The Best Tips to Diagnose Your Subaru’s Faulty Head Gasket

Blown head gasket! No car owner wants to hear these three words! It’s an expensive repair. In the worst-case scenario, you may have to replace the engine of your Subaru. But wait! No need to get alarmed already. When head gasket issues are detected and addressed in their early stages, the situation may not be so dire. In this article, we will draw your attention to some common signs that may tell you there might be a faulty head gasket.

What is a head Gasket?

The head gasket is a seal that is located between the engine block and the cylinder head. Its job is to create a tight seal to prevent the engine fluid from leaking, and avert loss of pressure in the combustion chamber. A failed head gasket can result in oil and coolant leaks which, if not treated promptly, can lead to catastrophic engine failure.

How to Diagnose a Faulty Head Gasket?

The best way to actually diagnose whether your Subaru’s head gasket is having problems is to take it to a reputable garage. The reason for this is there are certain tests that a mechanic will perform, which will require specialized tools, equipment, and knowledge. It is also a matter of safety, as some of these tests need to be done when the engine is warm, you’ll need to test pressures, and you have to deal with corrosive fluids and toxic gasses.

Here are some tests to diagnose a blown head gasket:

• Compression Test: A professional mechanic will use specialized tools to check the compression in each cylinder. If the compression is measured as 0 PSI (pounds per square inch), then the gasket could be blown.
• Combustion Gas Test / Block Test: Another way of determining whether there might be a gasket leak is to test if there are any hydrocarbons present in the coolant. This means the combustion gasses are leaking into the coolant. This test involves certain specific steps while the engine is warm and some specialized equipment.
• Coolant System Pressure Test: When a pressure test is done on a coolant system and a mechanic sees air bubbles in the coolant inside the radiator, that’s positive evidence that the head gasket is blown.

Signs That Allow YOU to Detect a Blown Head Gasket

Below are some signs that your Subaru may have a malfunctioning head gasket. These are easy to notice and don’t require sophisticated equipment.

• Weeping Oil or Coolant: On a visual inspection if you notice there is oil or coolant present near the gasket area, that’s when you should be concerned and bring your Subaru in for a check. Oil or coolant weeping means you’ll see residue or build-up on the engine block or cylinder head. It may or may not be wet or moist, but it’s still a sign that the seal is broken.
• Engine Overheating: Do you notice your car habitually overheats? When the engine overheats, your Subaru’s MIL (Malfunction Indicator Lamp) on the dashboard turns on, warning you that the engine is overheating. The engine overheats because the coolant is unable to flow correctly due to a breach in the head gasket. This is a dangerous symptom. Please don’t delay contacting a professional mechanic.
• Engine Oil Check: As part of scheduled maintenance it is a good idea to check the engine oil regularly. During these inspections, remember to look for signs of contamination. If you observe a thick, milky-white substance in the oil, that could mean coolant is present in the oil, which only happens when there is a leak in the head gasket.
• Exhaust Gas Visual Check: If the exhaust gas coming out of your Subaru’s tailpipe looks like white smoke, then there’s a good chance the coolant is burning. This only happens if the head gasket is damaged or broken.

Keep In Mind

We cannot emphasize enough how crucial it is to get your Subaru checked out if you suspect there might be a malfunctioning head gasket. It’s true that a head gasket replacement is quite expensive, but remember, it’s not as expensive as having to change the entire engine! If coolant leaks into the engine, it will lead to irrevocable engine damage.

Franklin Automotive for Your Subaru

At Franklin Automotive, we have trained, ASE-certified (Automotive Service Excellence) mechanics who can help you with a blown gasket or any other problem. Please call us if you have any questions. You can stop by any of our locations in Alabama. We have locations in Hoover, Homewood, Vestavia, Mountain Brook, Pelham, Trussville, and Birmingham.