NW ECU Upgrade

[11T.Co]

Hi,
New user here and first post.

I finally bit the bullet and joined the ranks of 4WD owners with a new Pajero and after driving away from the 1500 km inspection I discovered a brand new "sound" coming from the engine.

The sound was predominant when accelerating and then slightly releasing the throttle to force the automatic transmission up a gear, occasionally it could also be heard under normal acceleration as the gear changed up.

It sounded like a cross between a slipping belt and a wheeze which I couldn't quite make out or associate with anything I knew; so I took the car back to the dealer today and the workshop foreman identified it as the turbo boost pressure relief.

During the 1500 km inspection they did a firmware upgrade on the ECU which fixes a turbo low boost issue with some vehicles. My vehicle must have been one of them and with the increased boost pressure the boost relief is doing its job, which is what I am now hearing.

Some members here may also have a low boost issue which they are not aware of, and knowing about the ECU upgrade may be helpful.

Cheers,

[mynance]

Mine does that as well, the NT didn't do it. I assumed it was similar to those blow off valve that people put in those small turbo cars.

Myles

[Dion]

I can hear the pressure relief valve on my NT quite often.

[NTX]

Im assuming it is the relief valve I can hear when I back off under load and Im driving in a built up area with the window down. There is a wind down whistle sound. Its very noticeable driving in the hills and taking the foot off going into a turn, the sound bounces back off embankments.

[spiderpig]

Its prob the wastegate on the turbo your hearing.

[MattyDucati]

Turbo compressure surge is what your hearing. Nothing to worry about on that engine

[Bigbaddave12]

I love the sound. How can we make it louder?

[Dude]

Funny this, I noticed a change in the sound of the turbo when the car had done around 10,000ks. Also noticed a kind of buffeting shudder at 1600 revs at 80ks/ph.

I asked about the wastegate and they said the variable vain turbo in the pajero dosent have one and uses an air recycling method instead.

bottom line line is that it is a feature and I must be making things up.

dude.

[MoreliaMatt]

I love the sound. How can we make it louder?

X2!!

[markpeh]

X2!!

Me too! I find in my manual the sound is more noticeable than my fathers auto...

[11T.Co]

Im assuming it is the relief valve I can hear when I back off under load and Im driving in a built up area with the window down. There is a wind down whistle sound. Its very noticeable driving in the hills and taking the foot off going into a turn, the sound bounces back off embankments.

That's what it was but I had never noticed it until the ECU was upgraded last Saturday. Mitsubishi Motors obviously recognised there was a problem with some vehicles as the ECU upgrade addressed a low boost issue but I can't help wonder how many people aren't even aware that the problem exist.

Hopefully that will be taken care of during their next service but for those who don't use a M.M. dealer there's a chance that they'll miss out on the upgrade and whatever real world benefit it brings.

[SuperYOOT]

Funny this, I noticed a change in the sound of the turbo when the car had done around 10,000ks. Also noticed a kind of buffeting shudder at 1600 revs at 80ks/ph.

I asked about the wastegate and they said the variable vain turbo in the pajero dosent have one and uses an air recycling method instead.

bottom line line is that it is a feature and I must be making things up.

dude.

All turbos have waste gates, or "blow-off valve" fitted by law for emissions. But essentially they are just plumbed back into the intake after the butterfly. The noise you hear is affectionately referred to as the turkey gobble. Its the sound of the already spinning turbine in the intake side of the turbo caveatting or turbulence with the injection of it's own compressed air.

Nothing to worry about and some cars are louder than others. My XR6 Turbo was quite loud when I had it, but I only hear the compression hiss of the intake on my Patrol, when I back off there is no noise.