The Cylinder Balance Test
I have always tested two cylinders at a time when doing the manual cylinder balance test on the GM ignition coil pack equipped V6 engines.
If it's easier for you to test one cylinder at a time, then set up the test for one cylinder instead of the two suggested in the instructions below.
Remember: If the cylinder is "live", then touching the vacuum hose with your test light will cause the engine to idle rough (you'll definitely see it, feel it and hear it).
If the cylinder is "dead" to begin with, then touching the vacuum hose with the tip of the 12 Volt test light will not have any effect on your Chevy Malibu engine's idle.
NOTE: If you haven't read the section titled: Manual Cylinder Balance Test Essentials, then take a look at it now before starting the test: Manual Cylinder Balance Test Essentials.
These are the test steps:
- 1
Disconnect two spark plug wires from their ignition coil pack towers.
- 2
Insert the vacuum hoses into each spark plug cable end.
Now reconnect the spark plug cables back to their ignition coil towers. The vacuum hoses should be between the spark plug cables and their ignition coil towers. - 3
Have your helper crank and start the engine.
- 4
Touch each vacuum hose one at a time with the tip of the 12 Volt test light.
If the cylinder is dead, then touching the vacuum hose with the test light will have no effect on the engine's idle.
If the cylinder is live, then touching the vacuum hose will cause the engine's idle to roughen even more. - 5
Repeat steps 1 through 4 on the remaining four ignition coil towers.
Let's examine your test results:
CASE 1: The engine's idle became more rough when you shorted a cylinder. This test result tells you that that specific engine cylinder is not dead.
CASE 2: The engine's idle was not affected when you shorted a cylinder. This test result lets you know that that specific engine cylinder is dead (misfiring).
What usually causes a cylinder to go dead is a lack of spark or a lack of fuel or a lack of compression. Check out the next subheading to find out more.
I Found The Dead Cylinder, What Next?
Once you've found the dead cylinder (with the cylinder balance test) the next step is to find out why it's dead.
A dead cylinder usually is caused by one of three things:
- A lack of spark.
- A lack of fuel.
- A lack of compression.
A lack of spark is usually caused by one of the following:
- Defective high tension cable (spark plug cable).
- Defective ignition coil pack.
- A bad spark plug. The spark plug could be severely worn out, broken, or the air gap between the its center and side electrodes is closed or blocked with carbon build-up.
A lack of fuel is usually caused by a clogged or defective fuel injector.
A lack of compression is usually caused by severe wear and tear of the dead cylinder's piston rings or cylinder head valves.
My recommendation to you now is to start by checking for spark at the spark plug wire. You need to make sure that the dead cylinder is getting spark. I would also remove the spark plug and check its condition.
If the dead cylinder is getting spark and its spark plug is in good condition; I would then test the dead cylinder's fuel injector resistance.
If the ignition system components and fuel injector are okay; I would then test the engine compression (focusing on the compression test result of the dead cylinder).
More 3.5L V6 Chevy Malibu Tutorials
You can find a complete list of 3.5L V6 Chevy Malibu tutorials here: GM 3.5L V6 Index Of Articles.
Here's a list of articles, you'll find there:
