Testing the engine compression on your 1.6L Honda Civic (Civic del Sol) is a pretty easy and simple affair, since the spark plugs are right on top of the engine. This tutorial will walk you through the entire process in a step-by-step fashion and will also help you interpret your test results.
Contents of this tutorial:
Symptoms Of Low Or No Engine Compression
An engine compression test will help you troubleshoot the root cause of:
- A misfire condition (engine miss, rough idle condition).
- Usually caused by very low compression in one cylinder or...
- Uneven engine compression that varies more than 15% across all 4 cylinders.
- A Cranks but Does Not Start condition.
- Usually caused by no compression on 2 or all 4 cylinders.
I'll go into some detail about these two in the next couple of paragraphs...
Having low or no engine compression in one cylinder on your 1.6L Honda Civic will cause your engine to miss at idle and you'll definitely feel there's something wrong when you accelerate the vehicle.
When this happens (low or no compression on just one cylinder) and your Honda vehicle is OBD II equipped (1996+), you'll see one of the following misfire diagnostic trouble codes:
- P0300: Random Cylinder Misfire.
- P0301: Cylinder #1 Misfire.
- P0302: Cylinder #2 Misfire.
- P0303: Cylinder #3 Misfire.
- P0304: Cylinder #4 Misfire.
If your Honda Civic (Civic del Sol) is NOT OBD II equipped, you won't have any codes lighting up the check engine light, but you'll definitely feel a rough idle condition.
The next common scenario is having low or no engine compression on two ADJACENT engine cylinders and your Honda won't start. It'll Crank but Not Start. This usually indicates that the head gasket has burned between the two cylinders.
If a blown head gasket is a concern, take a look at this tutorial I've written: How To Test For A Blown Head Gasket (Honda 1.6L).
When you have a situation where you have no compression on ALL 4 cylinders, you'll see:
- The engine cranks very fast and this fast cranking speed is very noticeable.
- The Ignition System is sparking all 4 spark plugs, so you know it's not an ignition system problem/issue.
- The fuel injectors spray fuel.
- You can confirm this with a Noid Light test.
- Also, you can confirm this, although indirectly, by removing the spark plugs and checking to see if they are fuel soaked (fuel fouled).
- Fuel pump is working and providing pressure.
- The most common causes of this scenario, are:
- Blown head gasket.
- Broken timing belt.
- Engine thru' a rod.
OK, having covered the most common scenarios of low compression and no compression, let's get testing to see if this is the case on your 1.6L Honda Civic.
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 2: ‘Dry’ Engine Compression Test
If you don't have an engine compression test, you can buy one from your local autoparts store or, if you have an AutoZone or O'Reilly auto parts store nearby, you can rent one from them (they'll rent it for free, after you leave them a cash deposit for the tool, which you'll get back once you return it).
If you need help deciding where to buy one or which one to buy, take a look at my recommendations: Which Compression Tester Should I Buy?
IMPORTANT: You'll be working around a cranking engine, so you have to be careful and stay alert at all times. Think safety all of the time!
IMPORTANT: Do not remove the spark plugs if the engine is hot! If the engine has been running for any length of time, then let it cool down completely before removing the spark plugs.
This is what you'll need to do:
Disable the fuel system. You can do this by disconnecting all of the fuel injectors.
This will prevent fuel from being injected into the engine as you crank the engine.
Disable the ignition system. You can do this by disconnecting the distributor from its electrical connectors.
This will prevent spark from being created and sent to the spark plug wires while cranking the engine. This will also prevent damage to the ignition coil.
Disconnect all of the spark plug wires from the spark plugs.
Remove all four spark plugs.
As your 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).
NOTE: Hand tighten the compression gauge only! Do not use any type of tool to get it tight.
When you're ready, have a helper crank up your Honda as you observe the needle on the compression tester's gauge.
Once the needle on the gauge stops climbing, have him or her stop cranking the engine.
Record this compression reading on a piece of paper. Include the number of the cylinder this reading belongs to.
Repeat steps 5 thru' 8 on the other 3 cylinders.
Let's interpret the results of your compression test
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. For further testing, go to: How To Test For A Blown Head Gasket (Honda 1.6L).
- Broken timing belt. For further testing, go to: How To Test For A Broken Timing Belt (1.6L Honda Civic).
- 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 miles).
But if these values vary too much, then you're gonna' have a bona-fide 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.