How To Test for a Blown Head Gasket (2.8L V6 S10/S15)

There are 4 specific ways to test for a blown head gasket. So, if you suspect that your Chevy S10 (or GMC S15) has a blown head gasket... this tutorial will show you how to test for a blown head gasket (just like they do at the auto repair shop).

Two of these tests involve no tools what-so-ever , 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. More GM 2.8L Tutorials

En Español Puedes encontrar este tutorial en Español aquí: Cómo Probar un Empaque de Cabeza Quemado (2.8L V6 S10/S15) (en: autotecnico-online.com).

Symptoms of a Blown Head Gasket

A blown head gasket is usually the result of severe engine over-heating.

There are several symptoms and if the head gasket is blown on your 2.8L V6 S10/S15, 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 (2.8L V6 S10/S15)

The most common end result of a blown head gasket is coolant mixing with the engine oil.

So, the very first thing we'll check, to diagnose a blown head gasket, is the color of the motor oil on the engine dipstick.

These are the steps:

  1. 1

    Open the hood of your Chevrolet S10 or GMC S15.

  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.