Testing the engine compression on your Suzuki Sidekick's (or Geo/Chevy Tracker's) 1.6L 4 cylinder engine is pretty easy.
In this tutorial, I'll show you how to do and interpret the results of your ‘Dry’ and ‘Wet’ engine compression test results.
Contents of this tutorial:
Important Tips And Suggestions
TIP 1: If your 1.6L Sidekick's engine starts and runs, it's a good idea to let it warm up for about 15 minutes (before starting the compression test). I want to emphasize the key words: ‘slightly warmed up engine’ since it should not be hot.
Why warm up the engine? Because a slightly warmed up engine will improve the accuracy of your compression test results.
TIP 2: Take all necessary safety precautions as you work around a cranking engine. Use common sense and think safety all of the time.
TIP 3: The cylinder head, on your Suzuki, is made of aluminum so you should never remove the spark plugs if the engine is hot (hot = normal operating temperature). Removing the spark plugs from a hot engine can/will damage the spark plug hole threads in the aluminum cylinder head.
Symptoms Of Low Or No Cylinder Compression
Engine compression problems fall into 2 basic categories: Low engine compression in one or two cylinders and no compression in all cylinders.
When your Sidekick (Tracker) suffers from low engine compression, the engine will run but run rough and/or misfire.
When your Sidekick's engine has no compression in all cylinders, the engine will ‘crank but not start’.
Here are some other specific symptoms you may see with low cylinder compression:
- If OBD II equipped, you'll have one or more of the following misfire diagnostic trouble codes: P0300, P0301, P0302, P0303, P0304.
- Engine cranks but does not start (0 compression in all cylinders).
- Blue smoke coming out of the tailpipe.
- Rough idle (engine misfires).
- Bad gas mileage.
- Engine ‘misses’ at idle but ‘miss’ disappears as you accelerate.
- Check engine light is illuminated with a MAP sensor trouble code (even tho' the MAP sensor is good).
With this info under our belts, let's head down to the next subheading and get testing.
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 Compression Test
You'll need to remove the spark plugs for the engine compression test and this will afford you the chance to see if the spark plug wire boots and spark plugs are swimming in motor oil (from leaking valve cover gaskets).
Leaking valve cover gaskets that are letting the spark plug tubes fill up with motor oil are a very common problem on the 1.6L engines. This problem will eventually result in a misfire condition as the oil cooks and creates carbon tracks on the spark plug or spark plug boot.
So, if you do spot a spark plug wire boot covered/dripping in oil, then you've found a the potential problem behind the misfire you're trying to diagnose with the compression test (you should still proceed with the compression test though).
OK, to get started this is what you'll need to do:
Disable the ignition system by disconnecting the ignition distributor from its electrical connector.
This will prevent the ignition coil from sparking during the test.
Remove the spark plugs. Remember, the engine can not be hot!
When removing the spark plugs, be careful not to drop any of them on the floor, or you run the risk of having the spark plugs porcelain insulator crack and then you'll have a misfire on your hands.
Thread the engine compression gauge into the spark plug hole for the number 1 engine cylinder.
Hand tighten the compression gauge only! Do not use any type of tool to get it tight.
Have your helper crank the engine till the needle on the compression gauge stops climbing.
Now, record on paper the value at which the needle stopped and the number of the engine cylinder on a piece of paper.
Release the pressure on the gauge and test the cylinder's compression one more time.
Repeat this test step on the remaining 3 cylinders.
Let's take a look at what your test results mean:
CASE 1: Low or no compression in 2 or all 4 cylinders. This test result indicates a serious internal problem.
The most common issues would be:
- Blown head gasket.
- To further test this, I recommend the following tutorial: How To Test For A Blown Head Gasket (1.6L Suzuki Sidekick, Geo Tracker).
- Broken timing belt.
- Engine threw a rod.
CASE 2: Low compression in one or more cylinders. To a certain point, it's normal for the compression to vary a little between cylinders (as the engine accumulates thousands of miles).
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.