Engine misfiring? Get your car inspected at your home or office.

Our certified mobile mechanics come to you 7 days a week between 7 AM and 9 PM.

Estimate price near me

Service Location

Customer Ratings

(413)

How A Diagnostic Works

Instantly book a certified mobile mechanic to come to you

Mechanic diagnoses the problem and quotes necessary repairs

Your vehicle is ready to go

Fair, upfront & transparent pricing for all services

Our certified mobile mechanics can come to you now.

Customer Ratings

(413)


Engine is misfiring Inspection Service

When an engines misfires, it’s usually readily apparent to the driver from the stuttering and jerking produced by the engine when one or more cylinders fails to fire properly, either because of ignition- or fuel-related issues. It is accompanied by a loss of power in direct proportion to the severity of the misfire.

It can be tricky for to track down the problem if the misfire only occurs under certain circumstances, for example, under load. Not all misfires occur across the operating spectrum.

For older vehicles:

On older, carbureted vehicles, the culprit will almost certainly be in the ignition system as older vehicles lack many of the sophisticated sensors that can cause a misfire. A vacuum leak or a faulty fuel pump can also cause this symptom as well. The first thing the mechanic will do is determine which cylinder or cylinders is misfiring, and the spark plug color is probably the best way to tell. The guilty plug will most likely be grayer than the others, which should tend toward brown coloring. If needed, the spark plug can be replaced.

The next step would be checking the wiring to that plug for cracks and deterioration, and replace as necessary.

For most modern vehicles:

In modern cars, misfiring will invariably be accompanied by a Check Engine light. In fact, checking for efficient combustion was the primary reason the U.S. government introduced the rules for OBD-II (on-board diagnostics, second generation). It was part of the push toward cleaner exhaust emissions.

A code reader will tell you which cylinder is to blame, but it may not say whether it is a problem relating to the injector serving that cylinder or the systems delivering the ignition spark. As with older vehicles, a look at the wires and spark plugs is a good idea. Checking them in the dark will sometimes reveal errant spark tracking, as will spraying them with a fine water mist.

One way mechanics check which spark plug is failing to hold its own is by running the engine at an idle speed high enough to produce the misfire, then removing leads from the coilpack (the unit that looks like the distributor we are used to seeing in older vehicles ) one by one. Most removals will cause a profound change in idling performance, but a defective wire will not. That will suggest that it’s either the spark plug or the coil serving that cylinder at fault. If a new spark plug at that cylinder does not remove the stumble, the mechanic may need to replace the coil pack or the wires as a set.

If it isn’t an ignition issue, then the injectors will need to be checked. A mechanic uses a multimeter to check the resistance value at each injector. It may be a bit difficult to reach them, sometimes requiring the removal of an engine cover and the intake manifold. The mechanic disconnects the injector, then touches the multimeter probes to the two connector prongs to read the value, in Ohms. If any of the injectors read outside of the specified values, they will need to be replaced.

Along the same lines, a fuel pump starting to go bad can also cause misfires or similar issues and can be diagnosed with a fuel pressure check of the entire system with the appropriate equipment. This should only be done by a qualified mechanic as the fuel system is highly pressurized and of course, fuel is flammable.

Common reasons for this to happen:

  • Faulty spark plugs or wires
  • Faulty ignition coil
  • Broken piston rings
  • Burnt or bent valves
  • Broken valve springs
  • Camshaft worn out
  • Fuel injector is not working

What to expect:

A top-rated mobile mechanic will come to your home or office to determine the source and cause of the misfiring engine, and will then provide a detailed inspection report that includes the scope and cost of the necessary repairs.

How important is this service?

A misfiring engine is accompanied by a loss of power, which makes this issue a critical one to correct promptly. Book a mechanic to perform a thorough inspection as soon as possible.


Recent Engine is misfiring Inspection reviews

Excellent Rating

(413)

Rating Summary
387
13
3
3
7
387
13
3
3
7

John

27 years of experience
1013 reviews
John
27 years of experience
Ford Taurus V6-3.5L - Engine is misfiring - League City, Texas
John is very very well mannered person, He explains all his work very well. If needed I will book him again.

Theodore

16 years of experience
1581 reviews
Theodore
16 years of experience
Nissan Versa L4-1.8L - Engine is misfiring - Renton, Washington
Theodore arrived on time he was very professional and got me back on the road in no time I definitely recommend

Brian

18 years of experience
35 reviews
Brian
18 years of experience
BMW 528i L6-3.0L - Engine is misfiring - Hampton, Georgia
Brian was very knowledgeable and explained everything in detail. I recommend using him! He was outstanding!

Keven

7 years of experience
114 reviews
Keven
7 years of experience
BMW 328i L6-3.0L - Engine is misfiring - Tacoma, Washington
Keven was very professional and explain every thing in detail. He was polite and knowledgeable. I would recommend him to friends and family.

Recent articles & questions

A Buyer’s Guide to the 2012 Nissan Murano
The The 2012 Nissan Murano is a sleek crossover SUV that has all the modern amenities. It has ample interior space with a luxurious feel, and a driver oriented suspension. If you need a vehicle that can hold passengers and...
Cell Phones and Texting: Distracted Driving Laws in New Hampshire
New New Hampshire has some of the strictest laws in the country when it comes to cell phones, texting, and driving. New laws went into effect on July 1, of 2015 to prohibit the use of any device which is...
What are the Car Pool Rules in Nevada?
Nevada Nevada is not a city that’s known for its freeways. The state is known mostly for the glitz and glamor of Las Vegas, but when it comes to driving, people associate Nevada with long, gorgeous, rural dessert roads (https://www.yourmechanic.com/article/top-10-scenic-drives-in-nevada),...

My car want start and when it do it shut down and want start until 30 minute or so. Now it want do nothing

When a car turns and won't start, it is called a "crank no start". When this occurs, the first thing you need to do is see what is missing. All internal combustion motors need spark, fuel, injector pulse and camshaft...

Hey two days ago I drove up to my buddy's place and asked him a question about my charger since he acts like a mechanic I thou

This may be difficult to diagnose without knowing which fuses were moved around. There are a number of fuses that could cause the car to not start if removed or switched. There is a battery power fuse (30 Amp), an...

Heater making loud rumbling noise when on high 1996 Saturn SL2

Hi there - I believe the heater fan motor bearings (https://www.yourmechanic.com/article/how-to-buy-a-good-quality-heater-blower-motor) are shot, and that's the noise you hear - increasing noise level as fan speed goes up. These bearings are generally not serviceable, and the fan motor should be...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

+1 (855) 347-2779 · hi@yourmechanic.com