How To Test A GM 4.3L, 5.0L, 5.7L Blown Head Gasket

There are several ways to test for a blown head gasket and in this article I'm gonna' show three of the most common.

Two of these tests involve no tools what-so-ever and the third involves a compression tester (and thus a compression test) and the fourth a handy tool called a combustion leak tester (commonly known as a block tester).

Here are the main points of this article:

  1. Symptoms of BAD Engine Compression.
  2. TEST 1: Engine Oil 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
  7. Related Test Articles.

Symptoms Of A Blown Head Gasket

There are several symptoms and if the head gasket is blown on your Suzuki vehicle, you'll definitely see at least one or two of them:

  1. Overheating.
  2. Oil Mixed with Coolant.
  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.

TEST 1: Engine Oil Mixed With Coolant

Checking to See if the Oil is Mixed with Coolant (GM 4.8L, 5.3L, 6.0L Blown Head Gasket Test)

One of the most important functions, of the cylinder head gasket, is to keep three very specific components of the engine separate from one another and they 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 interpret your test result:

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.