TEST 2: Coolant Shooting Out From Open Radiator
This second test is an easy one too and simply requires that you remove the radiator cap and then crank the engine.
If the head gasket is blown, then the coolant will shoot out of the opened radiator.
If cranking the engine does not disturb the coolant (inside the radiator), then your next step is either check engine compression or do a block test with a block tester.
IMPORTANT: Do not remove the radiator cap if the engine is hot or has been running for any length of time. Let the engine cool down completely before you remove the radiator cap.
Let's get started.
- 1
Remove the radiator's cap. Check to see if there is coolant in the radiator. If the radiator is empty, add some water or coolant to bring it up to the radiator's neck level.
- 2
Crank the engine with the help of helper, 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 shot out from the radiator as you cranked the engine. This confirms that one or both of the head gaskets are blown.
CASE 2: The coolant DID NOT shoot out from the radiator. This is the correct and expected test result.
If your 3.3L V6 Nissan Frontier (Xterra or Pathfinder) DOES NOT start or runs with a misfire, go to: TEST 3: Engine Compression Test.
If your 3.3L V6 Nissan Frontier (Xterra or Pathfinder) does start but overheats within minutes, go to: TEST 4: Using A Chemical Block Tester (Combustion Leak Tester).
TEST 3: Engine Compression Test
If the engine does not start in your Nissan Frontier (Xterra or Pathfinder), then the next step is to do an engine compression test. If the engine starts and runs, then you skip this section and go to TEST 4.
The purpose of the compression test is to find out if one of the two head gaskets has burned in a spot between two cylinders.
If one of the head gaskets has burned in a spot between two cylinders then you're gonna' have two dead cylinders.
You can see an example of this type of head gasket failure in the image at the very beginning of this tutorial.
These are the test steps:
- 1
Remove all six spark plugs.
Disable the ignition system by disconnecting the distributor from its engine wiring harness connector. - 2
Thread in the compression tester by hand in the spark plug hole of cylinder #1.
Do not use any tools to tighten the compression tester. Hand tightening the compression tester is more than enough to get the proper results. - 3
Have your helper crank the engine. The needle on the tester will climb, as the engine cranks, till the cylinder reaches its maximum compression. Once it stops climbing, have your helper stop cranking the engine.
On a piece of paper, write down the reading and what cylinder it belongs to (you can use the illustration above to help you identify the cylinder). Repeat the above steps in the remaining cylinders.
Let's take a look at what your test results mean:
CASE 1: All cylinder compression readings were above 0 PSI. This is the correct and expected test result.
CASE 2: Two side by side cylinders had 0 PSI compression. This engine compression test result confirms that the head gasket (of that bank of cylinders) is burned thru' at the point between those two cylinders. You'll need to replace the head gasket.
