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Subaru Levorg: FB16 DI Intake Valve Carbon Buildup

FB16 DI Intake Valve Carbon Buildup is a common engine fault on the Subaru Levorg on the 2014–2020 cars, and we rate it major. Putting it right costs $750 to $1,600 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 13 documented faults on the Subaru Levorg.

Vehicle
Subaru Levorg
Engine
FB16
Years
2014–2020
Fuel
petrol
Gearbox
cvt
System
Engine

This page covers the Subaru Levorg 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 Levorg faults13 documented faults on this model

What you are looking at

No photograph available

We do not hold a verified photograph of the Intake manifold yet. We would rather show none than show a picture of a different part.

What goes wrong

The FB16 1.6T direct injection engine does not wash intake valves with fuel, allowing combustion blowby gases to deposit carbon on valve stems and ports. Buildup accelerates significantly past 50,000 km and causes rough cold start, idle misfire, and throttle hesitation under light load. Chemical induction cleaners cannot reach DI valves; walnut blasting with intake manifold removed is the only effective remedy. Grey imports arriving in NZ at 60,000–100,000 km are commonly at or past onset mileage with no prior cleaning on record.

What you would notice

  • Rough or lumpy idle when cold, especially below 10 degrees C
  • Misfires or stumble on cold start before engine warms
  • Hesitation under light throttle from rest
  • Reduced low-RPM power when engine is cold
  • Occasional misfire check engine codes P0300 to P0304

How to check it

Where to look. Intake valves and ports within the cylinder head, accessed via intake manifold removal on the top of the engine

  1. Look for heavy grey-black carbon deposits coating the back face and stem of each intake valve.

  2. Ask for any documented walnut blast or induction service in the service history.

  3. Request borescope inspection of all four intake ports with manifold removed.

Parts involved: Intake manifold.

What it costs to put right

$750 to $1,600 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 an intake valve carbon clean or walnut blast ever been performed?”
  • “Is there a borescope inspection on record showing valve condition?”
  • “Does the car idle smoothly on cold first start from overnight?”

Now check the Subaru Levorg 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 Levorg buyer questions

Is fb16 di intake valve carbon buildup serious on a Subaru Levorg?

We rate it major and common on the Subaru Levorg. The FB16 1.6T direct injection engine does not wash intake valves with fuel, allowing combustion blowby gases to deposit carbon on valve stems and ports. Buildup accelerates significantly past 50,000 km and causes rough cold start, idle misfire, and throttle hesitation under light load. Chemical induction cleaners cannot reach DI valves; walnut blasting with intake manifold removed is the only effective remedy. Grey imports arriving in NZ at 60,000–100,000 km are commonly at or past onset mileage with no prior cleaning on record.

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

$750 to $1,600 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 Levorg years are affected?

Our research records this fault on the 2014–2020 Subaru Levorg. 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?

Look for heavy grey-black carbon deposits coating the back face and stem of each intake valve. Ask for any documented walnut blast or induction service in the service history. Request borescope inspection of all four intake ports with manifold removed. Look here: Intake valves and ports within the cylinder head, accessed via intake manifold removal on the top of the engine