TEST 2: Exhaust Gases Shooting Out Of The Radiator
If you've reached this point, then the engine oil sticking to the dipstick looks normal. In this test section we're going to remove the radiator cap and then crank the engine.
If the coolant gets shot out of the radiator, then you can conclude that one or both of the head gaskets are blown.
Now, if the coolant remains undisturbed in the radiator, as you crank the engine, then the engine has passed this test with flying colors. Your next step is to go to TEST 3.
CAUTION: Do not remove the radiator cap from the radiator if the engine is hot. If the engine has been running for any length of time, then let it cool down completely before removing the radiator cap!
These are the test steps:
- 1
Remove the radiator cap from the radiator.
If the radiator is not full, then top it off with water. - 2
Have your helper to crank the engine, while you stand at a safe distance from the open radiator.
- 3
You'll see one of two results:
1.) The water or coolant inside the radiator will shoot up and out of the now open radiator.
2.) The coolant will not be disturbed. In other words, cranking the engine will have no effect on the level of the water or coolant in the radiator.
Let's examine your test result:
CASE 1: The coolant bubbled out or shot out from the radiator as the engine was cranked. This result confirms that one or both of the head gaskets are blown.
CASE 2: The coolant DID NOT bubble out NOR shoot out from the radiator as the engine was cranked. This is the correct test result.
If the engine doesn't start, in your 3.3L V6 Buick (Oldsmobile), go to: TEST 3: Cylinder Compression Test.
If the engine, in your 3.3L V6 Buick (Oldsmobile), runs but overheats, go to: TEST 4: Using A Chemical Block Tester (Combustion Leak Tester).
TEST 3: Cylinder Compression Test
There are times that one of the head gaskets will burn between two side by side cylinders (the photo at the beginning of this tutorial shows this type of failure).
When this happens, those two side-by-side cylinders will have 0 compression and will misfire.
In most cases, the engine will start and run but will run very rough since it's only working with four cylinders.
Usually, although the engine is running very rough (misfiring), the engine will not overheat.
The only way to find out if the head gasket has burned in a location between two side-by-side cylinders is to do a compression test.
That is what we'll do in this test section. These are the test steps:
- 1
Disconnect the ignition coil from its electrical connector. This is will disable the ignition system and is an important safety precaution.
- 2
Disconnect the fuel pump relay from its electrical connector.
- 3
Disconnect all spark plug wires (from their spark plugs).
- 4
Remove all of the spark plugs.
- 5
Thread in the compression tester by hand, on the first spark plug hole you're gonna' start with.
Do not use any tools to tighten the compression tester. Hand tightening the compression tester is more than enough to get the proper results. - 6
Have a helper crank the engine as you observe the compression tester.
- 7
When the gauge's needle stops climbing, have your assistant stop cranking the engine.
- 8
Write down the reading and what cylinder it belongs to on a piece of paper (you can use the illustration above to help you identify the cylinder).
- 9
Remove the compression tester and repeat the above steps in the remaining cylinders.
OK, let's take a look at what your results mean:
CASE 1: All cylinder compression readings where normal. This is the correct test result and it confirms that the head gaskets are OK (not burned at a spot between two side-by-side cylinders).
If you still suspect a blown head gasket, go to: TEST 4: Using A Chemical Block Tester (Combustion Leak Tester).
CASE 2: Two side by side cylinders had 0 PSI compression. This test result confirms that the head gasket is burned thru' at the point between those two cylinders. You will need to replace both head gaskets.
