How To Test For A Blown Head Gasket (1988-1993 2.8L Chevrolet S10 Pickup, GMC S15 Pickup, GMC Sonoma)

There are four specific methods to test for a blown head gasket. So if you suspect your Chevy S10 pickup (GMC S15 pickup, GMC Sonoma) 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 at all, the third involves a compression tester and the fourth involves a handy tool called a combustion leak tester (commonly known as a block tester).

You can find this tutorial in Spanish here: Cómo Probar Un Empaque De Cabeza Quemado (2.8L V6 S10/S15) (at: autotecnico-online.com).

• 2.8L Chevrolet S10 Pickup: 1988, 1989, 1990, 1991, 1992, 1993.
• 2.8L GMC S15 Pickup: 1988, 1989, 1990.
• 2.8L GMC Sonoma: 1991, 1992, 1993.

This tutorial also applies to the 2.8L Chevy S10 Blazer, 2.8L GMC S15 Jimmy. See the 'Applies To' box on the left column (desktop) or at the bottom of the page (mobile device) for more info.

Symptoms Of A Blown Head Gasket

Severe engine overheating can often result in a blown head gasket in your 2.8L V6 S10/S15 pickup, which comes equipped with two. Failure of one or both head gaskets can result in several symptoms.

If your vehicle does indeed have a blown head gasket, you'll likely observe at least one or two of the following symptoms.

• Overheating.
• Oil Mixed with coolant.
• White smoke coming out of the tail-pipe.
• Engine cranks, but does not start.
• No compression on two side by side cylinders.

TEST 1: Engine Oil Mixed With Coolant

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

So for our first step, in diagnosing a blown head gasket, we'll check the color of the engine oil on the dipstick.

No tools are required for this test and the entire process can be completed in just a few minutes.

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:
   
   1.) The color of the oil will be a milky white color.
   
   2.) 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. So far so good, but we're not out of the woods yet.

You'll need to go to the next test to make sure. Go to: TEST 2: Coolant Shooting Out Of Radiator.