Testing a Blown Head Gasket (Ford 4.9L, 5.0L, 5.8L)

In this article, I'll shed some light on the four most common tests that check for a blown head gasket.

One of the biggest symptom you'll see, when you've got a blown head gasket on your hands, is that your Ford van, pick up, or car will overheat.

This in itself does not prove a blown head gasket and so, to make sure, I'll show you 4 different ways to see if your Ford vehicles does have or doesn't have a blown head gasket issue. Three of the tests I'm gonna' show you, you can do in less than 10 minutes. Two of them require absolutely no tools.

To make it easier to navigate this article, here are its contents at a quick glance:

  1. Symptoms of a Blown Head Gasket.
  2. TEST 1: Oil the Color of ‘Coffee with too Much Cream’.
  3. TEST 2: Exhaust Shooting out of the Radiator.
  4. TEST 3: Engine Compression Test
  5. TEST 4: Using a Chemical Block Tester (Combustion Leak Tester).
  6. Is the Cylinder Head Cracked?
  7. More Ford 4.9L, 5.0L, 5.8L Tutorials.

En Español You can find this tutorial in Spanish here: Cómo Probar un Empaque de Cabeza Quemado (4.9L, 5.0L, 5.8L Ford) (at: autotecnico-online.com).

Symptoms of a Blown Head Gasket

The most common cause of a blown head gasket is that the engine overheated because: 1) Fan clutch is not working, 2) All of the coolant leaked out of the engine and you kept driving it this way. 3) Thermostat went BAD and is stuck closed and the coolant could not circulate. The most common symptoms a blown head gasket are:

  1. Your 4.9L, 5.0L, 5.8L Ford van (pick up, car, SUV) is overheating. You know it's not the Fan (or Fan Clutch) or Thermostat.
  2. White smoke is coming out of the tail-pipe and it smells like anti-freeze being cooked.

  3. Your Ford van (car, pick up, SUV) 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 (mixed with coolant).

TEST 1: Oil the Color of ‘Coffee with too Much Cream’

Oil the Color of ‘Coffee with too Much Cream’. Testing a Blown Head Gasket (Ford 4.9L, 5.0L, 5.8L)

The coolant, the engine oil and the exhaust gases (to name a few things) must be kept seperated from one another as they travel between the block and the cylinder head.

As you may already know, the head gasket is tasked with the job of sealing all of these so that they don't mix. But when the head gasket or gaskets get burned (due to extreme overheating)... things are gonna' mix.

So the very first thing you'll do is to see if coolant is mixing with the engine oil.

OK, I'll stop talking and we'll get this show on the road... this is what you need to do:

  1. 1

    Pop the hood on your Ford 4.9L, 5.0L, 5.8L car (van, pick up, SUV) and once open, pull out the engine's oil dipstick.

  2. 2

    Now, check what the color of the oil is and how thick it is. You'll see one of two things:

    1.) Either the oil on the dipstick is a creamy, off-white color and is thick as syrup Or...

    2.) The oil is its normal color and viscosity.

Now, let's find out what each of the two results mean:

CASE 1: The color of the oil is a light tan, like coffee with too much cream, this is BAD news and tells you without a shadow of a doubt that you do have a blown head gasket.

Why does the oil look like this? Mainly because your Ford pick up (van, car, SUV) severly over-heated and :

  1. The cylinder head warped and/or cracked. This warping/cracking leads to the head gasket burning.
  2. Once the head gasket stops sealing and separating the engine oil, coolant, and exhaust gases... they will all mix.
  3. The end result is coolant entering the oil passages of the engine block and then into the engine oil pan.
  4. As both oil and coolant mix... the resulting combination gets thick and becomes an off-white color.

CASE 2: The color of the engine oil is normal, So far so good, the next step is to check to see if compression/exhaust gases are leaking into the cooling system. Go to TEST 2: Exhaust Shooting out of the Radiator.

Here's why: Normally (about 90% of the time) when a head gasket gets blown on a Ford van (pick up, SUV)... coolant will enter into the crankcase and mix with the engine oil. But not always so the next test is to see if the engine's compression/ combustion gases are escaping thru' the radiator.