How To Test for a Blown Head Gasket (4.2L Ford E150, E250, F150)

You can test for the head gasket yourself since the tests are not hard to do.

So, if your 4.2L Ford F150 (4.2L E150 or 4.2L E250) has suffered severe over-heating and you suspect you have a blown head gasket on your hands... this tutorial will explain the most common blown head gaskets test that are done.

Here are the main points of this article:

  1. Symptoms of BAD Engine Compression.
  2. TEST 1: Motor Oil Looks Like ‘Coffee With Too Much Cream’.
  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
  7. More Ford 4.2L Tutorials

En Español Puedes encontrar este tutorial en Español aquí: Cómo Probar el Empaque de Cabeza (4.2L Ford F150, E150, E250) (en: autotecnico-online.com).

Symptoms Of A Blown Head Gasket

In the vast majority of cases a blown head gasket is the end-result of the engine severely overheating.

There are several symptoms and if the head gasket is blown on your 4.2L Ford F150 (4.2L E150 or 4.2L E250), you'll definitely see at least one or two of them:

  1. Overheating.
  2. Oil mixed with coolant (which looks like ‘coffee with too much cream’).
  3. White smoke coming out of the tail-pipe.
  4. Engine cranks, but does not start.
  5. No compression on two side by side cylinders.

Let's get testing...

TEST 1: Motor Oil Looks Like ‘Coffee With Too Much Cream’

Checking to See if the Oil is Mixed with Coolant (4.2L Ford E150, E250, F150)

As you're already aware, part of the head gasket's job is to keep the oil and coolant (flowing thru' the oil and coolant passages in the block and heads) from mixing together.

So, when a head gasket or gaskets get blown... the most common end result is coolant mixing with the engine oil.

Since checking for this is one of the easiest test to do... we'll start with it first.

These are the steps:

  1. 1

    Open the hood of your 4.2L Ford pickup (or van).

  2. 2

    Pull out the engine oil dipstick.

  3. 3

    Check the color of the oil sticking to the dipstick.

  4. 4

    You'll see one of two things: The color of the oil will be a milky white color or the color of the oil will be its normal color.

Let's take a look at your test results:


CASE 1: The engine oil was a milky white color. This tells you that the coolant is mixing with the Oil and that you do have a blown head gasket on your hands.

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.