TEST 2: Coolant Shooting Out Of Radiator
The second test I would do, after checking the condition of the engine oil sticking to the oil dipstick, was to see if cylinder compression pressures were leaking into the cooling system.
This test simply involves removing the radiator cap and cranking the engine. If the head gasket is blown, coolant will be shot out of the radiator as the compression pressures try to escape via the cooling system (instead of being contained within the cylinder).
In the majority of the cases, when a head gasket burns to the point that compression is leaking into the cooling system, the engine doesn't start anymore.
OK, these are the test steps:
- 1
Remove the radiator cap from the radiator. If the coolant level is low, top it off before proceeding.
IMPORTANT: The engine should be completely cold before you open the radiator cap. Opening the radiator cap on a hot engine can spray hot coolant all over you and severely burn you. - 2
Stand at a safe distance from the engine but within view of the radiator.
- 3
When ready, have your helper crank the engine.
You'll see one of two results: The coolant shoots out violently when the engine was cranked -OR- the coolant was not disturbed at all.
Let's take a look at what your test results mean:
CASE 1: The coolant shot out of the radiator. This confirms beyond a shadow of a doubt that you do have a blown head gasket on your hands.
CASE 2: The coolant DID NOT shoot out of the radiator. So far so good. In TEST 1, you confirmed that coolant isn't mixing with the engine oil. In this test you have confirmed that no exhaust gases are escaping thru' the radiator...
If you still think that you do have a blown head gasket on your Toyota, read the next test. Go to TEST 3
TEST 3: Engine Compression Test
If you're 2.2L Toyota Camry starts and runs, you can skip this test and go to: TEST 4: Using A Chemical Block Tester (Combustion Leak Tester).
In a few instances, over the past few years, I have diagnosed vehicles with a blown head gasket that burned at the point between two cylinders. This caused the compression of one cylinder to escape into the other and vice-versa.
The end result of this condition was an engine that would crank but not start. I was able to verify this by doing a compression test and it's the 3rd test I'm gonna' recommend you do:
- 1
Disable the fuel system and the ignition system.
- 2
Remove the spark plugs and install the compression tester (hand tight only) on the first cylinder you're gonna' test.
- 3
Have a helper crank the engine while you observe the compression tester. When the needle stops moving, have your helper stop cranking the engine.
- 4
Write down the compression readings. Repeat on the next 3 cylinders.
Let's take a look at what your test results mean:
CASE 1: You got 2 side by side (adjacent) cylinders with 0 PSI. This confirms beyond a shadow of a doubt that you do have a blown head gasket on your hands.
CASE 2: All cylinders had sufficient compression. This is the correct and expected test result.
If you still suspect that your vehicle has a blown head gasket, go to: TEST 4: Using A Chemical Block Tester (Combustion Leak Tester).
