TEST 4: Using A Chemical Block Tester (Combustion Leak Tester)
Unfortunately, a head gasket can fail and yet the engine starts and runs but overheats after a few minutes.
Usually, in these cases, the engine oil isn't mixed with coolant and the compression gases are not escaping into the cooling system.
This also means that the head gasket failure can not be pin-pointed by the 3 previous tests. The test of last resort, is a block test with a combustion leak detector.
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 thus confirming a head gasket, a cracked blocked, or cracked cylinder head issue.
- If the blue chemical doesn't change color, then you can conclude that you don't a head gasket, a cracked blocked, or cracked cylinder head issue.
You can shop for a block tester here:
More 3.3L Chrysler, Dodge, And Plymouth Mini-Van Tutorials
You can find a complete list of tutorials in this index: Chrysler 3.3L Index Of Articles.
- How To Test The MAP Sensor (2001-2004 3.3L V6 Chrysler And Dodge Mini-Van).
- How To Test The Alternator (2001-2007 3.3L Chrysler).
- How To Test Engine Compression (1991-2007 3.3L V6 Chrysler, Dodge, Plymouth Mini-Van).
- How To Test The Coil Pack 3.3L, 3.8L Chrysler, Dodge, Plymouth (at: easyautodiagnostics.com).
If this info saved the day, buy me a beer!