Skip the auto shop - Our mechanics make house calls

Q: misfire in cylinder #1

asked by on

I've had this mis fire for a while now, even after replacing the spark plugs, spark plug wires, distributor cap, coil pack, and fuel injectors. And it will every once in a while idle ruff on the start or have issues not wanting to turn over, and some gas has to be given until it doesn't want to shut off.Also, every once and a while (once a week probably) it will shut off at a light or stop and sometimes while driving. It seems when the jeep warms up it runs better. Please help I don't know what else I can do to solve this. Thank you

My car has 200000 miles.
My car has an automatic transmission.

A: It is possible that your number one cylinde...

It is possible that your number one cylinder could be misfiring due to low compression in that cylinder. I would recommend having a compression test performed by a qualified mechanic to determine if the piston rings are holding up to the compression that they are exposed to. The manufacturer releases a compression specification that this number will be compared against.

If the compression is low in the number one cylinder, the piston rings may be faulty and need replacement or the cylinder walls are far too worn down due to lack of lubrication and are no longer able to hold compression even with good rings. In this case, the engine block would likely need to be bored out slightly and replaced with larger pistons or a new engine would need to be installed.

At 200k miles, it is not uncommon for a cylinder to lose compression due to piston ring failure. Engine blocks being too worn out is an unlikely cause, but is still possible. I would also check your exhaust for white smoke. If you have white smoke coming from your tailpipe (even intermittently) this means your engine is burning oil and could be an indication that your compression in one of your cylinders could potentially be low.

I’d recommend having the vehicle checked out by a qualified mechanic who can diagnose your misfire firsthand to pinpoint the fault.

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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

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: Car stalls while driving 1998 Dodge 2500 5.9L manual transmission vehicle

Hello - to directly answer your question, "Yes", a failing crankshaft position sensor can cause stalling while driving, sometimes because of heat-related failure, other failure modes may include a pothole or other jolt while driving. If it does turn on...

Q: Random hiccups and fuel problems, what could it be?

The fuel pump relay is most likely staying engaged even though you have turned it off. A malfunctioning fuel pump relay can also lead to the pump not turning on at all or it shutting off intermittently and without warning....

Q: New starter and battery, damn thing still won't turn over.

Hi there. It sounds like there is either a short to power or feedback occurring in an electrical circuit. Locating the faulty circuit can be time consuming, but it can be accomplished. Look for chaffed/melted wiring and corroded connectors and...

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...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
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.