MajorCommonEngine

Mitsubishi Pajero Sport: 6G72 3.0 V6 worn valve stem seals and guides - blue smoke after idling

6G72 3.0 V6 worn valve stem seals and guides - blue smoke after idling is a common engine fault on the Mitsubishi Pajero Sport on the 1998–2008 cars, and we rate it major. Putting it right costs $1,200 to $4,500 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 15 documented faults on the Mitsubishi Pajero Sport.

Vehicle: Mitsubishi Pajero Sport
Engine: 6G72
Years: 1998–2008
Fuel: petrol
System: Engine

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

All Mitsubishi Pajero Sport faults15 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 12-valve 6G72 3.0 V6 used in the Challenger, Pajero and Triton is notorious for hardened valve stem seals, usually made worse by worn valve guides. Oil runs down the valve stems when the engine idles or sits, and burns off as a puff of blue smoke on start-up or when pulling away after idling. Owners describe the seals as a common problem and a tough job on this engine. Left alone, oil use climbs and spark plugs foul; seals alone may not fix it if the guides are worn.

What you would notice

Puff of blue smoke on a cold start
Blue smoke when pulling away after a long idle
Oil level dropping between services
Oily, fouled spark plugs and rough running

How to check it

Where to look. Cylinder heads on both banks of the V6; smoke visible at the tailpipe

Ask for the engine to be cold when you arrive and have someone start it while you stand behind the car and watch the exhaust for a blue puff.
Later in the viewing let it idle for five minutes, then pull away briskly while a helper watches the exhaust.
Check the dipstick level and ask how much oil it uses between services.
Look at the tailpipe for heavy oily soot.
If a workshop inspection is possible: have a compression and leak-down test done to tell worn seals and guides apart from worn rings.

What it costs to put right

$1,200 to $4,500 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

“Does it smoke on start-up or after idling?”
“How much oil does it use between services?”
“Have the valve stem seals or heads ever been done?”

Now check the Mitsubishi Pajero Sport 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 the sources below. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them.

ProductReview.com.au Mitsubishi Challenger owner reviews ('stem valve seals' a common problem, smoking at idle)
BobIsTheOilGuy forum 'worn valve seals' (12-valve 3.0 6G72 notorious for bad valve seals)
4x4community.co.za forum thread 'Colt V6 Valve Stem Seals' (6G72)

Mitsubishi Pajero Sport buyer questions

Is 6g72 3.0 v6 worn valve stem seals and guides - blue smoke after idling serious on a Mitsubishi Pajero Sport?

We rate it major and common on the Mitsubishi Pajero Sport. The 12-valve 6G72 3.0 V6 used in the Challenger, Pajero and Triton is notorious for hardened valve stem seals, usually made worse by worn valve guides. Oil runs down the valve stems when the engine idles or sits, and burns off as a puff of blue smoke on start-up or when pulling away after idling. Owners describe the seals as a common problem and a tough job on this engine. Left alone, oil use climbs and spark plugs foul; seals alone may not fix it if the guides are worn.

How much does it cost to fix on a Mitsubishi Pajero Sport?

$1,200 to $4,500 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 Mitsubishi Pajero Sport years are affected?

Our research records this fault on the 1998–2008 Mitsubishi Pajero Sport. 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?

Ask for the engine to be cold when you arrive and have someone start it while you stand behind the car and watch the exhaust for a blue puff. Later in the viewing let it idle for five minutes, then pull away briskly while a helper watches the exhaust. Check the dipstick level and ask how much oil it uses between services. Look at the tailpipe for heavy oily soot. If a workshop inspection is possible: have a compression and leak-down test done to tell worn seals and guides apart from worn rings. Look here: Cylinder heads on both banks of the V6; smoke visible at the tailpipe