Q: Bad 5th cylinder - misfiring?

asked by on

Does it need valve job or piston work

My car has 175000 miles.

It is unlikely that your motor needs a valve job or piston work judging by the amount of miles, absent some kind of catastrophic failure inside your motor. Often times, engines will have misfires for a wide variety of reasons that can cause a "dead cylinder" problem.

Engine misfires can be caused by a list of problems, but there are a few suspects that occur more than others. Generally, misfires are caused by either a spark or fuel issue or in cases, a combination of both. Spark related problems generally will result from things like ignition coils, crankshaft position sensor, spark plugs, spark plug wires or ignition modules not working properly. When the misfire results from a fuel related issue, this is commonly related to a lean fuel condition (lack of sufficient fuel supply to the motor).

Fuel related misfires can be caused by many different things such as low fuel pressure, faulty or dirty fuel injectors, a faulty O2 sensor, a dirty or failing mass air flow sensor, a faulty or dirty idle air control valve or a vacuum or intake leak. When the fuel supplied to the combustion chamber is insufficient, this results in an ignition (spark) that is igniting a less than balanced load of fuel and air. This results in a misfire or an explosion in the cylinder that is much less powerful than the other cylinders. This creates a loss of power that resonates throughout the motor additionally causing other problems with ignition and fuel timing. I would recommend having an expert from YourMechanic come to your location to diagnose your misfiring problem.

Was this answer helpful?
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. Bad 5th cylinder - misfiring?

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: Getting several codes fuel system too lean, Misfire cylinder 3 fuel cut off, misfire detected with low fuel

System too lean means that the fuel mixture has moved beyond the ability of the feedback system to compensate. One thing that can cause that is an air leak that enables air to enter the intake system without passing first...

Q: My 2001 Tacoma will drive fine for about 20 minutes and then I can’t go over 20 mph, meanwhile the rpm will go up and down as I pr

Hello Wesley. Thanks for contacting us today. It is quite likely that your Tacoma is stuck in what's referred to as a Limp Mode. This happens when the ECU detects a fault within the driveline and limits the speed of...

Q: Shaking when in overdrive

Hi there. Check the fuel system and see if the fuel injector for cylinder number 2 is malfunctioning. The code P0402 means that the EGR is not functioning and the code P0174 means that Bank 2 is lean, which is...

Related articles

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...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
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.