MajorCommonEngine

Mazda Mazda6: L5-VE 2.5 EGR valve sticking rough idle

L5-VE 2.5 EGR valve sticking rough idle is a common engine fault on the Mazda Mazda6 on the 2007–2013 cars, and we rate it major. Putting it right costs $160 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 48 documented faults on the Mazda Mazda6.

Vehicle: Mazda Mazda6
Engine: L5-VE
Years: 2007–2013
Fuel: petrol
System: Engine

This page covers the Mazda Mazda6 as a model. Some faults only affect particular engines or build years — enter a plate below to narrow the list to one car.

All Mazda Mazda6 faults48 documented faults on this model

What you are looking at

No photograph available

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

What goes wrong

The L5-VE 2.5L naturally aspirated engine in GH generation Mazda6 models is susceptible to carbon accumulation on the exhaust gas recirculation valve. Recirculated exhaust gas deposits carbon on the EGR valve pintle and seat over time, causing the valve to stick in a partially open position. Uncontrolled exhaust gas enters the intake manifold at idle, leaning out the mixture and causing rough or hunting idle, hesitation under light throttle, and occasional stalling. The condition is most pronounced when the engine is fully warm. The EGR valve is not equipped with a position sensor, meaning the control unit cannot detect incorrect positioning. Cleaning or replacement of the EGR valve resolves the condition.

What you would notice

Rough or lumpy idle when engine is fully warm
Idle hunting or surging at traffic lights
Hesitation under light throttle from low speeds
Occasional stalling at low speed or when coming to a stop
Check engine light with P0400 series EGR flow fault codes

How to check it

Where to look. EGR valve mounted on the intake manifold, upper engine area

Allow engine to reach full operating temperature and observe idle quality. Scan for P0400, P0401, or P0402 EGR flow codes. Inspect the intake manifold EGR port for carbon accumulation that may require cleaning. If a workshop inspection is possible: Remove and inspect EGR valve for carbon deposits preventing full valve closure.

Parts involved: EGR valve.

What it costs to put right

$160 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 EGR valve been cleaned or replaced and at what mileage?”
“Does the car idle smoothly when the engine is fully warm?”
“Any history of rough idle, surging, or stalling at low speed or at lights?”

Now check the Mazda Mazda6 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.

Mazda Mazda6 buyer questions

Is l5-ve 2.5 egr valve sticking rough idle serious on a Mazda Mazda6?

We rate it major and common on the Mazda Mazda6. The L5-VE 2.5L naturally aspirated engine in GH generation Mazda6 models is susceptible to carbon accumulation on the exhaust gas recirculation valve. Recirculated exhaust gas deposits carbon on the EGR valve pintle and seat over time, causing the valve to stick in a partially open position. Uncontrolled exhaust gas enters the intake manifold at idle, leaning out the mixture and causing rough or hunting idle, hesitation under light throttle, and occasional stalling. The condition is most pronounced when the engine is fully warm. The EGR valve is not equipped with a position sensor, meaning the control unit cannot detect incorrect positioning. Cleaning or replacement of the EGR valve resolves the condition.

How much does it cost to fix on a Mazda Mazda6?

$160 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 Mazda Mazda6 years are affected?

Our research records this fault on the 2007–2013 Mazda Mazda6. 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.