Subaru Head Gasket Repair

Typically a Subaru head gasket leak often means that there is an internal or external leak within the Subaru Engine. In recent times we have seen an increase in external Subaru head Gasket failures on the 2.5 Subaru non turbo engines.

Normally External water seepage on the 2.5 Subaru Engine normally goes undetected for some time as it is only in the advanced stages that water loss causes overheating. Sensitive customer may report unusual smells “coolant residue burning on exhaust and other very hot components however most customers will be unaware of such a problem.

Most 2.5 Subaru head Gasket related issues if not fixed can cause Subaru engine problems, these include:

Rusting of the Cast iron Bore,
Subaru Engine failure
Engine seizure.

Subaru Head gasket repair is very successful when fixed correctly additives such as cooling system conditioners, Bars stop leak, wwp-99, Wynns stop leak should never be considered to fix leaking Subaru head gaskets as expensive repairs to your Subaru cooling system will result.

2.5 Subaru effected models include:

1997 – Current Subaru Outback Head Gasket
1999 – 2010 Subaru Liberty Head Gaskets
2003 – Current Subaru Forester Head Gasket
2003 – 2005 Subaru Impreza Head Gasket

Our Subaru Service Centre Sydney can fix all Subaru problems.

All questions can be answered by our specialised Subaru mechanics

Robert Mastroianni
Administrator
45

Rob has 27 years’ experience as a motor mechanic, and is an automotive transmission specialist. Rob was an automotive teacher at Tafe NSW, teaching Automatic transmissions and is very good at communicating technical ideas to lay people. Rob mans the phones at ADS and is the bright cheerful voice you first encounter when you call us. There isn’t much Rob doesn’t know about transmissions.
Niazi Helou
Director
37

Cars are in Niazi’s blood and from the age of five his only ambition was to become a mechanic. Niazi studied at the University of Sydney and later at Sydney Tafe, where he completed an Engineering Diploma. He has extensive knowledge of all Subaru makes and re-manufacturing processes. He specialises in business management and the reconditioning of Subaru Engines and Transmissions.
Nick Mashkivskyy
Senior Mechanic
41

Nick joined All Drive Subaroo after leaving Subaru where he held the position of head mechanic. With over 16 years’ experience in the motor trade, he brings extensive knowledge of Subaru faults and repairs. He is currently the head mechanic at All Drive Subaroo and he uses his knowledge to bring you the best possible service.
Gary Nobrega
Quality Control
30

Gary is a fully qualified mechanic with 14 years’ experience in the motor trade, and a total of 5 years specialising in Subaru vehicles. Gary has a great eye for detail and (like everyone on the ADS team) is a perfectionist, which is why he is our Quality Control and Delivery specialist. Gary’s goal is to make sure all repairs and servicing on your car are completed to the highest possible standard.
Gabriel Perugini
Apprentice
17

Gabriel is near the end of his apprenticeship with All Drive Subaroo and will soon be a fully qualified mechanic. In his time with us he has gained extensive knowledge of Subaru vehicles and is looking forward to gaining more knowledge in the diagnostics area of Subaru servicing.
Vanessa Macintosh
Factory Assistant
24

Vanessa’s goals are to achieve the best results when working with ADS Subaru specialist engine and transmission builders. Vanessa is a hard worker, cheerful, helpful at all times. When not helping us produce top quality engines and gearboxes, she jumps out of aeroplanes for fun! Vanessa’s motto is “Stay strong”.
Jorge Mora
Mechanical Engineer
25

Jorge has a degree in Mechanical Engineering. He has been working at All Drive Subaroo for the last three years in Research and Development. Jorge also handles the tedious and stressful inventory of parts and stock organization, and oversees parts that are installed on vehicles.
Vee
Usher
7

Vee is our beloved Usher and Traffic Controller at ADS, so when you see Vee give him a pat and say Hi 😉

Select	Type 1 EJ20 Standard Stroke Cosworth Street tuff Engine includes; New Subaru EJ20 STI Engine case New Subaru EJ20 STI Forged Crankshaft New STi Forged Connecting Rods Cosworth Forged Pistons and rings Cosworth Coated, Tri-metal bearings Cosworth Head Gaskets New Subaru Oil pump New Subaru Engine Oil pick up New Subaru Engine Oil Sump Balanced to within .5 gram
Select	Type 2 EJ25 Standard Stroke Cosworth Street tuff Engine includes; New Subaru EJ25 STI Engine case New Subaru EJ25 STI Forged Crankshaft New STi Forged Connecting Rods Cosworth Forged Pistons and rings Cosworth Coated, Tri-metal bearings Cosworth Head Gaskets New Subaru Oil pump New Subaru Engine Oil pick up New Subaru Engine Oil Sump Balanced to within .5 gram
Select	Type 3 EJ20 2.1L Stroker Cosworth Engines includes; New Subaru EJ20 STI Engine case New Subaru STI Forged Crankshaft New Forged Connecting Rods Cosworth Forged Pistons and rings Cosworth Coated, Tri-metal bearings New Subaru Oil pump New Subaru Engine Oil pick up New Subaru Engine Oil Sump Balanced to within .5 gram
Select	Type 4 EJ25 2.6L Stroker Cosworth Engines includes; New Subaru EJ25 STI Engine case Cosworth 81mm Billet Crankshaft Cosworth Forged Connecting Rods Cosworth Forged Pistons and rings Cosworth Coated, Tri-metal bearings Cosworth Head Gaskets Cosworth Head Stud Kit Cosworth Stainless Valves Cosworth High Rev valve Springs Cosworth Valve Retainers Cosworth Valve Locks Cosworth Oil pump New Subaru Engine Oil pick up New Subaru Engine Oil Sump Balanced to within .5 gram

Add	Kevlar Timing Belt Cosworth Kevlar High Performance Timing belts are 300% stronger than original equipment timing belts
Add	Billet Timing Belt Guide The Cosworth Billet timing belt guide replaces the original sheet metal timing belt guide that can flex from belt deflection when subjected to extreme rpms causing the timing belt to skip one or more teeth on the crankshaft sprocket.
Add	Head Stud Kit Essential for high performance engine builds, heavy duty head studs reduce cylinder head movement in high boost or high compression engines optimising cylinder head to block sealing. Cosworth Ultra High Performance Head Studs are manufactured from H11 tool steel with 240,000+psi tensile strength and come complete with nuts and washers. They are manufactured with hex broach ends for ease of installation
Add	Oil Control Baffle The Cosworth Subaru Oil Pan Baffle has been engineered with diverters to control oil returning from the cylinder heads to the pan directing it away from the crankshaft. Additionally, one-way valves prevent oil from reentering the upper crankcase chamber thereby limiting blow by and preventing oil starvation during hard driving.
Add	Engine Oil Pump High performance engines dissipate a substantial amount of heat through the oil system. Maintaining oil pressure and control along with an increase in actual volume will help assist this process and stabilize oil temperatures. Cosworth Engine oil pumps are high flowed and pressure blueprinted.
Add	Billet Crankshaft 75mm (EJ20) Increased engine performance often means increased engine speed and load. Original factory crankshafts may not be able to withstand the added stress, resulting in catastrophic engine failure. Additionally, many OE crankshafts rod journals are lubricated from only one main oil feed. Cosworth billet crankshafts featurefull-flowoiling whereby each rod journal is lubricated from two main sources. This provides superior lubrication during sustained high rpm use preventing rod bearing failure. Cosworth Subaru crankshafts are manufactured entirely from high grade steel in a light-weight, high strength design with a uniqueIsotropic Super Finish (ISF®).
Add	Billet Crankshaft 79mm (EJ25) Increased engine performance often means increased engine speed and load. Original factory crankshafts may not be able to withstand the added stress, resulting in catastrophic engine failure. Additionally, many OE crankshafts’ rod journals are lubricated from only one main oil feed. Cosworth billet crankshafts are full-flowing whereby each rod journal is lubricated from two main sources. This provides superior lubrication during sustained high rpm use preventing rod bearing failure. Cosworth Subaru crankshafts are manufactured entirely from high grade steel in a light-weight, high strength design with a unique Isotropic Super Finish (ISF®).
Add	Billet Crankshaft 81mm (EJ25 Stroker) Increased engine performance often means increased engine speed and load. Original factory crankshafts may not be able to withstand the added stress, resulting in catastrophic engine failure. Additionally, many OE crankshafts rod journals are lubricated from only one main oil feed. Cosworth billet crankshafts are full-flowing whereby each rod journal is lubricated from two main sources. This provides superior lubrication during sustained high rpm use preventing rod bearing failure. Cosworth Subaru crankshafts are manufactured entirely from high grade steel in a light-weight, high strength design with a unique Isotropic Super Finish (ISF®).
Add	Forged Connecting Rods To ensure engine reliability in all conditions, original connecting rods should be replaced with heavy duty specification parts. Cosworth Forged Connecting Rods are manufactured from high strength 4340 (EN24) steel and machined to exacting tolerances.
Add	Big port Cylinder Heads with Camshafts (2.5lt Only) Each original cylinder head design has been carefully evaluated and tested to establish what improvements are required to meet target performance levels. Hours of testing and flow bench validation are used to determine the best advanced port design yielding maximum usable power and response. However, there is more to cylinder head design than just maximum flow. It is critical that port velocity is maintained to ensure drivability, and that valve train components are matched to guarantee reliable performance. Once all of these factors have been tested and validated, the final port contour is digitized. Using the digitized program, we then reshape both intake and exhaust ports using a 5 axis CNC mill producing an accurate and consistent port shape every time. In addition to re-shaping and enlarging the intake and exhaust ports, most Big Valve Cylinder heads feature a re-shaped combustion chamber to un-shroud the valves, increasing air flow and performance. After machining, each cylinder head receives a multi-angle high performance valve job on our precision Newen® CNC valve seat cutter. Then each cylinder head is ultrasonically cleaned, serialized and finally hand assembled with select high performance valve train components, ready to install on your engine.
Add	Hi Lift Camshafts (EJ20) Cosworth camshaft designs are the most efficient in providing maximum usable power across the widest power band. Each cam is ground from a new blank and finished using the same procedures we use in our extreme level race engines. Cosworth camshafts are profiled to increase boost response thereby increasing engine torque and power.
Add	Hi Lift Camshafts (EJ25) Each cam is ground from a new blank and finished using the same procedures we use in our extreme level race engines. Cosworth camshafts are profiled to increase boost response thereby increasing engine torque and power.
Add	High Rev Dual Valve Springs (EJ25) Cosworth Ultra Race Valve Spring Kits are engineered for use in situations that require valve control in extreme conditions. Each kit consists of dual valve springs with matched lightweight titanium retainers, keepers, and hardened steel spring seats. Cosworth Ultra Race Valve Springs are wound from the highest quality chrome silicone steel with chamfered ends and are heat treated and stress relieved for long term reliability. Ultra Race Valve Spring kits are compatible with Cosworth high performance valves.
Add	High Rev Valve Spring (EJ20) Cosworth High RPM Valve Springs are the result of countless hours of engineering, testing and validation ensuring the best possible spring for high performance applications. Cosworth High RPM Valve Springs are wound from the world's finest Japanese Kobe steel and feature dual chamfered ends to reduce wear on seats and retainers. Each spring has been engineered with increased seat pressure along with higher lift capability for optimum performance potential and improved valve control. Single spring design allows easy installation with no machining required and is perfect for typical high performance use.
Add	Intake and Exhaust Valves Large diameter valves are essential for improved air flow. Cosworth high performance intake valves are produced from high quality stainless steel for maximum durability. Exhaust valves are machined from Inconel for high temperature (2400° F) reliability. Each valve features a swirl polished back for improved air flow and dished face for additional weight reduction. Some Cosworth High Performance Valves are only compatible with Cosworth Ultra Race Valve Spring Kits.
Add	Intake Manifold The Cosworth Subaru High Volume Inlet Manifold is cast from aluminium featuring large tapered runners with radiused inlets for improved air flow. Plenum volume has been substantially increased and tuned for power. Engineered for easy installation, this manifold is the key to making big power. The Cosworth EJ257 plenum is designed for use with the 2004-2009 STI engines equipped with electronic throttle control. The plenum is not designed for use with any cable-actuated throttle body EJ20/25 applications. This plenum is designed to replace the factory Subaru plenum in vehicles equipped with an aftermarket front-mounted intercooler (FMIC) kit. Throttle body position remains stock, ensuring fitment with any brand FMIC kit designed for the stock throttle body and intake manifold.
Add	Thermal Intake Manifold Gaskets The Cosworth Thermal Guard Composite Intake Gasket is designed to reduce inlet air temperature by isolating the intake manifold from the heat generated by the engine's cylinder head. Reducing the temperature of the inlet manifold also reduces the temperature of the intake air charge. The density of cooler air is greater than that of warm air. A denser intake air charge contains more oxygen thereby producing in increased power and torque.
Add	Dry Sump Kit The Cosworth Dry Sump Setup Kit for the Subaru EJ series engine is a must for race and performance applications. Dry sump oiling systems offer an unparalleled level of safety and reliability compared to factory Wet Sump systems. Complete crankcase oil scavenging reduces excessive and residual oil that can cause blow-by and power loss. A dry sump also offers more consistent oil pressure to the engine, improved scavenging, and increased ring seal due to greater pan vacuum. The Cosworth Dry Sump System for the Subaru EJ20/EJ25 replaces the original oil sump with a machined from solid, low profile alloy pan with twin scavenge ports, internal baffling and o-ring sealing. A two stage scavenge pump driven by a HTD belt, mounted to a heavy duty bracket evacuates the oil from the engine.

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Cosworth Engine Upgrade Quote

Select Engine Type

Type 1 EJ20 Standard Stroke Cosworth Street tuff Engine includes;

Type 2 EJ25 Standard Stroke Cosworth Street tuff Engine includes;

Type 3 EJ20 2.1L Stroker Cosworth Engines includes;

Type 4 EJ25 2.6L Stroker Cosworth Engines includes;

Performance Addon Parts

Kevlar Timing Belt

Billet Timing Belt Guide

Head Stud Kit

Oil Control Baffle

Engine Oil Pump

Billet Crankshaft 75mm (EJ20)

Billet Crankshaft 79mm (EJ25)

Billet Crankshaft 81mm (EJ25 Stroker)

Forged Connecting Rods

Big port Cylinder Heads with Camshafts (2.5lt Only)

Hi Lift Camshafts (EJ20)

Hi Lift Camshafts (EJ25)

High Rev Dual Valve Springs (EJ25)

High Rev Valve Spring (EJ20)

Intake and Exhaust Valves

Intake Manifold

Thermal Intake Manifold Gaskets

Dry Sump Kit

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Subaru Head Gasket Repair

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