Low oil pressure on Pajero

[Parmin]

My Mitsubishi Pajero is made in 1994, it has 3L V6 petrol engine.

Lately, I noticed that the oil pressure gauge rarely go above 20
kpa even when I drive hard. And it sometime goes below 10kpa then
the engine just stalled.

I serviced this car regularly, every 10 000 kms or 3 months
whichever cames first. At every service, the mechanic replaced the
engine oil.
So the chance of having expired oil is very small.

When the problem starts, the mechanic suggest for me to use high
detergent (diesel grade) oil, because maybe sludge builts inside
the engine, and the hi-det oil will help to scrub and remove the
sludge. Plus, I should change the oil pump which I did right away.


It has now been 2 months since I change the oil pump and use the
hi-det oil and the problem still persists. The oil pressure still
is below 20 kpa My engine sometimes stalled because of it in an
intersection and this worries me a lot.

Any input in this matter is appreciated.

Par.

[Noddy]

Post by Parmin
Any input in this matter is appreciated.

Have the oil pressure checked by a reliable mechanic, and/or change your oil
pressure sedning unit.

And find a new mechanic.

--
Regards,
Noddy.

[Parmin]

Post by Noddy
Have the oil pressure checked by a reliable mechanic, and/or
change your oil pressure sedning unit.

I am quite sure that the oil pressure gauge and the sender is
working fine, I have had it checked at the time I found the
problem.

When the engine stalls, I could see that the oil pressure goes
really low. Even if the gauge were faulty, the engine still
stalled.

Post by Noddy
And find a new mechanic.

I may have to.

Thanks for your input.

Par.

[Noddy]

Post by Parmin
When the engine stalls, I could see that the oil pressure goes
really low. Even if the gauge were faulty, the engine still
stalled.

Some vehicles have a failsafe cutout wired into the ignition system whereby
the engine will be shut down if the oil pressure falls below a set point.
I'm not sure if your Pajero has such a system, but it may explain your
engine cut out problem.

If you've replaced the oil pump and still have the same low pressure
readings, then I'd double check your guage & sender, or start looking for a
new engine.

--
Regards,
Noddy.

[Parmin]

Post by Noddy

Post by Parmin
When the engine stalls, I could see that the oil pressure goes
really low. Even if the gauge were faulty, the engine still
stalled.

Some vehicles have a failsafe cutout wired into the ignition
system whereby the engine will be shut down if the oil pressure
falls below a set point. I'm not sure if your Pajero has such a
system, but it may explain your engine cut out problem.

I somewhat guess that this is the problem

Post by Noddy
If you've replaced the oil pump and still have the same low
pressure readings, then I'd double check your guage & sender, or

I will this weekend.

Post by Noddy
start looking for a new engine.

:Þ I am broke !

Post by Noddy
--
Regards,
Noddy.

Par.

[D Walford]

Post by Parmin
My Mitsubishi Pajero is made in 1994, it has 3L V6 petrol engine.
Lately, I noticed that the oil pressure gauge rarely go above 20
kpa even when I drive hard. And it sometime goes below 10kpa then
the engine just stalled.
I serviced this car regularly, every 10 000 kms or 3 months
whichever cames first. At every service, the mechanic replaced the
engine oil.
So the chance of having expired oil is very small.
When the problem starts, the mechanic suggest for me to use high
detergent (diesel grade) oil, because maybe sludge builts inside
the engine, and the hi-det oil will help to scrub and remove the
sludge. Plus, I should change the oil pump which I did right away.
It has now been 2 months since I change the oil pump and use the
hi-det oil and the problem still persists. The oil pressure still
is below 20 kpa My engine sometimes stalled because of it in an
intersection and this worries me a lot.
Any input in this matter is appreciated.

First have the gauge tested.



Daryl

[Parmin]

Post by D Walford
First have the gauge tested.
Daryl

Done that.

Par.

[hippo]

First off, I agree with the previous responses.
Secondly, you may have 2 separate problems.
Our 91 3L Pajero had increasingly frequent poor idling & stall problems.
Much better after stepper motor replaced and now apparently cured
completely with cracked manifold fixed.
Just out of interest, how much oil do you use between changes? Cheers

[Parmin]

Post by hippo
First off, I agree with the previous responses.
Secondly, you may have 2 separate problems.
Our 91 3L Pajero had increasingly frequent poor idling & stall
problems. Much better after stepper motor replaced and now
apparently cured completely with cracked manifold fixed.
Just out of interest, how much oil do you use between changes?
Cheers

I agree that I may have faulty stepper motor for the idle.
However, as my previous post said, I observed that the oil pressure
goes down then the engine stall.

I believe we use about 4.5 litres of oil when we change it.
In between changes, there is no need to top up because the stick
gauge shows that the oil is full (I am not burning oil).

I had the head gasket replaced two years ago when using a chemical
sniffer on the radiator cap shows that the head gasket is on the
way to be breached. So the engione is in pretty much top shape for
a two years old reconditioned.

This is mind bogling.

Par.

[hippo]

Post by Parmin
I agree that I may have faulty stepper motor for the idle.
However, as my previous post said, I observed that the oil pressure
goes down then the engine stall.
I believe we use about 4.5 litres of oil when we change it.
In between changes, there is no need to top up because the stick
gauge shows that the oil is full (I am not burning oil).
I had the head gasket replaced two years ago when using a chemical
sniffer on the radiator cap shows that the head gasket is on the
way to be breached. So the engione is in pretty much top shape for
a two years old reconditioned.

So at least you know it's not drinking all the oil! Ours uses about
1.5L/5000km. Stepper motor prob gradually increased until idle not
possible with the air on and only intermittently at about 300 without air.
Oil pressure always got quite alarming once idle fell below 500.

Idle much better once stepper motor replaced although still not perfect (&
our boss still couldn't drive it without stalling - maybe we've just
adapted better ....) Badly cracked manifold recently fixed up and prob
reportedly fixed. Let you know when it finally gets back to the farm this
week. Cheers

[Patman]

Come over here:

http://www.pajeroclub.com.au/forum/

I am sure a few of the members could help. The 6G72 is not known for low oil
pressure - even on high mileage motors. They are known though for early
lifter failure and for snapping of the harmonic balancer bolt - causing
bucket loads of $$ worth of damage to the crank.

It sounds more like an idle problem - low idle causing low oil pressure and
stalling.


Pat

Post by Parmin
My Mitsubishi Pajero is made in 1994, it has 3L V6 petrol engine.
Lately, I noticed that the oil pressure gauge rarely go above 20
kpa even when I drive hard. And it sometime goes below 10kpa then
the engine just stalled.
I serviced this car regularly, every 10 000 kms or 3 months
whichever cames first. At every service, the mechanic replaced the
engine oil.
So the chance of having expired oil is very small.
When the problem starts, the mechanic suggest for me to use high
detergent (diesel grade) oil, because maybe sludge builts inside
the engine, and the hi-det oil will help to scrub and remove the
sludge. Plus, I should change the oil pump which I did right away.
It has now been 2 months since I change the oil pump and use the
hi-det oil and the problem still persists. The oil pressure still
is below 20 kpa My engine sometimes stalled because of it in an
intersection and this worries me a lot.
Any input in this matter is appreciated.
Par.

[Parmin]

"Patman" <***@oz.com.au> while reading the NewsGroups, found
courage and express out opinion in news:afZge.440$oi7.3309

Post by Patman
http://www.pajeroclub.com.au/forum/

Thanks for the link.. great source of info :)

Par.

[Me]

Firstly change the oil yourself to a different grade.
See if the oil pressure changes... I've had car that showed significant oil
pressure variations with different oils.
May be a cheaper first step than ripping out the oil pump.
These posts talk a bit about it:
http://www.pajeroclub.com.au/forum/forum_posts.asp?TID=7342&KW=oil
http://www.pajeroclub.com.au/forum/forum_posts.asp?TID=6964&KW=oil

Post by Parmin
My Mitsubishi Pajero is made in 1994, it has 3L V6 petrol engine.
Lately, I noticed that the oil pressure gauge rarely go above 20
kpa even when I drive hard. And it sometime goes below 10kpa then
the engine just stalled.
I serviced this car regularly, every 10 000 kms or 3 months
whichever cames first. At every service, the mechanic replaced the
engine oil.
So the chance of having expired oil is very small.
When the problem starts, the mechanic suggest for me to use high
detergent (diesel grade) oil, because maybe sludge builts inside
the engine, and the hi-det oil will help to scrub and remove the
sludge. Plus, I should change the oil pump which I did right away.
It has now been 2 months since I change the oil pump and use the
hi-det oil and the problem still persists. The oil pressure still
is below 20 kpa My engine sometimes stalled because of it in an
intersection and this worries me a lot.
Any input in this matter is appreciated.
Par.

[Jason James]

"Parmin" <***@hotmailspam.com> wrote in message news:***@203.26.24.228...


IME with engines that have bad oil-pressure problems,..the common
identifying feature they all had was:

OP was normal at start-up, but slowly dropped as the engine heated up and
would fluctuate wildly with engine revs,..meaning there was no 'headroom'
left or the pressure was so low the relief valve was inoperative. In all
cases I had lousey running clearances on the crankshaft rod-bearings.

If your OP stays the same whether cold or hot, I suggest you are looking at
something different ie gauge, sender, OP relief valve, pump sucking air
where it mounts onto the block or in the pick-up, partially blockd pick-up
screen....

Jason