A blown head gasket causes three unique symptoms that you can check for very easily. So if you need to see/know if your Isuzu has a blown head gasket or not -this article will show you how to check for them with three easy tests. I've also included info on the block test done with a combustion leak detector.
Contents of this tutorial:
You can find this tutorial in Spanish here: Cómo Probar El Empaque De Cabeza (1993-1996 2.6L Isuzu) (at: autotecnico-online.com).
Important Tips And Suggestions
TIP 1: Never open a radiator cap if the engine is hot or has been running for an extended period of time or you run the risk of getting scalded by the hot coolant.
TIP 2: Never remove the spark plugs from a hot engine or you run the risk of stripping the spark plug hole threads in the cylinder head.
Symptoms Of A Blown Head Gasket
The number one cause of a blown head gasket is engine overheating and when the head gasket burns, you'll most always see one or all of these symptoms:
- Engine oil mixed with coolant, which turns the oil a color like coffee with too much cream.
- And/or compression and exhaust gases escaping thru' the cooling system. This causes coolant to shoot out from the radiator, if you crank the engine with the radiator cap off.
- The head gasket burns between two cylinders. This will result in a no start condition.
- Engine overheats.
- White smoke coming out of the tail-pipe and that smells like anti-freeze being cooked.
In this article, we'll explore how to test the first three (of the above list), since they're the most common end result of a blown head gasket.
HEAD GASKET TEST 1: Checking Engine Oil Color
When the head gasket gets blown, the most common result is coolant mixing the engine oil.
So the first test is to check the color of the engine oil.
This is what you need to do:
Open your Isuzu's engine hood.
Pull the engine oil dipstick out of the engine.
You'll see one of two things:
1.) The color of the oil is the color of ‘coffee with too much creamer’.
2.) The color of the oil is its normal color.
Let's find out what the color of the oil means:
CASE 1: The color of the oil is a light tan, like coffee with too much creamer. This is really bad news and confirms that the head gasket is blown on your vehicle, no further testing is required.
If you're wondering why does the oil look like this? There are 3 main reasons:
- The engine overheated and caused the cylinder head to warp and the head gasket to burn.
- This in turn causes the head gasket to stop sealing the oil and coolant ports in both the engine block and the cylinder head.
- This leads to the coolant entering the engine oil pan and mixing with the oil. As both of these mix, the resulting oil gets thick and turns to an off-white color.
CASE 2: The color of the oil is its normal color. So far so good, but you're not out of the woods yet. The next step is to check that exhaust gas and/or combustion pressure is not escaping thru' the radiator, go to: TEST 2: Coolant Shooting Out Of Radiator.