Q: Spark plug not working

asked by on February 25, 2016

One spark plug is not working, causing the engine to miss while driving. I don't know if all the spark plugs need to be changed or just the one (number six spark plug is not working). Also, the valve cover gaskets leak and the oil pan leaks.

Spark Plugs Replacement $98.11 - $669.97 Get a Quote

A cylinder #6 misfire doesn’t necessarily mean the plug is bad. There are many other things that could cause a single cylinder misfire, from a faulty fuel injector to an engine mechanical problem. Anything that causes incomplete or abnormal combustion could be the cause. If your valve covers are leaking, there is a chance that the spark plug tube seals are allowing oil to get into the spark plug hole. This could cause a misfire and contaminate the plug. If the #6 spark plug is indeed causing the misfire, I suggest replacing all the plugs since the others are probably worn as well. I recommend having a professional, such as one from YourMechanic, inspect your vehicle firsthand. They will be able to determine the correct repairs and replace your spark plugs if needed.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

Mass Air flow sensor cleaning

Hello, thank you for writing in. The mass air flow sensor should not be cleaned with carburetor cleaner. Carb cleaner leaves an oily type residue that is not good for the electronics within the MAF sensor. Use the appropriately designed...

I have a 99 Chevy Tahoe and when I was driving it got hot real fast and turn off and when I tried to start it up it turned off

Hello there. I think we answered your question a few minutes ago, but if not - here is what we suggested. It's quite possible you have two separate things going on with your Chevrolet. First, if the vehicle gets really...

Applying brakes at stop lights and the vehicle slides.

Hello. If the brakes are staying applied and the wheels are locked but the vehicle begins to slide it is because of the slickness of the roadway. There is not going to be any way to prevent this unless you...

I just got a new transmission put in my car and it drives and reverse but won't go up hill.

This may be a sign of a faulty transmission control solenoid. As you know, automatic transmissions use pressurized hydraulic fluid to change gears. Every time a gear change is required, the car's computer activates a transmission solenoid, which directs transmission...

Ignition coil pack is not firing (1 out of 3)

It is not uncommon for an ignition coil to fail. Ignition coils are coated with a varnish-like insulation that becomes brittle over time after being stretched then contracted repeated as the copper beneath them expands and contracts much quicker than...

Temperature gauge on dashboard

If by replacing the "temperature valve" you are referring to the thermostat (which does in fact act as a valve in a way), then you might have an electrical issue. Assuming with the repairs you have done, that the cooling...

Well the check engine light is blinking. A track light keeps coming on and there seems to be loss of power. Engine running rough.

Hello. If the check engine light is flashing then that typically means that there is a cylinder misfire. This can be caused by a bad spark plug, spark plug coil, or fuel injector. It can also be caused by something...

ABS Light, car shakes while braking

Usually when the ABS light is on the dashboard it's caused by a faulty wheel speed sensor, ABS module, or low brake fluid levels. The fact that the car shakes when you apply the brakes at 60 mph is concerning...

Hard shifting and thunking noise at the rear end

Hello. The shift lever should remain stable unless it's moved by the driver. If it pops out of gear, even after a transmission replacement, I suggest inspecting the transmission mounts, engine mounts, and subframe bushings. Cases show that the subframe...

Related articles

Are There Different Kinds of Spark Plugs?
Your Your engine needs at least one spark plug per cylinder to ignite the fuel and air mixture and make the engine run. But not all spark plugs are the same. There are several different types on the market, and...
The Best Used Cars to Buy for Senior Citizens
Everyone Everyone needs a way to get around. You need to get groceries, get to doctors’ appointments, visit with family and more. However, senior citizens have very different needs when it comes to buying a used car than other demographics....
How Long Does a Proportioning / Combination Valve Last?
Modern Modern brake systems are far more advanced than they were even a few years ago. Today, most cars come with front disc and rear drum brakes (although many also come with four-wheel disc brakes). In a disc/drum combination system,...