How To Test For A Blown Head Gasket (Ford 2.3L)

If your 2.3L Ford Ranger or 2.3L Ford Mustang has overheated and it won't start... there's a good chance you have a blown head gasket on your hands.

This is because the most common end result of severe over-heating is usually a blown head gasket, but not always. That's right... a blown head gasket is not an absolute truth when your 2.3L Ford Ranger or Mustang overheats.

If and when a head gasket burns or the cylinder head warps, there are 3 specific things that you can check to find out:

  1. Check to see if the engine oil is mixed with coolant.
  2. Check to see if exhaust/compression gases and pressures escaping thru' the cooling system.
  3. Check to see if cylinder compression is escaping from one cylinder into the adjacent one and vice-versa.

In this article, I'll show you what to look for and what to test so that you can confirm that you do indeed have a blown head gasket issue or not.

Here are the main points of this article:

  1. Symptoms of BAD Engine Compression.
  2. TEST 1: Engine 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 Puedes encontrar este tutorial en Español aquí: Cómo Probar un Empaque de Cabeza Quemado (2.3L Ford) (en: autotecnico-online.com).

Symptoms Of A Blown Head Gasket

At the beginning of the article, I touched on three specific symptoms of a blown head gasket.. but there are a couple more symptoms you could be seeing in your 2.3L Ford Ranger or 2.3L Ford Mustang and they are:

  1. Your Ford Starts and Runs but Overheats.
    1. You may have already checked and/or replaced:
      1. Thermostat.
      2. Water pump.
      3. Radiator.
      4. Repaired any coolant leaks.
      5. Fan clutch.
      6. Fan motor.
  2. Oil mixed with coolant.
    1. This causes the engine oil to look like ‘coffee with too much cream’.
    2. No matter how many times the oil gets changed, it immediately turns into this creamy white color.
  3. If your Ford starts and runs, you have white smoke coming out of the tail-pipe.
    1. If you're using anti-freeze, you'll smell its sweet smell in the smoke.
  4. Engine cranks, but does not start.
    1. When this happens, you'll notice that everything works, for example:
      1. Fuel pump.
      2. COP coils.
      3. Fuel injectors.
      4. Timing belt is OK.
  5. No compression on two side by side cylinders.

TEST 1: Engine Oil Mixed With Coolant

Engine Oil Mixed With Coolant. How To Test For A Blown Head Gasket (Ford 2.3L)

The cylinder head gaskets on your 2.3L Ford Mustang or 2.3L Ford Ranger (or 2.3L Mazda B2300) are tasked with keeping three very specific components of the engine separate from one another (among several things) and these three are:

  1. Coolant.
  2. Engine oil.
  3. Compression/combustion pressures and gases.

When your vehicle overheats to the point that the aluminum cylinder head warps and/or the head gasket burns... these components will mix.

The most common end result of a blown head gasket is coolant mixing with the engine oil. To check for this, all you have to do is:

  1. Open the hood of the car.
  2. Pull out the engine oil dipstick.
  3. Check the color of the oil sticking to the dipstick.
  4. You'll see one of two things:
    1. The color of the oil will be a milky white color (like coffee with too much cream).
    2. Or the color of the oil will be its normal color.

Let's take a look at your test result:


CASE 1: The engine oil was a milky white color (like coffee with too much cream). This is BAD news and confirms that you do have a blown head gasket on your 2.3L Ford Ranger or 2.3L Ford Mustang.

CASE 2: The engine oil was its normal color. This doesn't confirm anything just yet. You'll need to go to the next test to make sure. Go to TEST 2: Coolant Shooting Out Of Radiator.