How To Test for a Blown Head Gasket (1995-2000 1.8L Mazda Protegé)

Testing for a blown head gasket on your 1.8L Mazda Protegé is not that hard. I can tell you that it's something you can do without having to take your car to the auto repair shop. In this tutorial I am going to show you the 4 different tests that are done to confirm or disconfirm a blown head gasket.

2 of the 4 tests require absolutely no tools. On the remaining 2 tests that require tools, I'm going to show you where to buy them and how to use them.

Contents of this tutorial at a quick glance:

  1. Symptoms of a Blown Head Gasket.
  2. TEST 1: Engine Oil the Color of ‘Coffee With Too Much Cream’.
  3. TEST 2: Coolant Shooting Out From Open Radiator.
  4. TEST 3: Engine Compression Test.
  5. TEST 4: Using a Chemical Block Tester (Combustion Leak Tester).

Symptoms of a Blown Head Gasket

A blown head gasket is almost always the result of severe engine overheating. This severe engine overheating usually has one of three causes:

  1. The radiator fan motor failed and stopped working (and thus stopped cooling the engine).
  2. Engine lost all of the coolant (due to a leak somewhere in the cooling system).
  3. Thermostat went BAD and got stuck closed.

As you're already probably aware, the head gasket's main job is to join the cylinder head to the engine block. In the process, it has to maintain the combustion/exhaust pressures, the engine coolant, and the engine oil separate from each other. So when the head gasket burns (or gets blown), you're going to see one of the following symptoms:

  1. Your 1.8L Mazda Protegé is overheating. You know it's not the fan or thermostat.
  2. White smoke is coming out of the tail-pipe and it smells like anti-freeze being cooked.
  3. The car won't start.
    1. You have already verified it's not an ignition system problem because you have spark coming out at all of the spark plug wires.
    2. You know it's not a lack of fuel, because you have verified that the fuel pump is delivering fuel to the fuel injectors.
  4. The engine oil is thick and tan to off-white color.

TEST 1: Engine Oil the Color of ‘Coffee With
Too Much Creamer’

How To Test for a Blown Head Gasket (1995-2000 1.8L Mazda Protegé)

This is the first of the two tests that don't require any tools to perform. What we're going to do is check the condition of the engine oil.

To be more specific, we want to find out if the engine oil is mixed with coolant. If it is, then the engine oil will be a thick gooey white color (on the dipstick). It will look like ‘coffee with too much creamer’.

If the color of the engine oil is its normal color, on your 1.8L Mazda Protegé, then we'll move on to the next test.

These are the test steps:

  1. 1

    Open your Mazda Protegé's hood and check the condition of the engine oil by pulling out the engine oil dipstick.

  2. 2

    You're gonna' see one of two things:

    1.) The engine oil will be a creamy tan/ off-white color or...

    2.) The engine oil will be its usual normal color.

Alright, let's interpret the color of the engine oil:

CASE 1: The color of the oil is a light tan, like coffee with too much creamer, and your 1.8L Mazda Protegé starts and overheats or does not start. This test result tells you that your 1.8L Mazda Protegé's head gasket is blown.

CASE 2: The color of the engine oil is normal. This the correct and expected test result, but more testing is necessary to make sure the head gasket is not blown (especially if your 1.8L Mazda Protegé is overheating or not starting). Your next step is to go to: TEST 2: Coolant Shooting Out From Open Radiator.