What is typically involved to repair a internal combustion engine that has a cylinder misfiring?

Question

I have a vehicle with a cylinder misfiring (according to my OBD-II code reader).  I have decided to have a mechanic repair it, as I have never performed a similar motor vehicle repair.
Note that the only consistent symptom besides throwing the cylinder misfire OBD-II code is a little accelerator hesitation.
Not consistent was also some really bad (perhaps metal on metal - hard to tell) grinding sound for about 10-20 seconds when first driving after not using the vehicle for over 2 months. It sounded real bad, but resolved on its own before I could even turn around and park.
To help me evaluate different mechanics, I would like to know what is likely required to properly diagnose and repair this problem.  With the knowledge you provide, I will hopefully be able to filter out the scammers and find a trustworthy mechanic for this job.

GdD · Answer

There are many reasons for a cylinder misfire, many of them you can check for yourself. Easy to check are:

Spark plugs: a worn plug, badly gapped plug or a fouled plug
Spark plug not fully in: check to make sure the plugs are inserted properly
Spark plug cables: worn, pinched or greasy cables may not transfer electricity properly. Also make sure the connections are clean
Coils: it's hard to check these without the right equipment, but easy to replace

Less easy:

Cylinder compression
Fuel Injectors
Fuel Pressure
Valve seating

It would make sense to check the easy things yourself and possibly save yourself some money.

What is typically involved to repair a internal combustion engine that has a cylinder misfiring?

One Answer

Add your own answers!

Ask a Question