Skip the auto shop - Our mechanics make house calls

Q: Flashing Check Engine Light is on. The engine shakes at idle and has low power.

asked by on

My car started to shakes like a a piston isnt firing? How would I know,if is a dead cylinder or a bad coil I recently replaced sparkplugs and oiil I know it could be mechanical or electronics so I would like to know which order should I tske to diagnose the problem

My car has 170000 miles.
My car has an automatic transmission.

Hi, the first task is to extract the problem codes which are causing the Check Engine light to flash. Most auto parts stores will do this for free. I would suspect plug wires next, and check the condition of the distributor cap and rotor while checking the plug wires.

Pull one plug wire off at a time, then start the engine. If disconnecting the plug in one specific cylinder does NOT make a difference in how the engine runs, that plug wire is your first suspect. With the age of the car, and your mileage, replacing all of the wires is the right decision, even if only one wire is bad.

To avoid any unnecessary repairs, I would recommend having a misfiring inspection completed by a mobile, professional mechanic, such as one from YourMechanic, to diagnose this problem, get an accurate assessment of damage and cost estimate for repairs.

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
  1. Home
  2. Questions
  3. Flashing Check Engine Light is on. The engine shakes at idle and has low power.

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

Get a quote

What others are asking

Q: Ecu not grounding ac circuit or fans for ac to work.

Everything in the A/C system and heater is controlled by the A/C heat control panel module. If fuse 17 on the inside fuse panel and fuse 47 in the outside engine compartment fuse box are both good and the ECU...

Q: Car shaking and misfiring

Hi. The first thing to do is check the codes stored in the engine computer. If the engine is indeed misfiring, codes will be stored. The source of the misfire will need to be identified, possible faults include a failing...

Q: Does guaranteed 2 pass mess up motors ?

Hello, thank you for writing in. While this product may not directly effect a perfectly good engine, if there are other issues with it, the problems may be exaggerated by the product. Also keep in mind that the product is...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
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...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.