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Lexus GS: FSE Direct Injection Intake Valve Carbon Buildup (GS300/GS350)

FSE Direct Injection Intake Valve Carbon Buildup (GS300/GS350) is a common engine fault on the Lexus GS on the 2005–2011 cars, and we rate it major. Putting it right costs $900 to $2,200 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 19 documented faults on the Lexus GS.

Vehicle
Lexus GS
Engine
3.0L / 3.5L
Years
2005–2011
Fuel
petrol
System
Engine

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

All Lexus GS faults19 documented faults on this model

What you are looking at

No photograph available

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

What goes wrong

The 3GR-FSE 3.0L (GS300) and 2GR-FSE 3.5L (GS350) in the S190 GS both use Lexus D-4S or D-4 direct injection without supplementary port injection, allowing carbon deposits from PCV oil vapour to accumulate on intake valve stems and seat faces. The 3GR-FSE is particularly susceptible due to its narrower port geometry. Carbon accumulation restricts intake airflow unevenly across cylinders, producing misfires and performance degradation. Cleaning requires intake manifold removal and mechanical blasting.

What you would notice

  • Intermittent misfire or rough idle, more pronounced when cold
  • Loss of power and throttle response at partial load
  • Increased fuel consumption with no other identifiable cause
  • P030x misfire codes stored without corresponding ignition or injector fault

How to check it

Where to look. Intake valve faces and stems, cylinder head intake ports

  1. Request a bore-scope inspection of intake valves through the intake ports before purchase.

  2. Check for rough cold-start behaviour during the test drive.

  3. Vehicles above 90,000 km without documented valve cleaning should be assumed to have significant deposits.

  4. Inspect the air intake tract for oily residue which indicates PCV blow-by contributing to deposits.

Parts involved: Intake manifold, PCV / oil separator.

What it costs to put right

$900 to $2,200 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

  • “Has an intake valve carbon clean been carried out, and at what odometer?”
  • “Has the vehicle suffered any misfire or Check Engine light events?”

Now check the Lexus GS 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.

Lexus GS buyer questions

Is fse direct injection intake valve carbon buildup (gs300/gs350) serious on a Lexus GS?

We rate it major and common on the Lexus GS. The 3GR-FSE 3.0L (GS300) and 2GR-FSE 3.5L (GS350) in the S190 GS both use Lexus D-4S or D-4 direct injection without supplementary port injection, allowing carbon deposits from PCV oil vapour to accumulate on intake valve stems and seat faces. The 3GR-FSE is particularly susceptible due to its narrower port geometry. Carbon accumulation restricts intake airflow unevenly across cylinders, producing misfires and performance degradation. Cleaning requires intake manifold removal and mechanical blasting.

How much does it cost to fix on a Lexus GS?

$900 to $2,200 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 Lexus GS years are affected?

Our research records this fault on the 2005–2011 Lexus GS. 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?

Request a bore-scope inspection of intake valves through the intake ports before purchase. Check for rough cold-start behaviour during the test drive. Vehicles above 90,000 km without documented valve cleaning should be assumed to have significant deposits. Inspect the air intake tract for oily residue which indicates PCV blow-by contributing to deposits. Look here: Intake valve faces and stems, cylinder head intake ports