There are 4 tests that are done to confirm a blown head gasket and in this tutorial, I'm going to explain how to do them.
With your test results you'll be to find out if you have a blown head gasket (or not) on your GM vehicle equipped with a 3.9L V6 engine.
The vehicles covered by this tutorial, that are 3.9L V6 equipped are: 2006-2010 Chevrolet Impala, 2006-2007 Chevrolet Malibu, 2006-2008 Chevrolet Uplander, 2006-2009 Pontiac G6, and 2006-2009 Pontiac Montana.
Contents of this tutorial at a glance:
You can find this tutorial in Spanish here: Cómo Probar Los Empaques De Cabeza (2006-2010 3.9L V6 GM) (at: autotecnico-online.com).
Symptoms Of A Blown Head Gasket
From personal experience I can tell you that head gasket problems usually cause one of two different types of problems.
In the first type, a blown head gasket will cause your 3.9L V6 equipped GM vehicle to crank but not start.
In the second type of blown head gasket failure, the engine will start and run but it will overheat almost immediately and for apparently no reason at all.
As you're probably already aware, the 3.9L V6 engine has two cylinder heads. This means that it has two cylinder head gaskets.
When one or both of them fail you're going to see one of several symptoms.
- The exhaust smells like antifreeze being burned.
- White smoke comes out of the tailpipe as soon as the engine starts and runs.
- A rough idle condition usually accompanied by a P0300 misfire trouble code.
- Specific misfire cylinder codes like: P0301, P0302, P0303, P0304, P0305, or P0306.
- A lack of power when you accelerate the vehicle.
TEST 1: Engine Oil The Color Of Coffee With Too Much Creamer
One of the most common end results of a blown head gasket is engine coolant mixing with the engine oil in the crankcase.
This turns the engine oil the color of coffee with way too much creamer.
Testing to see if this has happened is super easy since all we have to do is to check the color of the oil sticking to the engine oil dipstick. And this is the very first test we're going to do.
If the color of the engine oil, sticking to the dipstick, is OK then we'll move on to the next test.
These are the test steps:
Open the car engine's hood and pull out the engine oil dipstick.
What you're looking for is to make sure that the engine oil IS NOT mixed with coolant. If the engine oil is mixed with coolant, it'll be the color of 'coffee with too much cream'.
What color is the engine oil?
1.) The engine oil is a creamy tan/off-white color.
2.) The engine oil is its usual normal color.
Let's examine your test results:
CASE 1: The engine oil sticking to the dipstick has a normal color. So far so good but we're not out of the woods yet. The next step is to see if the coolant is being pushed out of the coolant reservoir while we crank the engine. For this test go to: TEST 2: Coolant Shooting Out From Opened Radiator.
CASE 2: The oil sticking to the dipstick looks like coffee with way too much creamer. This test result confirms that one or both head gaskets are blown on your 3.9L V6 Chevy Malibu (Impala, Uplander, G6, or Montana).