How To Test A Blown Head Gasket (3.4L V6 Buick, Oldsmobile)

TEST 4: Using A Chemical Block Tester (Combustion Leak Tester)

In some cases the engine has a head gasket failure, yet you're not going to see any of the three symptoms that the other three tests are designed to confirm as a blown head gasket.

To be a bit more specific, you're NOT going to see:

• The engine oil mixed with coolant.
• The coolant being shot out of the radiator as the engine is being cranked.
• Two side-by-side cylinders with 0 PSI compression.

In these cases, the only way to find out if your engine has a blown head gasket failure, is to do a combustion leak tester test. This test is commonly known as a block test.

This is how the combustion leak detector test (block test) works:

• The combustion leak detector tester is filled with a blue liquid chemical (see photo above).
• The radiator cap is removed (you may have to drain some of the coolant in the radiator since this tool needs to ‘gulp’ some of the air inside the radiator).
• The engine is started.
• The tester is then placed on the open radiator neck.
• The rubber bellow is then squeezed to suck in the air up through the two fluid-filled chambers. As the air bubbles up through the fluid, it will cause a chemical reaction.
• If the blue chemical turns yellow (for gasoline engines), then combustion gases are entering the radiator. This in turn confirms a blown head gasket, a cracked block, or a cracked cylinder head issue.
• If the blue chemical doesn't change color, then you can conclude that you don't have a blown head gasket, a cracked block, or cracked cylinder head issue.

You can shop for a block tester here:

More 3.4L V6 Buick, Oldsmobile Tutorials

You can find a complete list of 3.4L V6 Buick (Oldsmobile) tutorials in this index:

• GM 3.4L Index Of Articles.

Here's a small sample of the tutorials you'll find in the index:

• How To Test Engine Compression Test (3.4L V6 Buick, Oldsmobile).
• How To Test The MAF Sensor (3.4L V6 Buick, Oldsmobile).
• What Does The CKP Sensor Do? (3.4L V6 Buick, Oldsmobile).
• How To Test The Throttle Position Sensor (3.4L V6 Buick, Oldsmobile).