Subaru Turbocharger Rebuild Service

Subaru
Turbo
Rebuild

Complete in-house rebuild service for every turbocharged Subaru. WRX TD04L, STI VF series, Legacy GT, Forester XT, and FA20DIT. AVCS banjo bolt screen inspection and report included on every EJ rebuild. In-house VSR balancing since 2008.

Start Your Rebuild AVCS Screen Info →
WRXTD04L / VF52 / VF57
STIVF39 / VF43 / VF48
JDMVF22 through VF60
WRX 2002-2007
TD04L Mitsubishi EJ205
STI All Years
VF IHI Series VF39-VF48
WRX 2008-2014
VF52 IHI EJ255
WRX 2015+
VF57 IHI FA20DIT
Legacy GT / Forester
VF40 VF41 VF45 VF54
AVCS Screens
Remove Subaru TSB recommends
Critical Maintenance Point

The AVCS
Screen Problem

The AVCS (Active Valve Control System) is Subaru's variable camshaft timing system on EJ205, EJ207, EJ255, and EJ257 engines. It uses oil pressure controlled by solenoid-operated Oil Control Valves (OCVs) to advance and retard cam timing. Good so far.

The issue is that Subaru installed small mesh screens inside the banjo bolts that supply oil to the AVCS system. These screens are meant to protect the AVCS solenoids from debris. In practice, they accumulate varnish deposits from degraded oil and eventually restrict or fully block oil flow -- not just to the AVCS, but to the turbocharger and cam journals that share the same oil supply passages.

There are multiple screens on the EJ engine. The locations vary by year and engine variant, but the most critical is the banjo bolt on the passenger side cylinder head that feeds both the turbo oil supply and the AVCS intake solenoid. When that one clogs, the turbo is starved simultaneously with the AVCS system. The first sign is often a P0011 or P0021 AVCS code before the turbo noise starts -- but the turbo was already running lean on oil by the time the code appeared.

Subaru acknowledged the problem directly. TSB 02-97-05 covers the AVCS screens. TSB 02-103-07 covers the separate turbo oil feed screen on the back of the passenger side head. Both TSBs recommend removal. The Subaru performance community -- NASIOC, IWSTI, Subaru Forester forums, every major Subaru specialist -- agrees without exception: remove the screens. The risk of clogging and oil starvation is far greater than any protection they provide on an engine with proper oil change intervals.

Because these screens are on the car and not on the turbo, we cannot inspect them during a rebuild. What we can tell you is what we found inside the CHRA. If the bearings and shaft show oil starvation patterns -- scoring, accelerated wear, coking deposits -- restricted oil flow is the most likely cause and the screens need to come out before anything we rebuilt goes back on the engine.

We recommend removing these screens entirely. Subaru issued TSBs directly addressing this problem -- TSB 02-97-05 for the AVCS screens and TSB 02-103-07 for the turbo oil feed screen -- and the recommendation in both is removal. The Subaru performance community agrees universally: the screens do not belong on any turbocharged EJ. The risk of them clogging and starving the turbo or cam journals is far greater than any protection they provide on a well-maintained engine with short oil change intervals. Because the screens are on the car and not on the turbo, we cannot inspect them during a rebuild. What we can do is tell you what we found at teardown -- if the CHRA shows signs of oil starvation, restricted oil flow is the likely root cause, and the screens need to come out before the rebuilt turbo goes back on.
01
Passenger Side Head Banjo Bolt
Below turbo inlet / feeds turbo AND AVCS intake solenoid
Most Critical
This is the screen that kills turbos. Located on the passenger side cylinder head below the turbo inlet pipe. The oil supply from this banjo bolt feeds both the turbo oil inlet AND the passenger side AVCS intake solenoid. A fully clogged screen here starves the turbo of oil pressure at startup. The first symptom is often the AVCS code (P0011) but turbo bearing damage is already occurring. This screen is the first thing we look at on any EJ turbo rebuild that came in with AVCS codes in the history.
02
Driver Side Head Banjo Bolt
Feeds driver side AVCS intake solenoid
The driver's side banjo bolt screen feeds the driver side AVCS intake solenoid and cam journals. This one does not directly feed the turbo but a clogged driver side screen causes P0021 codes and cam timing faults. Access is much harder than the passenger side -- it sits near the timing belt cover and often requires timing component removal for proper access. When we rebuild an EJ turbo, we document accessible screen condition and flag inaccessible ones for the owner to address during the next timing service.
03
OCV Solenoid Internal Screens
Inside each AVCS Oil Control Valve solenoid
Each AVCS Oil Control Valve solenoid has its own internal screen at the oil inlet port. These are separate from the banjo bolt screens above. Clogged OCV screens produce symptoms identical to a failed solenoid -- erratic cam timing, codes, and rough running -- but replacing the solenoid without cleaning the screen results in the same codes immediately. OCV internal screens are inspected when we have AVCS codes on a turbo rebuild.
04
Exhaust AVCS Supply Passages
Internal head drillings -- EJ207 / EJ257 with exhaust AVCS
JDM EJ207 and USDM EJ257 engines have exhaust-side AVCS in addition to intake AVCS. The exhaust AVCS solenoids are fed through internal drillings in the head castings -- not via external banjo bolts with accessible screens. Restriction here is harder to diagnose and produces P0024 codes. The exhaust OCV solenoids are located on the underside of the heads at the front corners. If exhaust AVCS codes persist after new solenoids and a clean oil system, the internal head passages require professional cleaning.
DTC Reference: P0011 = Intake cam bank 1 advanced. P0021 = Intake cam bank 2 advanced. P0024 = Exhaust cam bank 2 advanced. Any of these codes on an EJ turbo warrants AVCS screen inspection before turbo work proceeds.
Platform Coverage

Every Turbocharged
Subaru We Rebuild

Every turbocharged Subaru from the first USDM WRX through current production is supported. The turbo varies by engine code, model year, and market -- the table below covers every configuration.

Model / Year Engine Turbo Market Bearing Notes
WRX 2002-2007EJ205 2.0LMitsubishi TD04LUSDMJournalSee MHI page for TD04L rebuild detail
WRX 2009-2014EJ255 2.5LIHI VF52USDMJournal14411AA800 -- most common WRX rebuild
WRX 2015-2021FA20DIT 2.0LIHI VF57USDMJournal14411AA830 -- Direct injection EJ replacement
STI 2004-2006EJ257 2.5LIHI VF39USDMJournal14411AA572 -- P18 single scroll
STI 2007EJ257 2.5LIHI VF43USDMJournal14411AA620 -- enlarged wastegate vs VF39
STI 2008-2021EJ257 / EJ257B 2.5LIHI VF48USDMJournal14411AA700 -- most common STI rebuild
Legacy GT 2005-2007EJ255 2.5LIHI VF40USDMJournal14411AA530
Legacy GT 2008-2012EJ255 2.5LIHI VF54USDMJournal14411AA760
Forester XT 2004-2008EJ255 2.5LIHI VF40 / VF45USDMJournalConfirm year for exact variant
JDM WRX EJ20 earlyEJ20 2.0LIHI VF22 / VF23 / VF24JDMBallLargest VF flow / rally heritage
JDM WRX EJ20 midEJ20 2.0LIHI VF28 / VF29 / VF35JDMBallVF28 STI V5 / VF35 Type RA small housing
JDM WRX / Legacy 2004+EJ20 2.0LIHI VF45JDMJournal14411AA650
JDM STI EJ207 V5-V6EJ207 2.0LIHI VF28JDMBall14411AA200
JDM STI EJ207 V7-V9EJ207 2.0LIHI VF30 / VF34JDMJournal / BallVF30 journal / VF34 ball bearing
JDM STI Spec C 2003+EJ207 2.0LIHI VF36JDMBall14411AA490 -- Ti shaft twin scroll P25
JDM STI V8/V9 Spec CEJ207 2.0LIHI VF37JDMJournal14411AA542 -- twin scroll P25
JDM STI 2008-2014EJ207 2.0LIHI VF49JDMJournal14411AA690 -- twin scroll
JDM Legacy GTEJ20 2.0LIHI VF38JDMBall14411AA560 -- Ti shaft twin scroll P18
JDM Forester STIEJ207 2.0LIHI VF41JDMJournal14411AA610
Part Number Reference

Find Your Part Number

Search by Subaru OEM part number, IHI VF model, engine code, or model year. Subaru uses the 14411-XXXXXX format for all OEM turbocharger part numbers.

Showing -- results
Subaru OEM Part # IHI Model Engine Application Notes
14411AA800VF52EJ255 2.5L2009-2014 Subaru WRX (USDM)Journal / Single Scroll P18
14411AA800DVF52EJ255 2.5L2009-2014 Subaru WRX (USDM)Journal / Single Scroll P18
14411AA830VF57FA20DIT 2.0L2015-2021 Subaru WRX (USDM)Journal / FA20DIT direct injection
14411AA572VF39EJ257 2.5L2004-2006 Subaru WRX STI (USDM)Journal / Single Scroll P18
14411AA620VF43EJ257 2.5L2007 Subaru WRX STI (USDM)Journal / Enlarged wastegate
14411AA700VF48EJ257 / EJ257B 2.5L2008-2021 Subaru WRX STI (USDM)Journal / Single Scroll P18
VA440057VF48EJ257 2.5L2008-2021 STI (USDM) -- IHI internal codeIHI Internal Code
14411AA530VF40EJ255 2.5L2005-2007 Subaru Legacy GT (USDM)Journal / Single Scroll P18
14411AA760VF54EJ255 2.5L2008-2012 Subaru Legacy GT (USDM)Journal / Single Scroll P18
14411AA650VF45EJ20 / EJ255 2.0LJDM WRX / Legacy EJ20 2004+ / Forester XTJournal / Single Scroll P18
14411AA070VF22EJ20 2.0LJDM WRX / STI EJ20 early -- largest VFBall Bearing / P20 single scroll
14411AA130VF23EJ20 2.0LJDM WRX EJ20Ball Bearing / P20 single scroll
14411AA150VF24EJ20 2.0LJDM WRX EJ20 / Rally / autoBall Bearing / P18 single scroll
14411AA200VF28EJ207 2.0LJDM STI Version 5 EJ207Ball Bearing / P20 single scroll
14411AA220VF29EJ20 2.0LJDM WRX EJ20 improved compressorBall Bearing / P18 single scroll
14411AA443VF35EJ20 2.0LJDM WRX Type RA fast spoolJournal / P15 small housing
14411AA373VF30EJ207 2.0LJDM STI EJ207 V7-V9Journal / Single Scroll P18
14411AA340VF34EJ207 2.0LJDM STI EJ207 V7-V9 ball bearing versionBall Bearing / Single Scroll P18
14411AA490VF36EJ207 2.0LJDM STI Spec C 2003+ -- Ti shaft twin scrollBall Bearing / Twin Scroll P25
14411AA542VF37EJ207 2.0LJDM STI V8/V9 Spec CJournal / Twin Scroll P25
14411AA690VF49EJ207 2.0LJDM STI 2008-2014Journal / Twin Scroll
14411AA560VF38EJ20 2.0LJDM Legacy GT Ti shaft twin scrollBall Bearing / Twin Scroll P18
14411AA610VF41EJ207 2.0LJDM Forester STIJournal / Single Scroll P18
14411AA900VF60VariousSubaru Levorg / JDM applicationsJournal Bearing
Common Failure Modes

Why Subaru Turbos
Fail

Subaru turbo failures almost always trace back to engine-specific issues unique to the EJ and FA platforms. Understanding the root cause is the difference between a successful rebuild and the same failure repeated.

01
AVCS Banjo Bolt Screen Restriction
The most common preventable Subaru turbo failure. The banjo bolt screens in the AVCS oil supply lines accumulate varnish from degraded oil and restrict -- or fully block -- oil flow to the turbo and cam journals. The passenger side screen is the most critical because it feeds both the turbo and the AVCS intake solenoid. The first symptom is typically a P0011 AVCS code. By the time the code appears, the turbo has already been running starved. Oil change intervals and fluid quality are the only prevention. The screens are on the car, not the turbo -- we cannot inspect them during a rebuild. What we can do is assess the CHRA at teardown for oil starvation evidence and include that finding in the rebuild report. If we see bearing wear consistent with restricted oil flow, we flag it and recommend getting the screens out before reinstalling. Both Subaru TSBs on the subject and the entire Subaru specialist community recommend removing these screens on every turbocharged EJ.
02
Oil Consumption and Turbo Seal Failure
The EJ255 and EJ257 are known for oil consumption -- some engines consume a quart every 1,000 miles, particularly on modified engines running aggressive cam timing or boost. Low oil level starves the turbo bearing system at high RPM and under sustained boost. The flat boxer configuration means the engine holds oil differently than an inline engine, and the turbo drain lines sit at unique angles that can cause pooling if the drain is even slightly restricted. Oil in the intake tract and blue smoke under boost are the first indicators. Turbo seal inspection is part of every Subaru rebuild.
03
EJ257 / EJ255 Ringland Failure Debris
The EJ255 and EJ257 use cast pistons with thin upper ring lands. Under detonation from pump gas, aggressive timing, or lean conditions, the ring land between the first and second ring cracks. Compression drops on that cylinder, blowby increases, and oil consumption spikes. The cracked piston generates debris that circulates through the oiling system. Turbos on engines that have experienced a ringland failure see contaminated oil and often arrive with debris in the CHRA. A ringland failure that has not been fully addressed before the turbo rebuild will damage the new bearings immediately.
04
Cold Boost on Journal Bearing VF Units
The USDM VF39, VF43, VF48, VF52, and VF54 are all journal bearing turbos. Journal bearings rely on a pressurized oil film between the shaft and bearing surface. On a cold EJ engine, the oil is thick and slow to reach full pressure. The Subaru EJ platform runs high-viscosity oil through the narrow AVCS passages even on a warm engine -- on a cold engine with any screen restriction, the combination is destructive. Hard acceleration or full boost demand on a cold EJ is the fastest way to score a journal bearing. Even five minutes of easy warmup makes a meaningful difference.
05
FA20DIT Oil Feed Path Issues
The 2015+ WRX FA20DIT replaced the EJ with a direct-injection turbocharged boxer. The VF57 on the FA20DIT is a journal bearing single scroll unit, but the FA20DIT has its own oil feed path characteristics different from the EJ. Direct injection engines are also known for increased intake valve carbon buildup that can restrict crankcase ventilation -- affecting PCV function and oil pressure stability. FA20DIT turbos with oil consumption issues should be assessed for PCV condition before the rebuild is finalized. The good news is the FA20DIT eliminated the AVCS banjo bolt screen problem of the EJ generation.
06
Head Gasket Coolant Contamination
Head gasket failure on EJ engines -- most common on the naturally aspirated EJ25 but also present on turbocharged variants -- pushes coolant into the oil system. Coolant-contaminated oil loses its film strength immediately, causing bearing failure throughout the engine including the turbo. The telltale signs are milky oil, sweet smell from the exhaust, and coolant level drop without visible external leaks. A Subaru turbo rebuild on an engine with a compromised head gasket is a short-term fix. The head gasket situation must be resolved before any turbo rebuild makes economic sense.
Common Questions

Frequently Asked

The AVCS screens are small mesh filters -- roughly the size of a pencil eraser -- installed inside the banjo bolts that supply oil to the AVCS Oil Control Valve solenoids on the cylinder heads. There are multiple screens: one at the passenger side head (which also feeds the turbo oil supply), one at the driver side head, and internal screens inside each OCV solenoid body. They accumulate varnish deposits from degraded oil and can restrict or fully block oil flow to the turbo and cam journals. Because the screens are on the engine and not on the turbo, we do not inspect them during a rebuild -- we only have the turbo. What we assess at teardown is the CHRA condition for evidence of oil starvation, which tells us whether restricted oil flow was likely the cause. The location details in the section above are there so you know what to look for and address on the engine side.
Yes -- remove them. Subaru issued TSB 02-97-05 specifically for the AVCS screens and TSB 02-103-07 for the turbo oil feed screen. Both TSBs recommend removal. NASIOC, IWSTI, and every major Subaru specialist forum has the same answer: pull them out. A thread on NASIOC is literally titled "Remove those banjo bolt filters." The case is straightforward -- the screens protect against debris in an oil system that should not have debris if the oil is being changed properly. A clogged screen on a well-maintained engine is a worse outcome than no screen at all. The only argument for keeping them is on a brand new engine with unknown contamination risk, and even then most builders pull them before first startup. If your car still has the screens in, removing them is one of the most important preventive maintenance items on a turbocharged EJ.
They are connected -- fix the root cause first, then the turbo. P0011 on an EJ turbo means the passenger side intake AVCS is not responding correctly. The passenger side AVCS banjo bolt also feeds the turbo. If that screen is clogged, replacing the turbo without addressing the screen means the new turbo starves from day one. The correct sequence is: inspect and address the AVCS screens, confirm oil pressure at the turbo inlet, then rebuild the turbo. Shipping the turbo to us is the right first step -- we inspect the CHRA and include a screen status note in the report so you know exactly what needs to happen on the engine side before the rebuilt turbo goes back on.
Yes, significantly. The 2002-2007 USDM WRX uses a Mitsubishi TD04L turbocharger on the EJ205 2.0L engine -- see our MHI turbo page for that rebuild. The STI from 2004 onward uses IHI VF series turbos on the EJ257 2.5L engine. The WRX moved to IHI in 2009 with the EJ255 2.5L and VF52. So the turbo manufacturer changed between WRX and STI, and again when the WRX moved to 2.5L. If you have a 2002-2007 WRX, your turbo is a TD04L. If you have a 2004-2021 STI, your turbo is IHI VF. If you have a 2009-2014 WRX, your turbo is IHI VF52. If you have a 2015-2021 WRX, your turbo is IHI VF57. When in doubt, send us the year, model, and trim and we will confirm.
Drain any residual oil from the oil inlet and outlet ports. Plug all ports. Double-box with foam or bubble wrap padding on all sides. Ship via UPS or FedEx to 37833 Pineapple Ave Unit A, Dade City, FL 33523. Include the year, model (WRX or STI), engine code if known, and any symptoms or codes that were present before removal. For JDM imports include the JDM version number if known (Version 7, V8, V9, V10 etc.) -- it helps us pull the right components before teardown. Contact us before shipping and we will send a receiving confirmation.
Yes. We work with Subaru performance shops and dealers nationwide. VF48 and VF52 are our two highest-volume IHI units and we stock components for fast turnaround on both. If you are a shop sending multiple Subaru turbos regularly, contact us about wholesale pricing and shop accounts. Turnaround on stocked units is typically 3-5 business days after receiving.
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Ready to Rebuild?

Start your rebuild request in our repair system. VF48 and VF52 parts stocked for fast turnaround. Every EJ teardown report includes oil starvation assessment and AVCS screen removal recommendation. In-house VSR balancing since 2008.

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sales@theboostlab.com theboostlab.com Dade City, FL