2003 GU Patrol 3L Losing Power

Hi,

I have a 2003 GU Patrol 3L Diesel,
About a week ago when I was driving, I turned a corner and accelerated off,
When I was in 4th or 5th gear and was at about 2500 RPM, it seemed to lose pulling power.

I put the clutch in and revved it a bit and it seemed fine, I drove around for a while and all seemed good, but then it happened again.
I didn't notice it again for about another week, when it happened while just accelerating up a road.
I haven't noticed it since.

On all cases I wasn't accelerating hard.

My Patrol has a Dawes valve set to 15 PSI.
The engine was reconditioned about a year and a half ago and had a new fuel pump installed.

Does any one have any idea what could cause this?

Thanks,

Lucas

How much fuel was in the tank at the time?

It's sounds it could be going into limp mode. With your Dawes valve set to 15 psi it could have just slipped over into lump mode. Did any lights on the dash board come on or not

Any change in fuel economy?

Might sound like a silly question but was it a particularly cold day. Mine sometimes goes into limp mode on a cold morning. Only ever happens once then is ok for the feast of the day.


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4bye4 I'm with you on this mine has done the same thing a few times. Especially with the Dawes set so close to the limp mode threshold could have slipped over setting it off.

you could have a leaking intercooler ,,,is it oily if yes and will need to be changed to
fully tigged and tested Diesel smart one ,, dont go cross country for your
3ltr just a waste of money IMO, Money could be well spent elsewhere like a front lokker maybe

I know every truck is different regarding limp threshold, but I would have thought 15psi on the Dawes is comfortably under limp. But I have to admit it does sound like it.
Maybe start with the easy stuff and bring your Dawes setting down a bit more as an experiment.
Perhaps the MAF sensor could do with a spray clean?

Quote:

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Originally Posted by Softy

How much fuel was in the tank at the time?

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There was plenty of fuel in the car every time it happened.

I replaced the air filter today and found that the old was really dirty,
I went for a 5 hr drive tonight and it is definitely still happening.

I was pulling a small trailer with nothing in it and it usually drove fine, but sometimes it decided that it wasn't going to go faster than 90 and the exhaust temp started to go up.
I didn't let it get over 400 degrees.

Quote:

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Originally Posted by 4bye4

Might sound like a silly question but was it a particularly cold day. Mine sometimes goes into limp mode on a cold morning. Only ever happens once then is ok for the feast of the day.


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No it wasn't any colder than usual, i have only noticed it after i have been driving for more than 20 min.

Quote:

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Originally Posted by Daveyboyjunior

I know every truck is different regarding limp threshold, but I would have thought 15psi on the Dawes is comfortably under limp. But I have to admit it does sound like it.
Maybe start with the easy stuff and bring your Dawes setting down a bit more as an experiment.
Perhaps the MAF sensor could do with a spray clean?

---

I have no idea how to adjust the Dawes, just adjust the screw on top?
My mechanic said that it may be the MAF, he is going to have a look and give it a bit of a clean.
He said he will hook up a scanner and see if there are any errors.

Quote:

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Originally Posted by threedogs

you could have a leakying intercooler ,,,is it oily if yes and will need to be changed to
fully tigged and testetd one Diesel smart to a good 0ne dont go cross country for you
3ltr just a waste of monet IMO, Money could be well spent elsewhere like a front lokker maybe

---

There is a bit of oil down the side of the engine, around the turbo. I think its coming from the oil switch.
The mechanic replaced the switch recently so i'm gonna get him to see whats happening there.

There also seems to be a bit of oil coming out of the catch can hoses.
I'm not really sure if or how that could affect the engine.

I don't see any oil or leaks from the intercooler, but i will definitely get the mechanic to have a look.

Quote:

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Originally Posted by JackCollo

It's sounds it could be going into limp mode. With your Dawes valve set to 15 psi it could have just slipped over into lump mode. Did any lights on the dash board come on or not

Any change in fuel economy?

---

What is limp mode? Does it signify something bad?
No lights on the dash at all.

Quote:

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Originally Posted by lmath56

There was plenty of fuel in the car every time it happened.

I replaced the air filter today and found that the old was really dirty,
I went for a 5 hr drive tonight and it is definitely still happening.

I was pulling a small trailer with nothing in it and it usually drove fine, but sometimes it decided that it wasn't going to go faster than 90 and the exhaust temp started to go up.
I didn't let it get over 400 degrees.

---

what temp did it go from and to. how quickly did it go up?
so the temp shot up when it lost power??
starting to sound like a dirty MAF duck down to supercheap grab a can of mass airflow sensor cleaner. pull the maff off and the pipe that goes from the top of the airbox that the maf is apart of and give a darn good spray down from as many angle.
cheers

Quote:

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Originally Posted by lmath56

What is limp mode? Does it signify something bad?
No lights on the dash at all.

---

Alright so basically on your intercooler you have a pressure sensor which is set to 16psi so when the turbo spools up and creates pressure if it goes past 16psi it limits power which explains the sudden power loss. and the way to take the ecm out of limp mode you realease throttle and engage it again.

it wont set off any lights
So in summary limp mode is designed to stop the engine doing damage to itself in the form of over pressuring and blowing gaskets and such other. Ive noticed a lot of the earlier patrol if people keep their foot on the accelerator in limp mode the temps do go up but then drop after throttle released. temps go up due to slight over fueling

Quote:

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Originally Posted by JackCollo

what temp did it go from and to. how quickly did it go up?
so the temp shot up when it lost power??
starting to sound like a dirty MAF duck down to supercheap grab a can of mass airflow sensor cleaner. pull the maff off and the pipe that goes from the top of the airbox that the maf is apart of and give a darn good spray down from as many angle.
cheers

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It didn't go up too fast, I didn't strain it.
I got it to about 400 Max.
Yes when it lost power it seemed to get a bit warmer than usual.

I will definitely give the MAF a clean

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Quote:

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Originally Posted by JackCollo

Alright so basically on your intercooler you have a pressure sensor which is set to 16psi so when the turbo spools up and creates pressure if it goes past 16psi it limits power which explains the sudden power loss. and the way to take the ecm out of limp mode you realease throttle and engage it again.

it wont set off any lights
So in summary limp mode is designed to stop the engine doing damage to itself in the form of over pressuring and blowing gaskets and such other. Ive noticed a lot of the earlier patrol if people keep their foot on the accelerator in limp mode the temps do go up but then drop after throttle released. temps go up due to slight over fueling

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Ah ok, so the Dawes setting may have changed a bit and it needs to be adjusted back to 15.

I will change that and see what happens.



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Give the maf a clean and adjust your Dawes setting and you should be sweet

Disconnect the battery then service the MAF sensor with spray from Super cheap Auto.
re fit the MAF when its dry reconnect the start battery and see how you go.
You can test the IC by first removing it tape up the ends with duct tape use a bike
pipe and dip in a kiddies pool, Clean the inside with kero make sure its dry [hair dryer]
before reinstalling

On a total side note thank you threedogs for answering a question I had on how to clean intercooler. I was gonna use diesel? Is this a bad idea to use diesel only thought it would be good because if any is left over it will get burnt anyway but was told by someone else to use petrol which I know is an even worse idea.

I always use brake cleaner.
Swill that around for a bit and do that a couple of times.
Dries, evaporates a lot quicker, but as TD said....anything you use has to be totally bone dry before putting the IC back on.

Alright sounds pretty straight forward. What should I use to clean out intake manifold? All the carbon build up?

Carbie cleaner should do the trick, make sure all components are dry
before re-assembly

Quote:

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Originally Posted by lmath56

Hi,

I have a 2003 GU Patrol 3L Diesel,
About a week ago when I was driving, I turned a corner and accelerated off,
When I was in 4th or 5th gear and was at about 2500 RPM, it seemed to lose pulling power.

I put the clutch in and revved it a bit and it seemed fine, I drove around for a while and all seemed good, but then it happened again.
I didn't notice it again for about another week, when it happened while just accelerating up a road.
I haven't noticed it since.

On all cases I wasn't accelerating hard.

My Patrol has a Dawes valve set to 15 PSI.
The engine was reconditioned about a year and a half ago and had a new fuel pump installed.

Does any one have any idea what could cause this?

Thanks,

Lucas

---

The mechanic looked at the car today and found that the MAF was quite dusty, so he gave that a clean.
The fuel filter had quite a bit of water in the separator so he replaced that.
One of the hoses near the turbo was leaking a bit of oil. It was pushed back on and tightened,

He took it for a drive and it seemed fine, and i did as well. It seems to start a bit faster and have slightly more power now.

I will need to tow a trailer full of tiles and concrete in the coming days so that will really test whether this fixes the issue or not.

I will update if there are any further issues,

Thanks everyone for your help!!
This is the first time I have used this forum, and I will definitely be back!

Lucas

Make sure you do Lucas...we'll want to know how you get on.

Quote:

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Originally Posted by lmath56

It didn't go up too fast, I didn't strain it.
I got it to about 400 Max.
Yes when it lost power it seemed to get a bit warmer than usual.

I will definitely give the MAF a clean

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Disconnect the battery when you clean the MAF
will re-set the ECU, Check vacume hoses for cracks etc
make sure they are in good nick

Also if you're going to be towing bricks and concrete tiles
have a good look at strengthening the rear shock towers
they will crack

Glad to know we could help you Lucas please let us know how you go with everything after you test it and what not.

Good luck

Just to add another aspect to this conversation, last night it was a bit cool and I was in a 100kph area. As I accelerated I could see the guage go up to the 15psi then over to 16psi. If I continued at this it then went to limp. Normally my dawes is set to 15psi max and I only get 16psi in cold weather. This morning the max at 15psi is back to normal. So here is the theory. I think that the spring tension in the dawes changes just a smidge when it is cold and allows the setting to drift to over 16psi, which is where the limp mode kicks in. When the motor heats up or on a warm day the spring maintains its set point and all is good. Any other thoughts on this?

Hi there,
On your gauge, you may see a little bounce over your set limit.
To make your Dawes a little more responsive some guys (me included) just pop the spring out and stretch it just very slightly, and this added tension within the chamber should help the Dawes stay on your chosen limit.
Just my thoughts...
We don't have big temp differences over here unless it's freak weather.
Look at my post count... I've scored a century who hoo.
Gonna thank you for that 4bye4!

Quote:

---

Originally Posted by Daveyboyjunior

Hi there,
On your gauge, you may see a little bounce over your set limit.
To make your Dawes a little more responsive some guys (me included) just pop the spring out and stretch it just very slightly, and this added tension within the chamber should help the Dawes stay on your chosen limit.
Just my thoughts...
We don't have big temp differences over here unless it's freak weather.
Look at my post count... I've scored a century who hoo.
Gonna thank you for that 4bye4!

---

Sorrite mate.


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It's back!!
I was driving and it lost power again. I know how to replicate the issue too.
Once I put it into 5th, floor it and when it gets to about 90 it just stops accelerating and holds its speed. Stays at 11psi. No lights on the dash. It just sounds fine, like I am trying to hold speed at 90.
If I let go of the throttle and put it back on it just goes back to normal.
I couldn't replicate it going up or down a hill, I'm not sure if that's coincidence though. Going up or down it just accelerated through normally.
What do you reckon?


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