Common faults below

Infiniti Engine Carbon Cleaning

What we see most on Infiniti engines, what causes it, and which clean fixes it. Every job starts with a scan and a quote at our Kings Park workshop.

Free scanbefore any work
Kings ParkSydney workshop
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Which Infiniti do you have?

Infiniti left Australia in 2020, so every one still here is a used car without a local dealer network behind it — which changes what these pages are for.

If you have a petrol Q50, Q60 or QX, it depends on the engine. The 3.0-litre twin-turbo V6, the 2.0-litre turbo and the QX80’s V8 inject fuel into the cylinder, so the intake valves never get washed. After this many years there is usually a solid crust on them rather than a light film. The 3.7-litre V6 sprays fuel onto the valves, so it rarely needs that work.

If you have the 2.2-litre diesel Q50, it carries a particulate filter and an EGR circuit, and both are now at the age and kilometres where they need attention.

Getting these looked after is harder than it should be, so we will tell you plainly what we can and cannot do for yours.

Common Infiniti carbon problems

What we see

If you drive a petrol Infiniti

Petrol

Intake Valve Carbon on the Petrol V6

The 3.0-litre twin-turbo V6, the 2.0-litre turbo and the QX80’s V8 spray fuel into the cylinder, so nothing washes the back of the intake valves. The 3.7-litre V6 sprays fuel onto the valves, so it rarely builds this.
Oil vapour drawn through the breather bakes onto the hot valve and hardens.
With no local dealer network, most of these cars have gone years without anyone looking at the intake side.

Rough idle, worst from cold.
Hesitation off the line and a soft mid-range.
Misfire codes (P0300–P0308) with no ignition fault found.
Fuel consumption up with no change in driving.

Walnut blasting once the deposits have hardened — the intake comes off and each port is cleaned mechanically.
We show you the valves before quoting so you can see what you are paying for.

Fixed by

Walnut Blasting

Quoted after the free scan

See the service →

If you drive a diesel Infiniti

Diesel

Particulate Filter on the 2.2 Diesel

A regeneration needs a sustained run, and these cars mostly do suburban kilometres now.
Every interrupted regeneration leaves the filter fuller than before.
At this age the injectors usually contribute as well, loading it faster than driving alone would.

DPF warning, then reduced power and limp mode.
Warnings arriving closer together.
A hot smell after parking and worse fuel economy.
Codes in the P2002 and P2452–P2463 range.

Where we can, we clean the filter on the car — nothing removed, cut open or replaced. If it has to come off, it gets a three-stage clean and new gaskets, quoted first.
We look at the fuel side in the same visit, because on a car this age that is usually what has loaded it.
Nothing is deleted. A car without its emissions equipment is not roadworthy in New South Wales.

Fixed by

DPF Cleaning

From $715

See the service →

Diesel

EGR and Intake Soot on the Diesel

The EGR valve feeds sooty exhaust gas into the intake, where it meets oil mist from the breather.
Years of short trips leave a greasy deposit narrowing the runners.
Nothing in normal suburban use gets it hot enough to burn away.

Throttle that feels muffled rather than sharp.
Smoke under load that was not there a year ago.
An unsettled idle with EGR flow codes stored (P0401, P0402).

We clean the EGR circuit and the intake manifold so the airway is clear again.
On an orphaned car this is a low-cost way to find out whether it is still worth running.

Fixed by

EGR & Intake Manifold Cleaning

Quoted after the free scan

See the service →

If you drive a hybrid Infiniti

Applies to any Infiniti

Any Infiniti

A Car Without a Dealer

With no local network, faults on these cars get treated one at a time by whoever will look at them.
On a car with distance behind it the intake, the fuel side and the exhaust side are dirty together.
That is why the same complaint keeps coming back after each visit.

The same code returning after being cleared.
A car that has been to several workshops without anything sticking.
Several unrelated-looking faults over a short period.

A full engine carbon clean treats the intake and exhaust sides together, which is the right scope when the whole engine is dirty rather than one part.
We scan first, tell you what we found, and give you the price before starting — including when the answer is that we cannot help.

Fixed by

Full Engine Carbon Clean

From $715

See the service →

Keeping your Infiniti clean

Prevention

To keep a diesel Infiniti Q50 clean, give the 2.2 a steady run of about half an hour every week, or an hour every fortnight, Nas’s rule of thumb, not just suburban kilometres. At this age the injectors usually help load the particulate filter too. The petrol 3.0-litre twin-turbo V6, 2.0-litre turbo and QX80 V8 build carbon on the intake valves instead. After this many years the carbon is usually a solid crust rather than a light film. The 3.7-litre V6 sprays fuel onto its valves, so it rarely builds that crust.

If the diesel shows a DPF warning or the throttle feels muffled rather than sharp, book a time at our Kings Park workshop. We scan it free first, tell you what it needs, and quote before any work starts. That may be an EGR and intake clean or an on-car DPF clean, with the fuel side checked in the same visit. On a direct-injection petrol it may be walnut blasting.

I am very pleased with the service I was provided. Nasir is knowledgeable professional and honest , the diagnostic was accurate, he kept me fully informed and after carbon cleaning and fixing other mechanical issues my car no longer has lumpy idle and throttle response is so much sharper. Overall extremely happy. Highly recommended.

Matthew · Google review

Before any engine work on your Infiniti, search your VIN on the government vehicle recalls site. Recall repairs are free, so check there first.

Act when the warnings bunch up. On the 2.2 diesel, DPF warnings arriving closer together are a sign the filter is blocking. Every interrupted self-clean (DPF burn) leaves it fuller, so book in before limp mode.
Get the intake checked if nobody has. With no local dealer network left, the intake side can go years without anyone looking at it. On the direct-injection petrols, that is where the carbon builds.
Get the whole engine looked at once. Faults on these cars tend to get treated one at a time by whoever will look at them. On a car with distance behind it, the intake, fuel and exhaust sides are dirty together. That is why the same complaint keeps coming back.

Book your Infiniti in

Get a free quote

Tell us the model, the kilometres and what it is doing. We will scan it and tell you which clean it needs, and what it costs, before any work starts.

Get a Free Quote Call Nas — 0455 455 644