Vacuum Pump

[Rusty4]

I have a an occasional gringdng noise when slowing down and nearly stopped in a 2006 NP 3.8l auto.
Just before stopping there is a light "thump". A gearbox specialist tells me it the vacuum pump is going and the noise is the hub engaging and disengaging. He says many gearboxes have been pulled out and replaced and that was not the problem.

The part (vacuum pump) was only available from Mitsubishi but they no longer stock it before 2008 models.

Any help on where I can get one would be appreciated. I have called about 10 wreckers and no luck so far.

[Scooby]

Are you talking about a grinding noise in the front axle?
Are you driving in 2wd, try 4wd an see if the noise goes away.
I didn’t know the petrol 3.8 had a vacuum pump.

My NM was making grinding noises when slowing down , driving around town in 2wd.
It was the 4wd engaging in the front axle, I replaced the solenoids under the air cleaner and that fixed the problem, I think it was also due to driving steady.

The NM only has the 3.5 petrol engine and doesn’t run a vacuum pump, it just uses the engine intake for vacuum for the 4wd and the brakes.

[Rusty4]

Vacuum pump

I've been away on the NP thanks for your reply.

It sounds like the same problem as yours. Right front axle engaging on occasions when in 2H and only when slowing down and almost stopped. It disengages with a thump. A gearbox specialist tells mee he fixed quite a few over the years but not lately. He says its the vacuum pump. Mitsubishi say they they sell them before the 2008 model NP and they are not interchangeable with 2006 which mine is.
Over two weeks whilst I was away it did it about 6 times.
I'm also getting the yellow flashing light on the transfer case diag. It generally starts after 15 mins of travel in 2H.

[Having Fun]

We have a 3.8 NP too & have had exactly the same problem as you last year; I bought a new solenoid for under the air box on ebay for twenty something dollars, which took about 5 minutes to fit & the problem went away and hasn't come back.

[truK]

That’s the same symptoms as what we had - fix for us was also to fit a new vacuum solenoid unit.

Maybe give that a shot before committing to a new vacuum pump

[disco stu]

Just to note here-being a petrol motor you won't have a vacuum pump, it just works off engine vacuum in intake manifold

[raysosher]

Brakes check

Did you check all your brakes?, are they fine?, also give a suspension check as well. These type of noise normally does not appears from engine. Check up the entire suspension system and see if there are any loose ends.