MajorCommonEngine

Subaru Forester: EJ25 AVCS Oil Control Solenoid Failure

EJ25 AVCS Oil Control Solenoid Failure is a common engine fault on the Subaru Forester on the 2004–2013 cars, and we rate it major. Putting it right costs $280 to $750 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
Engine: EJ25
Years: 2004–2013
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 Cylinder head yet. We would rather show none than show a picture of a different part.

What goes wrong

The Active Valve Control System (AVCS) on EJ25 engines uses oil-pressure-actuated cam phasers controlled by solenoid valves mounted on the cylinder heads. The solenoids are sensitive to oil sludge and varnish deposits that accumulate from extended service intervals or short-trip driving, causing the solenoid pintle to stick or the oil passage screens to block. When the solenoid cannot modulate oil pressure correctly, the cam phaser either locks in a fixed position or oscillates erratically, triggering cam timing fault codes and causing driveability problems especially during cold starts when oil viscosity is highest.

What you would notice

Check engine light with codes P0011, P0021, P000A, or P000B stored in the ECU
Rough or lumpy idle, particularly during cold start warm-up in temperatures below 10 degrees Celsius
Hesitation and reduced power output between 2,000 and 4,000 rpm under moderate throttle

How to check it

Where to look. AVCS solenoids mounted at the front of each cylinder head, accessible from the top of the engine bay

With the engine at operating temperature, unplug each solenoid connector in turn and listen for a change in idle quality. Inspect the oil filler cap and dipstick for sludge indicating poor oil maintenance. If a workshop inspection is possible: Scan for OBD-II codes P0011 (intake cam timing over-advanced, bank 1), P0021 (bank 2), or related P000A/P000B codes. Remove the solenoid and inspect the screen filter for blockage.

Parts involved: Cylinder head.

What it costs to put right

$280 to $750 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

“Has the check engine light ever been on, and has the car been scanned for cam timing codes?”
“What oil change interval has been followed, and what grade of oil has been used?”

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 ej25 avcs oil control solenoid failure serious on a Subaru Forester?

We rate it major and common on the Subaru Forester. The Active Valve Control System (AVCS) on EJ25 engines uses oil-pressure-actuated cam phasers controlled by solenoid valves mounted on the cylinder heads. The solenoids are sensitive to oil sludge and varnish deposits that accumulate from extended service intervals or short-trip driving, causing the solenoid pintle to stick or the oil passage screens to block. When the solenoid cannot modulate oil pressure correctly, the cam phaser either locks in a fixed position or oscillates erratically, triggering cam timing fault codes and causing driveability problems especially during cold starts when oil viscosity is highest.

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

$280 to $750 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 2004–2013 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.