MajorVery commonEngine

Lexus IS250: 4GR-FSE intake valve carbon buildup

4GR-FSE intake valve carbon buildup is a very common engine fault on the Lexus IS250 on the 2005–2013 cars, and we rate it major. Putting it right costs $800 to $2,000 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 6 documented faults on the Lexus IS250.

Vehicle: Lexus IS250
Engine: 4GR-FSE
Years: 2005–2013
Fuel: petrol
System: Engine

This page covers the Lexus IS250 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 IS250 faults6 documented faults on this model

What you are looking at

No photograph available

We do not hold a verified photograph for this fault yet. We would rather show none than show a picture of something else.

What goes wrong

The 4GR-FSE uses D-4 direct injection, which sprays fuel into the combustion chamber rather than the intake port. Without fuel washing the backs of the intake valves, carbon deposits accumulate over time causing rough idle, misfires, hesitation under load, and progressive power loss. Walnut-blasting or chemical induction cleaning is the established remedy. Very prevalent in AU/NZ examples above 80,000 km.

What you would notice

Rough idle, particularly when cold
Misfires under acceleration
Hesitation or stumble pulling away from rest
Reduced power compared to specification
P0300-series misfire diagnostic trouble codes
Fuel consumption increase

How to check it

Where to look. Intake valves and valve seats, cylinder head, both cylinder banks

Cold idle quality and any misfire codes are secondary indicators. Ask for documented intake cleaning history. If a workshop inspection is possible: Insert a borescope through the intake ports with intake manifold removed or throttle body off to inspect valve faces and stems for black carbon crust.

What it costs to put right

$800 to $2,000 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 intake ever been walnut-blasted or chemically induction-cleaned, and if so at what mileage?”
“Has the vehicle thrown any misfire or rough-idle codes?”
“Any history of hesitation on acceleration when the engine is fully warm?”

Now check the Lexus IS250 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 IS250 buyer questions

Is 4gr-fse intake valve carbon buildup serious on a Lexus IS250?

We rate it major and very common on the Lexus IS250. The 4GR-FSE uses D-4 direct injection, which sprays fuel into the combustion chamber rather than the intake port. Without fuel washing the backs of the intake valves, carbon deposits accumulate over time causing rough idle, misfires, hesitation under load, and progressive power loss. Walnut-blasting or chemical induction cleaning is the established remedy. Very prevalent in AU/NZ examples above 80,000 km.

How much does it cost to fix on a Lexus IS250?

$800 to $2,000 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 IS250 years are affected?

Our research records this fault on the 2005–2013 Lexus IS250. 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.