MajorCommonEngine

Subaru Forester: EJ Engine PCV System Failure Causing Oil Consumption

EJ Engine PCV System Failure Causing Oil Consumption is a common engine fault on the Subaru Forester on the 1997–2012 cars, and we rate it major. Putting it right costs $200 to $1,200 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 50 documented faults on the Subaru Forester.

Vehicle: Subaru Forester
Years: 1997–2012
Fuel: petrol
System: Engine

This page covers the Subaru Forester as a model. Some faults only affect particular engines or build years — enter a plate below to narrow the list to one car.

All Subaru Forester faults50 documented faults on this model

What you are looking at

No photograph available

We do not hold a verified photograph of the PCV / oil separator yet. We would rather show none than show a picture of a different part.

What goes wrong

The positive crankcase ventilation (PCV) system on EJ-series flat-four engines is prone to blockage and valve failure, particularly from 120,000 km onward. A restricted or failed PCV valve allows crankcase pressure to build, forcing oil past piston rings and valve stem seals and into the combustion chamber. Symptoms can mimic head gasket failure. On SG turbo models, a blocked oil separator in the PCV circuit causes oil to be drawn into the intake upstream of the turbo, contaminating the intercooler and leading to carbon buildup on intake valves.

What you would notice

Blue-grey smoke on startup or overrun, clearing after warmup
Oil consumption above 500 ml per 1,000 km without visible external leak
Oil residue inside air intake or intercooler piping
Fouled spark plugs with oil deposits on electrodes

How to check it

Where to look. PCV valve and separator on rocker cover, hoses routed to intake manifold

Inspect the PCV hoses and separator unit for cracking, oil saturation, or collapse.
Check all four spark plugs for oily or carbon-fouled electrodes.
On turbo models, disconnect the lower intercooler hose and inspect for oil pooling.
Check oil level drop over a known mileage interval.
Remove the oil filler cap with the engine idling and hold your hand above the opening — a strong puff of vapour indicates PCV system blockage.

Parts involved: PCV / oil separator.

What it costs to put right

$200 to $1,200 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

Ask the seller

“What is the approximate oil consumption — how often is oil topped up between changes?”
“Has the PCV system ever been inspected or the valve replaced?”
“Has blue smoke been noticed on cold starts or when lifting off the throttle?”

Now check the Subaru Forester you are actually looking at

Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.

Not sure what you would be paying for? See what a full KickTyres check includes.

Where this comes from

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.

Subaru Forester buyer questions

Is ej engine pcv system failure causing oil consumption serious on a Subaru Forester?

We rate it major and common on the Subaru Forester. The positive crankcase ventilation (PCV) system on EJ-series flat-four engines is prone to blockage and valve failure, particularly from 120,000 km onward. A restricted or failed PCV valve allows crankcase pressure to build, forcing oil past piston rings and valve stem seals and into the combustion chamber. Symptoms can mimic head gasket failure. On SG turbo models, a blocked oil separator in the PCV circuit causes oil to be drawn into the intake upstream of the turbo, contaminating the intercooler and leading to carbon buildup on intake valves.

How much does it cost to fix on a Subaru Forester?

$200 to $1,200 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.

Which Subaru Forester years are affected?

Our research records this fault on the 1997–2012 Subaru Forester. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.

How do I check for it before I buy?

Inspect the PCV hoses and separator unit for cracking, oil saturation, or collapse. Check all four spark plugs for oily or carbon-fouled electrodes. On turbo models, disconnect the lower intercooler hose and inspect for oil pooling. Check oil level drop over a known mileage interval. Remove the oil filler cap with the engine idling and hold your hand above the opening — a strong puff of vapour indicates PCV system blockage. Look here: PCV valve and separator on rocker cover, hoses routed to intake manifold