Testing compression on your 2.4L Honda CR-V is pretty easy. What makes this test a breeze, is the fact that removing the spark plugs is a piece of cake.
In this tutorial I'll explain the engine compression test and more importantly, how to interpret your test results so that you can find out if you have any compression issues causing a misfire or a no-start problem.
Contents of this tutorial at a quick glance:
- Symptoms Of Low Or No Cylinder Compression.
- TEST 1: Dry Compression Test.
- Interpreting The Compression Test Results.
- TEST 2: Wet Compression Test.
- Which Compression Tester Should I Buy?
Symptoms Of Low Or No Cylinder Compression
For the most part engine compression problems fall into one of two categories.
In the first category, engine compression problems cause the engine in your 2.4L Honda CR-V to not start. This is usually the result of 0 PSI compression on all 4 cylinders.
In the second category, the engine runs, but it runs with a misfire due to low compression values in one or more cylinders.
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).
- 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).
- Misfire trouble codes set in the computer's memory: P0300, P0301, P0302, P0303, or P0304.
With this info under our belts, let's head down to the next subheading and get testing.
TEST 1: Dry Compression Test
In this first test, we're gonna' test the compression of all four cylinders.
Once we have the values down, in the next section we're gonna' see which of those cylinders we can consider to be dead and causing a problem.
NOTE: It's very important that you remove the spark plugs from a completely cold engine. If you remove the spark plugs from a hot engine, you risk damaging the threads in the spark plug holes (in the cylinder head).
OK, these are the test steps:
Remove the ignition coils sitting on top of the spark plugs.
Remove the spark plugs from a cold engine.
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 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 PSI compression on all 4 cylinders. This test result is usually the result of mechanical damage in the engine.
The most likely cause are:
- 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. The next step is to find out if any of those values is too low and causing a problem.
To find out, go to: Interpreting The Compression Test Results.