Testing the engine compression on the 2.2L engine in your Buick Century or Oldsmobile Cutlass Ciera is a breeze.
What makes it a breeze is the fact that the spark plugs are accessible (since they have to be removed).
With the help of this tutorial, you'll quickly find out if an engine compression problem is causing a drivability problem or an engine no-start problem.
Contents of this tutorial:
You can find this tutorial in Spanish here: Cómo Probar La Compresión Del Motor (1993-1996 2.2L Buick Century, Oldsmobile Cutlass Ciera) (at: autotecnico-online.com).
APPLIES TO: This tutorial applies to the following vehicles:
- 2.2L Buick Century: 1993, 1994, 1995, 1996.
- 2.2L Oldsmobile Cutlass Ciera: 1993, 1994, 1995.
- 2.2L Oldsmobile Ciera: 1996.
Symptoms Of Low Or No Engine Compression
Over the years, I've noticed that engine compression problems usually cause one of two issues:
- The engine compression problem causes the engine not to start.
- The engine compression problem causes the engine to run, but it idles rough or misfires.
Here's a basic breakdown of the symptoms you'll see when the engine starts but is suffering an engine compression problem:
- Bad gas mileage.
- A heavier exhaust smell coming out of its tailpipe.
- Engine is not as peppy as it was once.
- Rough idle that goes away as soon as you accelerate the engine.
Which Compression Tester Should I Buy?
There are lot of engine compression testers to choose from and many places to buy them. I'm gonna' make two recommendations to you:
1) Which one to buy: The engine compression tester that I have always used is the Actron CP7827 Compression Tester Kit. My only complaint about this engine compression tester is that it does not come with a case to store it in.
Engine Compression Gauge Testers
2) Where to buy: You can buy an engine compression tester just about anywhere, but you'll end up paying more for it (especially at your local auto parts store). The above links will help you comparison shop. I think you'll agree it's the better way to save money on the compression tester!
TEST 1: Dry Engine Compression Test
I'm going to suggest that you test all four cylinders to get the most accurate test result from your compression test.
Of course, if you have one cylinder you want to test instead of testing all of them, by all means, do.
You're going to need an engine compression tester. You can borrow one from your local auto parts store (AutoZone, O'Reilly's Auto Parts, etc.) or buy one online. Here are my recommendations: Which Compression Tester Should I Buy?
IMPORTANT: Do not remove the spark plugs if the engine is hot. If the engine has been running for any amount of time, let it cool down completely before removing the spark plugs.
CAUTION: Take all necessary safety precautions. The engine has to be cranked to perform the engine compression test. Be careful and think safety all the time!
Okay, to get this show on the road, this is what you need to do:
Disable the fuel system by removing the fuel pump relay.
This will prevent fuel from being injected into the cylinders as you crank the engine.
Disable the ignition system by disconnecting the ignition coil/ignition module assembly from its electrical connector(s).
Don't overlook this step, since disabling the ignition system will prevent the ignition coil pack from firing spark during the test.
Disconnect all 4 spark plug wires from their spark plugs.
I recommend labeling the spark plug wires before removing them so you'll know where they go when you put them back on.
Remove the spark plugs.
As you' re taking them out, be careful and don't drop any of them on the floor, or you could cause the spark plug's ceramic insulator to break, and this will cause a misfire!
Thread the engine compression gauge into the spark plug hole for the number 1 engine cylinder (this is the spark plug hole closest to the drive belt).
IMPORTANT: Hand tighten the compression gauge only! Do not use any type of tool to get it tight.
When the tester is set up, ask your helper to crank the engine. Your job is to keep your eye on the compression tester's gauge.
Once the needle on the gauge stops climbing, have your helper stop cranking the engine.
Write down the compression value on a piece of paper.
Include the number of the cylinder this reading belongs to.
Repeat steps 5 thru 8 on the remaining cylinders.
Let's take a look at what your test results mean:
CASE 1: 0 PSI compression in 2 or all 4 cylinders. This test result indicates a serious internal problem.
The most common issues would be:
- Blown head gasket.
- Broken timing chain or timing gear.
- Engine threw a rod.
CASE 2: Low compression in one or more cylinders. It's not unusual for the compression values to vary between cylinders.
But if these values vary too much, then you're gonna' have a bonafide misfire on your hands.
The next step is to do some math to find out if this low compression value is within a normal parameter or not. Go to: Interpreting Your Compression Test Results.