This tutorial will help you find out if the head gasket is blown on your 2.4L equipped GM vehicle.
Testing for blown head gasket isn't hard. For the most part there are four tests involved.
Two of those four tests involve no tools at all. The other two, that do you require tools, are a compression test and a block test. All four tests are explained in detail.
NOTE: This tutorial applies to the following 2.4L equipped GM vehicles:
- Chevrolet Cobalt 2.4L: 2006, 2007, 2008
- Chevrolet HHR 2.4L: 2006, 2007, 2008, 2009
- Chevrolet Malibu 2.4L: 2008, 2009, 2010, 2011, 2012
- Pontiac G5 2.4L: 2006, 2007, 2008
- Pontiac G5 GT 2.4L: 2007, 2008
- Pontiac G6 2.4L: 2006, 2007, 2008, 2009
- Pontiac Soltice 2.4L: 2006, 2007, 2008, 2009
Contents of this tutorial at a glance:
Symptoms Of A Blown Head Gasket
A blown head gasket can cause one of several symptoms. But they usually fall into one of two categories.
In the first category the blown head gasket causes the 2.4L four cylinder engine in your GM vehicle to crank but not start.
In the second category, the engine starts but it overheats. Besides the engine overheating you're going to see one or more of the following 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.
Another very common problem of the head gasket that used on the 2.4L GM engine is the fact that it has a propensity to start leaking oil.
The head gasket on the 2.4L GM engine is a multi-layered steel head gasket. This type of gasket is infamous for developing engine oil leaks sooner or later.
With this type of head gasket it doesn't matter how well you maintain the engine, the head gasket is going to fail sooner or later and cause engine oil to leak from it.
TEST 1: Engine Oil The Color Of Coffee With Too Much Creamer
The most common symptom of a blown head gasket is coolant mixing with the engine oil in the crankcase.
This causes the engine oil to have a color that looks like coffee with too much creamer.
We can easily check the condition / color of the oil by simply pulling out the engine oil dipstick and checking what color the oil has that sticking to it.
And this will be our first test.
These are the test steps:
Open the hood on your vehicle.
Remove the engine oil dipstick.
What color is the engine oil?
1.) Is it a creamy tan/off-white color that looks like coffee with too much creamer.
2.) The engine oil will be its usual normal color.
Let's examine your test results:
CASE 1: The engine oil sticking to the dipstick has a normal color. This is the correct and expect a test result.
The next test is to remove the radiator cap and then crank the engine to see if the engine coolant will be shot out. 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 the head gasket on your 2.4L Chevrolet Cobalt is blown.