Skip the auto shop - Our mechanics make house calls

Q: Car sputters, shakes, and check engine light on

asked by on

My vehicle started sputtering and shaking on my way to work. After about 10 miles, I stopped at a store. When getting back in my car and starting it, the check engine light came on, flashing on/off. My car had almost no horsepower and I couldn’t get over forty (uphill, maybe 10). Most of the time the MPG gauge stays around 28.5 mpg, but it dropped to 19. I drove on to work and it was parked all that time. After work, I started it and it was running fine, but the check engine light was on continually. There was better horsepower than there had been that morning, but it was not normal. After 10 miles, it started getting sluggish - more and more. After pulling over, I turned off the car and let it sit for over an hour. After restarting, the engine light was still flashing and it started running like it did that morning. The more gas I’d give it, the worse the car would run. Can you give me direction on what is causing this and how to correct it?

A: Typically, when the Check Engine Light is i...

Typically, when the Check Engine Light is illuminated and it is flashing, this is an indication that the vehicle's engine is misfiring. This would also explain the symptoms on your 2007 Lincoln MKZ. If the engine has a misfire, then each time that cylinder fires it will cause the engine to run rough for a split second. The higher the RPMs go, the more times the misfiring cylinder is required to fire, and therefore the rough running engine happens the whole time because that cylinder may be misfiring several times per second.

I would recommend having a certified technician take a look at your ignition system to diagnose the shaking and sputtering problem. This inspection would cover the spark plugs, the ignition coils, and any wiring that may be associated with those two parts.

The most common causes of the issue you are having is faulty spark plugs and faulty ignition coils. If a spark plug is the cause of your misfire, it is recommended that all the spark plugs be replaced at once for best maintenance practices.

If an ignition coil is the cause of the problem, it is okay to just replace one because each spark plug has its own ignition coil on that engine and would not have any affect on the other cylinders.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
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・Save up to 30%

Get a quote

What others are asking

Q: What type of carb to replace with?

Picking out the appropriate size carburetor is a factor of how much air your specific engine build will pump. This is measured in CFM's (cubic feet per minute). You are most likely correct in needing a smaller CFM carburetor. Your...

Q: Battery jumped, but idling, missing, goes up/down

Hi there. This happens frequently on this vehicle when there is a loss of power. I usually start by checking the fuses to make sure that none of them failed during the jump. If they are fine then I scan...

Q: My 2001 Lincoln Continental misfires while idling.

You may have an engine vacuum leak causing the engine to have a rough idle. The most common cause may be the PCV hose leaking at the connection of the hose where it connects to the back of the intake...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...