If you’re a Subaru owner, you know how reliable and long-lasting these cars can be. But even the most reliable cars need regular maintenance, and sometimes repairs are necessary. One common issue with Subarus is head gasket failure, which can cause a variety of engine problems. Rebuilding the head can save you money in the long run and extend the life of your engine. In this article, we’ll guide you through the process of rebuilding a Subaru head.
What is the Subaru head?
The head of a Subaru engine sits on top of the block and contains the valves, springs, and camshafts. The head gasket is sandwiched between the head and the block, sealing the combustion chambers and coolant passages. If the head gasket fails, it can lead to overheating, loss of power, and white smoke from the exhaust.
Why and when does it need to be rebuilt?
Rebuilding the head is usually necessary if the head gasket has failed, but it can also be done for preventative maintenance. Signs that a head gasket has failed include coolant loss, low compression, and oil contamination. It’s important to catch head gasket failure early to prevent further damage to the engine.
What are the tools needed to rebuild a Subaru head?
Before you start rebuilding the head, you’ll need to gather the necessary tools. Here’s a list of tools you’ll need for the job:
- Torque wrench
- Socket set
- Head gasket kit
- New head bolts
- Valve spring compressor
- Camshaft holder
- Timing belt kit
- Engine hoist (if removing the engine)
Step-by-step guide on how to rebuild a Subaru head
Remove the cylinder head from the engine block. If you’re not comfortable doing this step yourself, seek the help of a professional.
Clean and inspect the head for cracks, warping, and wear. If the head is damaged beyond repair, consider purchasing a new or rebuilt head.
Remove the valves and measure their heights. Replace any valves that are out of spec. Be sure to keep each valve and its corresponding spring and retainer together.
Replace the valve stem seals while the valves are out.
Install the new valve guides. This can be a tricky step and may require specialized tools, so seek the help of a professional if needed.
Reinstall the valves, springs, and retainers in the head using a valve spring compressor.
Install the new head gasket onto the engine block.
Place the cylinder head onto the engine block, being careful not to damage the new head gasket.
Install the new head bolts and torque them to the manufacturer’s specifications using a torque wrench.
Install the timing belt and any other accessories that were removed.
Refill the engine with coolant and oil.
Start the engine and check for any leaks or abnormal noises.
Common mistakes to avoid while rebuilding a Subaru head
Not following the torque specifications for the head bolts. This can result in a blown head gasket.
Reusing old head bolts. Always use new head bolts when rebuilding the head as they are designed to stretch during installation.
Not checking for wear and damage on the valves and guides. Replacing only the head gasket and not addressing these issues can lead to a repeat failure down the road.
Not using a valve spring compressor to reassemble the valves and springs. Trying to do this step without the right tool can result in damage to the head or the valves.
Tips and tricks for a successful rebuild
Work in a clean and organized area to minimize the risk of losing parts or damaging the head.
Label and organize all parts as you remove them to make reassembly easier.
Take your time and don’t rush the job. Rebuilding a Subaru head can be a time-consuming process, but it’s important to do it right the first time.
Consider replacing other components while the head is off, such as the water pump or timing belt.
How much does it cost to rebuild a Subaru head?
Prices can vary depending on where you live and the extent of the damage. DIY rebuilds can cost anywhere from $500 – $1000 for parts and machine shop costs. Professional rebuilds can cost upwards of $2000.
Can I rebuild the head myself?
Rebuilding a Subaru head can be a challenging job, but it’s possible for experienced DIYers to do it themselves. If you’re not comfortable working on your own car, seek the help of a professional.
How long does a Subaru head rebuild take?
A DIY rebuild can take anywhere from 10-20 hours depending on your experience level. Professional rebuilds can take a few days to complete.
In conclusion, rebuilding a Subaru head can save you money and extend the life of your engine. However, it’s important to do the job right the first time to prevent further damage. Follow our step-by-step guide and our tips and tricks for a successful rebuild. If you’re not comfortable doing the job yourself, seek the help of a professional.