How To Test For A Blown Head Gasket (1993-2002 2.5L Dodge Dakota)

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

Using a block tester is the most accurate way (of the previous three tests) to check for a hard to diagnose blown head gasket.

By a 'hard to diagnose blown head gasket' I mean one where the previous three tests weren't able to confirm that the head gasket is blown. Usually in these types of cases, your Dodge Dakota's engine overheats for no apparent reason.

You can buy a block tester in just about any auto parts store. In a nutshell, this is how a block tester works:

• A blue liquid chemical, which is blue in color, is placed in the tester (see photo above).
• The tester assembly is then placed on the open radiator neck (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 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 result 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 a cracked cylinder head issue.

Where can you get the chemical and block tester? At your local auto parts store or here:

More 2.5L Dodge Dakota Tutorials

You can find a complete list of tutorials here: Chrysler 2.5L 4-Cylinder Index Of Articles.

Here's a sample of the tutorials you'll find there:

• Oxygen Sensor Heater Test (1993-1995 2.5L Dodge Dakota).
• How To Test The TPS (1993-1995 2.5L SOHC Dodge Dakota).
• How To Test The MAP Sensor (1994-1995 2.5L SOHC Dodge Dakota).
• How To Test Engine Compression (1993-2002 2.5L Dodge Dakota).