Blown Head Gasket Tests (1992-2011 4.6L Crown Victoria, Grand Marquis)

There are four tests you can perform to find out if your Ford Crown Victoria or Mercury Grand Marquis has a blown head gasket issue.

The other two are the compression test, which requires an engine compression tester, and the block test, which uses a chemical combustion leak detector."

In this tutorial, I’ll show you how to perform all four tests to determine if your Crown Vic (Grand Marquis) has a blown head gasket.

This tutorial applies to the following vehicles:

• 4.6L Ford Crown Victoria: 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011.
• 4.6L Mercury Grand Marquis: 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011.

Symptoms Of A Blown Head Gasket

For the most part, cylinder head gasket failures will cause one of two problems:.

• Engine No-Start: When one or both head gasket fail, they can cause the engine to not start.
• Engine Starts But Overheats Within Minutes: Almost as soon as the engine starts, it overheats. Many times it seems to overheat for no apparent reason.

Here's a basic list of the symptoms you're going to see when your Crown Vic (Grand Marquis) suffers a head gasket failure:

• The engine overheats for no apparent reason. All engine cooling system components (like fan motor, water pump, etc.) are working fine.
• White smoke is coming out of the tail-pipe and it smells like anti-freeze being cooked.
• 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

The most frequent problem encountered when one or both head gaskets fail on your Crown Vic (Grand Marquis) is coolant entering the engine crankcase and mixing with the engine oil.

The end result is the mixture of engine oil and coolant looking like 'coffee with too much creamer' (in other words: a 'milky-white' mixture).

For our first test, we’ll check the color and viscosity of the oil on the engine oil dipstick.

If the oil resembles coffee with too much creamer, you've got a blown head gasket. If the oil looks normal (as in not milky-white), we'll move on to the next test.

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 Crown Vic (Grand Marquis).

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.

TEST 2: Coolant Shooting Out From Open Radiator

The second most common test to check for a blown head gasket, which doesn’t require any tools, involves observing if engine coolant is expelled from the coolant expansion tank (with its cap removed) while the engine is cranking.

If coolant is forcefully expelled from the open expansion tank while cranking the engine, it indicates your Crown Vic (Grand Marquis) has a blown head gasket.

Normally (no blown head gasket issue), the coolant should remain undisturbed within the open expansion tank as the engine is cranked.

IMPORTANT: Do not remove the cap from the coolant expansion tank if the engine is hot or has been running for any length of time. Let the engine cool down completely before removing the cap from the radiator.

Let's get started:

1. 1

   Remove the coolant expansion tank's cap.
   
   Check the coolant level and if necessary add some water or coolant.

2. 2

   Have your helper crank the engine while you stand at a safe distance from the open coolant expansion tank.

3. 3

   You'll see one of two results:
   
   1.) The water or coolant inside the tank will shoot out.
   
   2.) The coolant remained undisturbed. In other words, cranking the engine will have no effect on the level of the water or coolant in the coolant expansion tank.

Let's examine your test result:

CASE 1: The coolant shot out from the expansion tank as you cranked the engine. This confirms that one or both head gaskets are blown on your Crown Vic (Grand Marquis).

CASE 2: The coolant DID NOT shoot out from the expansion tank. This is the correct and expected test result.

If the engine, in your Crown Vic (Grand Marquis), starts but runs with a misfire, then next step is to test engine compression. For this test go to: TEST 3: Engine Compression Test.

If the engine starts but overheats almost immediately, then your next step is to do a 'block' test. For this test go to: TEST 4: Using A Chemical Block Tester (Combustion Leak Tester).