How To Test For A Blown Head Gasket (1.5L Honda Civic)

When your 1.5L Honda Civic overheats and the head gasket gets blown, you'll see some very specific symptoms. It's these symptoms, that will confirm the head gasket is blown.

In this tutorial, I'll show you the 4 most common tests done to check for a blown head gasket.

Here are the main points of this article:

  1. Symptoms Of A Blown Head Gasket.
  2. TEST 1: Engine Oil Mixed With Coolant.
  3. TEST 2: Coolant Shooting Out of Radiator.
  4. TEST 3: Engine Compression Test.
  5. TEST 4: Using A Chemical Block Tester (Combustion Leak Tester).
  6. Frequently Asked Questions.

En Español You can find this tutorial in Spanish here: Cómo Verificar un Empaque de Cabeza Quemado (1.5L Honda Civic) (at: autotecnico-online.com).

Symptoms Of A Blown Head Gasket

There are several symptoms, that you'll see when the head gasket gets blown on your 1.5L Honda Civic. Depending on how bad the head gasket is, your Civic will either not start or start and overheat.

Here's a basic list of what you may see if your Civic has a blown head gasket:

  1. Overheating.
  2. Oil Mixed with Coolant.
  3. White smoke coming out of the tail-pipe.
  4. Engine cranks, but does not start.
  5. No compression on two adjacent cylinders.
  6. Coolant being pushed forcibly into the coolant reservoir bottle whenever the engine idles or the engine is turned off.

If your 1.5L Honda Civic starts and runs, but overheats and you have already checked and confirmed that the water pump, the thermostat, the radiator fan motors are OK... then there's a good chance you have a blown head gasket on your hands. The following 4 tests will help find out.

TEST 1: Engine Oil Mixed With Coolant

How To Test For A Blown Head Gasket (1.5L Honda Civic)

Whenever I was given a ‘car overheats, possible blown head gasket’ or a ‘car doesn't start after overheating’ to diagnose, the first thing I would do was check to see if the car's engine oil was mixed with coolant.

Why? Because this is usually the most common end-result of a blown head gasket. In my personal experience, about 90% of the vehicles diagnosed with a bona-fide blown head gasket had this ‘engine oil mixed with coolant’ condition.

This is a very easy and simple test. This is what you have to do:

  1. 1

    Open the hood of the car and pull out the engine oil dipstick.

  2. 2

    Check the color of the oil sticking to the dipstick.

    You'll see one of two things: The color of the oil will be a milky white color (like coffee with too much cream) -OR- the color of the oil will be its normal color.

Let's take a look at what your test results mean:


CASE 1: The engine oil was a milky white color. This tells you that the coolant is mixing with the engine oil as a result of a blown head gasket.

CASE 2: The engine oil was its normal color. So far so good. You're not out of the woods yet, your next step is to see if the head gasket is leaking cylinder compression pressure into the cooling system.

For this test go to TEST 2: Coolant Shooting Out of Radiator.