket goes bad, it starts to leak and create smoke in the engine compartment.