Testing the engine compression on the 1991-2001 2.0L equipped CR-V is pretty easy and what makes is so is the fact that removing the spark plugs is easier than on most cars and SUV's out there.
In this tutorial I'm going to explain how to do the compression test and more importantly, how to interpret your test results to find out if the compression of each cylinder is within specification.
Contents of this tutorial:
You can find this tutorial in Spanish here: Cómo Probar La Compresión Del Motor (1997-2001 2.0L Honda CR-V) (at: autotecnico-online.com).
Symptoms of Low or No Cylinder Compression
The majority of engine compression problems fall within two specific categories. The first one is low compression in one or two cylinders causing a misfire condition. The second one is zero or low compression in all cylinders causing the engine to not start.
Here are some of the symptoms you may see when your Honda CR-V has engine compression problems:
- Engine cranks but does not start (0 compression in all cylinders).
- Blue smoke coming out of the tailpipe.
- Rough idle (engine misfires).
- Misfire trouble codes (P0300, P0301, P0302, or P0304) lighting up the check engine light on your CR-V's instrument cluster.
- Bad gas mileage.
- Engine ‘misses’ at idle but ‘miss’ disappears as you accelerate the vehicle.
- 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.
TEST 1: Dry Compression Test
To test the compression of your Honda CR-V engine, you're going to need to remove the spark plugs.
It's extremely important that you do not remove the spark plugs with a hot engine. So if the engine has been running for any amount of time, you need to let the engine cool down completely.
Removing the spark plugs from a hot engine can damage the spark plug threads in the spark plug holes in the cylinder head which is made of aluminum.
OK, these are the test steps:
Disable the ignition system by disconnecting the distributor from its electrical connectors. This will prevent the ignition coil from sparking during the test.
Remove the spark plugs from a slightly warmed up engine (if it starts and runs). 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.
If the engine does not start, don't worry about it being warmed up.
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 repeat this step 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: You got 0 compression on all 4 cylinders. This test result is usually due to one of the following conditions:
- Timing belt problem.
- Blown head gasket.
- Blown engine.
Any compression value below 100 PSI (even if it doesn't go down to 0 PSI) means internal mechanical engine trouble.
CASE 2: You got uneven compression values between engine cylinders. To a certain extent, uneven compression values might be normal if the engine has a lot of miles.
The next step now is to find out if your compression test results are within normal operating parameters. For this info go to: Interpreting The Compression Test Results.