Category Archives: STi

2.5RS, AWD, Drivetrain, exhaust, forester, gc8, Impreza, Legacy, STi, Subaru, Suspension, Transmission, Turbo, UK, USDM, WRX

Maintenance Inspections for Subaru:

Maintenance Inspections for Subaru:

Subaru vehicles are more reliable than ever before. To assure their continued reliability, a schedule of inspection and maintenance (I & M) services is prescribed by Subaru of America for every Subaru vehicle sold. A copy of this schedule can be found in the Warranty and Maintenance Booklet located in the vehicle glove compartment.

Maintenance Inspections for Subaru:
Subaru vehicles are more reliable than ever before. To assure their continued reliability, a schedule of inspection and maintenance (I & M) services is prescribed by Subaru of America for every Subaru vehicle sold.

Subaru vehicle maintenance inspections services are divided into recommended intervals beginning with three months or 3000 miles (whichever comes first). Each additional level in the maintenance schedule (7,500/15,000/ 30,000 miles) adds more maintenance and inspection steps to the process. The 15,000 (15 month) and 30,000 mile (30 month) services are ‘major’ services, and include the most comprehensive range of component checks, part replacements and adjustments.

If you are already familiar with Subaru vehicles, you may have developed a routine when performing a vehicle safety maintenance inspections. Following a set routine allows you to start at one end of the vehicle and end up at the other end, having performed all of the necessary safety inspection steps along the way.

Repetition of the safety inspection may also allow you to commit the steps to memory, but a checklist can be a helpful addition that leaves nothing to chance (or memory). Checking items off the checklist provides a written record that can be shared with the customer and retained for your service records as well.

Recommended steps in a Subaru Safety Maintenance Inspections  are also spelled out in the owner’s Warranty and Maintenance Booklet. Some of the steps overlap services performed during the scheduled maintenance program. It could be argued that any scheduled maintenance should always include a Safety Inspection. Most of the Safety Maintenance Inspection steps are based on common sense, but it’s surprising how frequently these simple suggestions are ignored.

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2.5RS, AWD, forester, gc8, Impreza, Legacy, STi, Subaru, Suspension, USDM, WRX

Wheel Alignment For Subarus:

Wheel Alignment For Subaru:

Wheel arch height (vehicle ride height) as well as front and rear wheel alignment should be inspected at 30 month/30,000 mile intervals. Winter driving and its attendant chuckholes may shorten that maintenance interval for some drivers

While inspecting wheel alignment, also check for obvious signs of damage to suspension components, tightness of bolts and nuts and the condition of other under car components.

Check, adjust and/or measure wheel alignment in accordance with the following procedures:

1.) Wheel arch height (front and rear)
2.) Camber (front and rear)
3.) Caster (front)
4.) Front toe-in
5.) Rear toe-in
6.) Thrust angle (rear)
7.) Wheel steering angle

1. Wheel Arch Height

1.) Adjust the tire pressures to specifications.
2.) Set the vehicle under “curb weight” conditions (empty luggage compartment, install spare tire, jack, service tools, and top off fuel tank).
3.) Set steering wheel in a wheel-forward position.
4.) Suspend a thread from the wheel arch (point “A” in figure above) to determine a point directly above the center of the spindle.

Subaru Wheel Alignment: Measure the distance between the measuring point and the center of the spindle.

5.) Measure the distance between the measuring point and the center of the spindle.
6.) Consult the service manual for Wheel Arch Height specifications.

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2.5RS, Drivetrain, EJ25, EJ257, forester, gc8, Impreza, STi, Subaru, USDM, WRX

Valve Adjustment DOHC Engine Part 2

Valve Adjustment Tool and
Adjustment Procedures:

As we mentioned, it takes a special tool to work within the limited clearance area between the cylinder heads and the frame rails. The ST 498187 is a three part tool. One part wraps around the cam lobes, a second touches the outer edges of two shim buckets, and a third eccentric bolt exerts the necessary pressure to push a pair of shim buckets away from the cam lobe to make shim removal and replacement possible.

The tool installed in the three steps:

• Wrap the first half of the tool (part A) around the lobes.
• Attach the second half (part B) to part A by sliding its pins through the slotted holes in part A.
• Install the eccentric bolt (part C) into the hole in part A.

Valve Adjustment Tool and Adjustment Procedures: As we mentioned, it takes a special tool to work within the limited clearance area between the cylinder heads and the frame rails.

The eccentric bolt forces parts A and B away from one another. Because part A can’t move (it’s wedged against the cam lobes), the only thing that can move is part B. Part B moves by forcing the shim buckets downward, away from the camshaft.

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2.5RS, Drivetrain, EJ25, EJ257, forester, gc8, STi, Subaru, USDM, WRX

Valve Adjustment DOHC Engine

Valve Adjustment DOHC 2.5 Liter Engine:

The first versions of the 2.5 liter twin cam engines employed non-hydraulic valve actuation. Like the timing belt, the clearance between the engine valves and the shim and bucket valve actuators does not require inspection and/or adjustment until 105,000 miles have elapsed. However, various circumstances may require an adjustment before that milestone is reached.

Valve Adjustment: Unlike some overhead cam engines that require you to rotate the cam until each cam lobe is facing 180 degrees away from the adjustment shim, Subaru has very specific procedures for adjusting four valves at a time (a pair of intakes and a pair of exhausts).

Clearance is tight and there is little room to work between the cylinder heads and the left and right frame rails. A special tool (ST 49818700) is available for depressing the valves and removing the adjusting shims. Without this tool, the job is impossible to accomplish with the engine in the car. Once again, we had the benefit of working on an engine that had already been removed from the car. Before you can adjust the valves, the engine must be cold. Consult the service manual to determine the parts that will need to be moved or removed to make some room to work.

Unlike some overhead cam engines that require you to rotate the cam until each cam lobe is facing 180 degrees away from the adjustment shim, Subaru has very specific procedures for adjusting four valves at a time (a pair of intakes and a pair of exhausts). The pairs of intakes and exhausts are never for the same cylinder, which makes things rather interesting. This system requires you to turn the crankshaft a total of four times to complete the adjustment procedure.

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AWD, Impreza, JDM, STi, Subaru, USDM, WRX

Limited Spoiler 07 STi install:

Limited Spoiler 07 STi install:

This is a step by step guide in installing the Limited Spoiler from a 07 STi.

Here is the limited spoiler, already painted to match the lid:

The part number is actually E7210FE900 and the kit cost $221 shipped at the time of purchase, but prices may have changed.

Limited Spoiler 07 STi install: Here is the spoiler already painted and ready to install.

1.)From the factory this fitting is already installed in the center of the spoiler, if you bought it unpainted, remove this BEFORE you get your spoiler painted. It just makes it easier. I simply cut the nipple off so that nothing is protruding from the bottom of the spoiler. You can also use the nipple and cut a hole in your trunk.

Limited Spoiler 07 STi install: If you bought it unpainted, remove this BEFORE you get your spoiler painted.

2.) The 3M tape you want to use looks like this, I picked it up at the local auto parts/auto body shop. You can see the part number in the picture. It costs around $15 and you will have enough for two or more installations.

The 3M tape you want to use looks like this, I picked it up at the local auto parts/auto body shop. You can see the part number in the picture.

You can buy the 3M Tape here:


3M(TM) Automotive Acrylic Plus Attachment Tape 06384, Black, 1/2 In X 5 Yds, 45 mil [PRICE is per ROLL]

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AWD, Drivetrain, EJ257, Impreza, STi, Subaru, Suspension, Turbo, USDM, WRX

Steering Rack Bushings Install on a 08+ STi

Steering Rack Bushings Install on a 08+ STi

This is a step by step guide on installing steering rack bushings (whiteline) on a 08+ WRX/STi. This needs to be done the right way and all the bolts NEED to be torqued with a torque wrench to factory spec for the car to be in a safe operating state.

1.) Remove the under tray. There are 2 12mm bolts towards the front, 1 12mm bolt on the rear, 2 clips on the rear. and 2 plastic pop-out clips on the sides near each wheel well.

2.) After removing the under tray you will need to remove 10 14mm bolts holding the cross member support brace (otherwise known as the jack plate) in place. The bolts that are to be removed are circled in red and yellow.

Note: The bolts circled in yellow are secured by nuts on the topside so you will need the 14mm wench as well. These bolts are torqued down pretty tight if they have never been removed before.

Steering Rack Bushings Install on a 08+ STi: The bolts circled in yellow are secured by nuts on the topside so you will need the 14mm wench as well.

3.) Once the cross member support is removed the steering rack will be exposed as pictured below. Note the location of the 3 bushings denoted by the red arrows.

Steering Rack Bushings Install on a 08+ STi: Note the location of the 3 bushings denoted by the red arrows.
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Ej20, ej20G, EJ257, gc8, Intake, Intercooler, STi, Subaru, TMIC, Tuning, Turbo, WRX

Overboost and Underboost Subaru common causes:

Overboost and Underboost Subaru common causes:

The common causes for overboost or underboost: This is a basic guide on the possible causes and some solutions to those causes of a overboost or a underboost situation in a turbocharged subaru.

Overboost and Underboost Subaru common causes: Turbo Subarus: Common Overboost and Underboost issues with Turbo Subarus.

Overboost:

1.) Decat + High flow induction –  Cure: Reduction of the solenoid duty cycle or alteration of restrictor size will help return boost output to its normal level.

2.) Split, poor fitting, or disconnected pipes – Cure: Replace or refit pipes, the pipes that will cause this issue are between the wastegate actuator, solenoid, and the turbo. Including up to the restrictor on the return pipe of the 3 port solenoid.

3.) Manual Boost Controller – Electronic Boost Controller set too high – Cure: Don’t be so greedy and back the boost duty/adjuster off to a safe level.

4.) Restrictor Pill not fitted / size incorrect – Cure:  Ensure restrictor pill is fitted (3 port) if so on a 3 port reduce the restrictor size and on the 2 port increase the restrictor size to reduce the boost to a safe level.

5.) Clogged 3-port solenoid: It is possible that the flow of air through the 3-port solenoid could be restricted between the turbo outlet port and the wastegate actuator port if the solenoid is very dirty (usually oil vapor from the intake system), this allows the wastegate to remain clamped shut longer than it should be causing a potential overboost situation. Cure: Clean with carb or clutch/brake cleaner.

6.)Loss of solenoid funcation: Although this is not bverboost it shows itself with very simmilar symptoms, its an interesting scenario. It is possible for the solenoid to fail or even stick shut while under boost. This will result in a rapid reduction of boost pressure to wastegate pressure approx 0.5 BAR. So if you were running at full boost 1.0 BAR for example and the solenoid was to fail shut it would feel just like overboost as the wastegate rapidly opens due to the solenoid blocking off the spill from the wastegate. Cure: Either clean the solenoid with carb or clutch+brake cleaner or replace the solenoid.

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2.5RS, AWD, Drivetrain, Ej20, forester, gc8, Impreza, JDM, Old School Subaru, STi, Subaru, UK, USDM, WRX

ABS 5.3 Antilock Brake System for Early Subaru Part 5:

ABS 5.3 Antilock Brake System for Early Subaru Part 5:

 

ABS 5.3 Antilock Brake System for Early Subaru Part 5:
Beginning in approximately December of 1996, a new antilock braking system called ABS 5.3 was installed on Legacy vehicles equipped with ABS.

 

Beginning in approximately December of 1996, a new antilock braking system called ABS 5.3 was installed on Legacy vehicles equipped with ABS. This system uses a Bosch hydraulic control unit and a Nippon electronic control unit. ABS 5.3 is a four channel control design which can independently control the front wheels and utilize select low control to control the rear wheels (a system which provides the same fluid pressure control for the two rear wheels if either wheel starts to lock up).

Although similar to other Subaru ABS systems, there have been enhancements to component operation and location. Diagnosis has also improved because of the ability of the 5.3 ABS system to communicate with the Select Monitor. The hydraulic control unit or HCU is located under the hood on the right side of the engine compartment. The size of the HCU has decreased by approximately a third from that of the ABS-2E system, used on previous model year vehicles.

The HCU controls brake fluid flow by utilizing eight solenoid valves. There is an inlet solenoid valve and an outlet solenoid valve for each wheel. Mechanically, the inlet solenoid valve is open during normal braking, and the outlet solenoid valve is closed. The HCU also contains a motor and pump assembly, which operates only while ABS is actively controlling the brake fluid flow–preventing a wheel lock.

ABS 5.3: Beginning in approximately December of 1996, a new antilock braking system called ABS 5.3 was installed on Legacy vehicles equipped with ABS.

Externally the HCU of the ABS 5.3 has a relay box attached. This allows troubleshooting of the valve and motor relay area to be kept separate from the troubleshooting of the solenoid valves and pump motor. There are four modes of operation for the ABS 5.3 system. They are normal, pressure-drop, pressure-hold and pressure-increase. When wheel lockup is sensed, Mode Two, Mode Three and Mode Four may be activated. They are described as follows:

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