Thinking about buying a used Subaru B4 (1998–2020) in New Zealand? We've documented 42 known faults for this model spanning engine, suspension, transmission, and body & rust. Each researched and verified before it's published. The most serious issues here are rated critical. Two are set out in full below — the rest, with the symptoms, repair costs and checks for each, are free with an account.
42
Documented faults
Critical
Most serious
$600–$2,000
Typical repair
8
Systems covered
Known Subaru B4 faults
Every fault below is documented specifically for this model — researched and verified before it’s published.
01EJ255 turbo piston ringland cracking
CriticalCommonEngine $4,000–$9,000 to fix
The turbocharged EJ255 fitted to the Legacy GT (BP generation) is prone to piston ringland cracking, the same well-documented failure mode seen in WRX and Forester XT of the same era. Ringlands crack when the engine is run on low-octane fuel, allowed to detonate, or pushed hard without proper warm-up. Once a ringland breaks, oil consumption spikes, compression drops and blue smoke is produced under load, typically requiring short-block replacement or a full rebuild.
Symptoms to notice
Sudden increase in oil consumption exceeding 1 litre per 2000 km
Blue smoke on hard acceleration or overrun
Rough idle and misfire on the cylinder with the damaged ringland
Loss of power and poor throttle response
Low compression reading on one or more cylinders
What to check
Check for blue smoke under hard acceleration. Review oil consumption history. Inspect the air filter and intercooler piping for oil contamination. Confirm whether 98-octane fuel has always been used. If a workshop inspection is possible: Perform a compression test across all four cylinders — values should be within 10% of each other and above 150 psi.
Where to look: Pistons within the EJ255 turbocharged engine block
Ask the seller
“What octane fuel has been used consistently?”
“Has the car ever been tuned or had an aftermarket ECU map applied?”
“What is the current oil consumption rate between changes?”
02Electric power steering rack rattle and knock
MinorOccasionalSuspension $1,200–$2,700 to fix
BS/BN Legacy models with electric power steering can develop a rattle or clunk from the steering rack, typically felt and heard over small bumps and road irregularities. The fault is linked to worn inner tie rod end preload bushes within the rack assembly and general internal rack wear. Subaru released a service bulletin for some markets recommending rack inspection and replacement where worn. The noise can be confused with suspension noise but tracks directly with steering inputs.
Symptoms to notice
Rattling or clunking from the steering column area over bumps
Knock felt through the steering wheel on rough or chip-sealed roads
Noise correlates with steering inputs rather than purely with road texture
Increased play in the straight-ahead steering position
What to check
Road test on a rough or chip-sealed road while making small steering corrections and listen for rack knock. With the vehicle stationary and engine running, gently rock the steering wheel and listen for internal rack knock. With the car raised, have a helper rock the wheel while you feel the inner tie rod joints for play.
Where to look: Electric power steering rack, centred on the firewall behind the engine
Ask the seller
“Has any knocking or rattling been noticed from the steering on rough roads?”
“Has the steering rack or tie rods been inspected recently?”
“Has a Subaru dealer or independent workshop flagged any EPS faults?”
EngineCritical
EngineCritical
EngineCritical
EngineCritical
EngineCritical
EngineCritical
SuspensionCritical
EngineCritical
TransmissionMajor
TransmissionMajor
EngineMajor
TransmissionMajor
EngineMajor
EngineMajor
TransmissionMajor
EngineMajor
Body & RustMajor
SuspensionMajor
EngineMajor
EngineMajor
EngineMajor
EngineMajor
EngineMajor
SuspensionMajor
EngineMajor
EngineMajor
SuspensionMajor
SuspensionMajor
EngineMajor
ElectricalMajor
Fluid LeaksMajor
SuspensionMajor
EngineMajor
SuspensionMajor
SuspensionMajor
SuspensionMajor
BrakesMajor
ElectricalMinor
CoolingMinor
SuspensionMinor
40 more documented faults on the Subaru B4
Symptoms, what to check, where to look and what to ask the seller — for every fault above. Free with an account, no card needed. One account covers one vehicle, so make it the car you’re actually looking at.
This page covers the model. Enter the plate of the actual car you’re looking at and see its year, engine, safety rating and register flags — free, no account needed.
Like any used car, it depends on the specific example and its service history. Across the 42 documented faults for the Subaru B4, the recurring problem areas are engine, suspension, and transmission. A Subaru B4 with a full service history and no signs of the issues listed on this page can be a sound buy but each one needs to be checked individually before you commit.
What are the most common problems with a used Subaru B4?
+
We've catalogued 42 known faults for the Subaru B4, covering engine, suspension, and transmission. Two are written out in full on this page. The rest — with the symptoms to notice, what to inspect, and typical repair costs for each — are free once you create an account.
How much do repairs cost on a Subaru B4?
+
Most single repairs on the Subaru B4 fall between $600–$2,000 at NZ independent-workshop rates. Some of the 42 documented faults cost less and a few cost considerably more, and no one car needs them all. Knowing which ones to look for before you view is what lets you negotiate the price down or walk away.
Should I get a pre-purchase inspection on a Subaru B4?
+
Yes. A Subaru B4 inspection focused on its known weak points is the single best way to avoid an expensive mistake. KickTyres gives you a guided, model-specific inspection plus a market valuation and negotiation figure for $17.90 far less than the cost of missing one of the faults on this page.