How To Test A Blown Head Gasket (1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 4.0L V6 Ford Ranger And Mazda B4000)

Confirming that your 4.0L Ford Ranger (Mazda B4000) has a blown head gasket problem is not difficult.

In this tutorial, I'll explain four easy tests you can perform to determine if you have a blown head gasket issue on your hands. You'll find all of the tests presented in a step-by-step manner and in plain English.

NOTE: You can find the 4.0L Ford Explorer (Aerostar and Mercury Mountaineer) blown head gasket tests here:

APPLIES TO: This tutorial applies to the following vehicles:

  • 4.0L V6 Ford Ranger: 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011.
  • 4.0L V6 Mazda B4000: 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009.

Symptoms Of A Blown Head Gasket

Over the years I've been wrenching on cars, I've noticed that blown head gasket problems usually cause one of two issues:

  • An engine no-start problem.
  • The engine starts and runs, but it overheats almost immediately.

If the engine starts and runs but has a blown head gasket, you'll see one or more of the following symptoms:

  • The engine overheats for no apparent reason. All engine cooling system components (fan motor, water pump, etc.) are working fine.
  • White smoke is coming out of the tail-pipe, and it smells like burning anti-freeze.
  • The engine won't start.
  • The engine oil is thick and a milky white color.

TEST 1: Engine Oil The Color Of ‘Coffee With Too Much Creamer'

Engine Oil The Color Of Coffee With Too Much Creamer. How To Test A Blown Head Gasket (1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 4.0L V6 Ford Ranger And Mazda B4000)

The most common symptom of a blown head gasket is coolant mixing with the engine oil in the crankcase.

This condition results in engine oil that looks like coffee with too much creamer.

You can easily confirm if this has happened in your 4.0L V6 Ford Ranger by checking the condition of the oil sticking to the engine oil dipstick.

Let's get started:

  1. 1

    Open the hood.

  2. 2

    Pull out the engine oil dipstick.

  3. 3

    Check the color of the oil sticking to the engine oil dipstick.

  4. 4

    You'll see one of two results:

    1.) The engine oil looks like coffee with too much creamer.

    2.) The engine oil is its usual normal color.

Alright, let's analyze your test result:

CASE 1: The engine oil has the color of coffee with too much creamer. This test result confirms that one or both head gaskets are blown on your 4.0L Ford Ranger (Mazda B4000).

CASE 2: The color of the engine oil is normal. This is the correct and expected test result.

The next test is to see if the engine's compression pressures are escaping into the engine's cooling system (radiator). For this test go to: TEST 2: Coolant Shooting Out From Open Radiator.

Ford Vehicles:

  • Ranger 4.0L
    • 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011

Mazda Vehicles:

  • B4000 4.0L
    • 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009