HELP! 3B turbo (GT2052) running on oil at 2000kms old (1 Viewer)

[brisveganbj42]

Hi guys,

Its been a while since I've posted in here but things have got serious and I need some expert advice... I have done a bit of digging around for any potential failures of 3b turbos but didnt turn up anything relevant to my issues..

Firstly a bit of history.

About 2000kms ago I slapped a brand new GT2052s on my 3B that had about 320,00kms on it. I set the boost to 11psi max and had a pyro installed post-turbo maxing via throttle out at 550deg celcius. Oil feed was sourced from the oil pressure sender, and return line fed to the sump.

There was no oil restrictor added tot he oil feed (and talking to turbo manufacturer, its not required for the bearing type in this turbo).

Most recently I was driving along some suburban streets maxing out at about 60kph when my 3b started to run on at high RPM's. I was able to pull into a side street where I turned the car off but the engine kept running. Both hoses going into each side of the throttle butterfly appeared to be intact so I attempted to starve the engine of air via the flexible hose from the snorkle but wasnt able to completely starve it due to air coming in via the water drain of the airbox.

Next I took off the intake pipe and starved the engine of air at that point to shut it down. After getting it towed home I removed the turbo and found oil on the intake.

From airbox to intake..
- turbo intake hose is kinked due to it collapsing when trying to starve of air.

silicon reducer onto the turbo intake

little bit of oil on the turbo intake..

Hope its a genuine garret

I'd already cleaned up the inside of the intake

other bits
oil supply and adapter

oil return

I checked I could run oil down the turbo return line after installing the turbo and I checked the air filter for restrictions (it didn't appear to be any).

I returned the turbo to the manufacturer to tear down and inspect who found nothing wrong with the turbo with everything within spec.

Report can be found here http://www.phat42.com/files/turbo_failure_report.pdf

Upon collection of the rebuilt turbo it was suggested that I'd lost compression on my engine causing presurisation of the sump and forcing oil back up the return line and past the seals into the intake as being the likely cause.

To rule that out I've done a cold compression test (without the throttle wide open though) with the following readings:
1: 415
2: 350
3: 380
4: 400

Doing a wet the figures are pretty similar:

1: 440
2: 350
3: 360
4: 380

Dont know if the results are lower with my battery getting tired...

Before the battery died after doing the compression tests I reconnected the edic and tried to fire it up (with glow plugs in) and it roared to life with full revs again so I quickly shut it down. I would of thought any oil in the cylinders from when the turbo fed oil into the intake would of gone down past the rings as its sat for over a month. I wonder if its drawn oil from the intake manifold into the cylinders as I turned off the engine and it continued to run.

Having a think about this tonight.. If the governer diaphram didnt get a tiny tear but a complete tear and separated, would it show similar behaviour?

Some thoughts I had are:

1) what if it was something else causing the engine to run on and by creating a vacuum via the snorkle hose and not being able to completely starve it of air, would that then force oil past the seal in the turbo into the intake?

2) are the variance in those compression figures OK? Does it matter the compression test wasnt done with wide open throttle?

3) I have a factory paper air filter, if this was a bit clogged (I had competed in dusty conditions approximately 2weeks prior to this failure) would it create enough of a vacuum to suck oil past the bearing in the turbo and then into the intake? Would a free-er flowing air filter be better eg: K&N?

4) Would the hose from the airbox to the turbo be a potential issue? Its wire ribbed and fairly stiff.. also the hose from the snorkel is fairly stiff as so I dont believe this would collapse, and it didnt appear to be that way before trying to starve the engine of air.

5) in regards to point above (#4) would a fixed welded pipe be better than the hose that's there at the moment?

6) Would I need to adjust valves to improve compression figures? Is it worth doing the valve seats too (and precups while the head is off), again to improve compression. is this completely necessary or a nice to have as I'm on a tight budget as it is.

7) I'm going to inspect the diaphragm governor to ensure that's not causing issues but has anyone had issues where its completely separated instead of a tear? I've had a tear in mine before and its idled quite high (double stock idle rpm?)

I've removed the oil feed from the oil pressure sender so I can operate and fire up the engine to ensure its idling fine and no other damage was done.

So yeh, thats where I'm at... Any help and tips are greatly appreciated.. I'm missing driving my 40 around and its looking pretty sad in the shed so any tips or comments that'll help it get out and on the road again would be great!

Thanks,

Andrew

 

[brownbear]

Ive heard of carbon seal failures on turbos causing engine runaway. Basically it is running on it's own oil supplied by the turbo. Worst part is it is ungoverned. SO you could potentially over rev the engine to catastrophic failure. Depends on the leak size.

Some oil in the intake is normal. I rebuilt my turbo and after 1000 kms I saw some oil. I ignore it.

Next step is a new diaphragm for sure. Don't inspect. Just replace. Its not worth the hassle to inspect. If you're in there you might as well just put in a new one.

 

[cody c]

Did you check the two clear lines on the side of the intake manifold?, if one of those cracks it will start to rev wildly. The lines weren't meant for turbo pressures or hotter gasses, it happened to me after about a month of driving.

You may be getting oil blowing past the bearings, doesn't mean the turbo's toast, but you could benefit from a restrictor. Ian G (iggi on ih8mud) has the same oil/bearing/turbo thing going on and he's just been driving it like that.

If your truck wouldn't shut down, did you check your edic motor is working, you should see it change position when you turn on the ignition.

 

[brisveganbj42]

Next step is a new diaphragm for sure. Don't inspect. Just replace. Its not worth the hassle to inspect. If you're in there you might as well just put in a new one.

I've got a replacement here so that will be going in. As you say if you're in there might as well put a new one in for the $30 they cost.

Did you check the two clear lines on the side of the intake manifold?, if one of those cracks it will start to rev wildly. The lines weren't meant for turbo pressures or hotter gasses, it happened to me after about a month of driving.

You may be getting oil blowing past the bearings, doesn't mean the turbo's toast, but you could benefit from a restrictor. Ian G (iggi on ih8mud) has the same oil/bearing/turbo thing going on and he's just been driving it like that.

If your truck wouldn't shut down, did you check your edic motor is working, you should see it change position when you turn on the ignition.

Edic is fine, has worked well and it moves when turning on/off.

Wondering if a restrictor is due to the oil pressure (which is within normal limits as per the stock gauge). Talking to MTQ they reckon its not necessary and wouldn't this potentially lead to oil starvation? I would of thought if oil pressure was too much it would of become apparent earlier than this.

I'll check the clear lines and ensure they are in good condition. If they were cracked, wouldn't turning off the engine shut it down and not cause it to run on? Would they create a vacuum sucking oil past the seal in the turbo?

Sorry to answer more questions with questions but want to get my head around as much as possible.

 

[cody c]

Its been probably 8 or more years since I had the issue with the line so my memory is fuzzy. It acted like a runaway engine but I cant remember if I stalled it with the pedal or simply shut the engine off, but it did act like a runaway diesel when that line burst.

As for oil pressure, Id suggest getting an aftermarket gauge, Ian has oil all over the place and through his intake and he doesnt have a restrictor. Same thing as yours, and we replaced his bearings before we installed it!

The oil pressure is only high when your heavy on the throttle or it is cold and slow moving in the morning. I think it runs to around 80 psi at heavy throttle though, and this may exceed what a gas engine provides, or its possible the original line was smaller and acted as a restriction. I believe Ryan B (Lucky13 on IH8mud) had the same issues and fixed it by restricting flow with an orifice or regulator.

I would suggest checking the bearings on it if your worried, and add an orifice (restriction). If your worried about starving it for oil then you can mount a pressure gauge after the restriction, but I'm willing to bet that is the issue.

 

[Dougal]

First up. Any-time you try to stop an engine with a vacuum it will pull oil through the turbo intake seals.
These turbos do not run carbon face seals. They run labyrinth and a vacuum in the intake or too much pressure in the drain will make them spit oil.

So just because there is oil in the intake, doesn't always mean it was there before you started to choke it.

What you need to do is remove the turbo and see if you can re-create the problem without it. Like the turbo guys I'll bet you have another problem which is causing the initial run-away and possibly made to continue once the sump has pressurised enough to make the turbo spit oil.

Interestingly I've never had my engine run on for more than a few seconds and I've had some serious oil issues in the past.

Step 1.
Remove the turbo, go for a drive without and measure crankcase pressure under load.

 

[brisveganbj42]

Thanks Guys,

Dougal, thats where i'm at at the moment. After doing the compression test I expected it to run normally but it ran on without the turbo mounted as well.. So I'll continue to troubleshoot until I can get the engine running normally in the shed. Not sure if I have an exhaust manifold allowing me to take it for a drive around the streets once it appears to run normally.

How do you measure crankcase pressure under load?

 

[cody c]

First up. Any-time you try to stop an engine with a vacuum it will pull oil through the turbo intake seals.
These turbos do not run carbon face seals. They run labyrinth and a vacuum in the intake or too much pressure in the drain will make them spit oil.

So just because there is oil in the intake, doesn't always mean it was there before you started to choke it.

.

Dougal, can you verify, If the edic is working properly how can this continue to run, I've heard this is the case in a 3B running backwards (stalled on a hill, then push started as it rolled backwards) but don't understand the logistics of why the edic would not shut the engine off.

I can see how the turbo would want to suck oil through the bearings, but 'Im skeptical it would in the second or two it takes to stall the engine from blocking off the intake, and have to be in conjunction with high oil pressure I would think. Perhaps we should have an engine kill butterfly valve installed on our rigs vs. the edic, or a fuel valve near the IP for a runaway.

 

[Dougal]

How do you measure crankcase pressure under load?

Take out the dipstick, clamp a line over it and route to a sensitive pressure guage in the cab.

If it registers anything when driving, then you have breather issues to sort out. At least your good compression rules out excessive blowby.

Dougal, can you verify, If the edic is working properly how can this continue to run, I've heard this is the case in a 3B running backwards (stalled on a hill, then push started as it rolled backwards) but don't understand the logistics of why the edic would not shut the engine off.

Sorry I don't know the finer points of 3B shut-off. But unless airflow is shut-off completely, it has the potential to run.

I can see how the turbo would want to suck oil through the bearings, but 'Im skeptical it would in the second or two it takes to stall the engine from blocking off the intake, and have to be in conjunction with high oil pressure I would think. Perhaps we should have an engine kill butterfly valve installed on our rigs vs. the edic, or a fuel valve near the IP for a runaway.

There is always oil right up to the inside of the labyrinth seals. Reverse the pressure across the seal and it'll come out pretty quick.

After the crank-case pressure and breathers, oil supply pressure is the next thing to check.

 

[brisveganbj42]

So I got the governor diaphragm out tonight to inspect.. It didnt appear to be connected to the rod in the injector pump.. what effect would this have if the 8mm nut came off while driving? Is there supposed to be an R clip in there too? I'm going to review the FSM but haven't as of yet..

 

[cody c]

Take out the dipstick, clamp a line over it and route to a sensitive pressure guage in the cab.

If it registers anything when driving, then you have breather issues to sort out. At least your good compression rules out excessive blowby.


Sorry I don't know the finer points of 3B shut-off. But unless airflow is shut-off completely, it has the potential to run.

.

My understanding is the EDIC adjusts fuel during warm up or something, and is fuel shut off to kill the engine. If he couldn't shut the engine off by key, then it would be my assumption that the EDIC wasnt working, though maybe the linkage to the governer diaphram effects it.

Replace that diaphram, I had mine go in my 60 before and it caused the truck to blow white smoke all the time, not sure exactly how that thing works but it is important.

 

[Dougal]

So I got the governor diaphragm out tonight to inspect.. It didnt appear to be connected to the rod in the injector pump.. what effect would this have if the 8mm nut came off while driving? Is there supposed to be an R clip in there too? I'm going to review the FSM but haven't as of yet..

That could be all of your problem right there.

 

[brisveganbj42]

That could be all of your problem right there.

I think it might be. I fished out the bracket and 8mm nut with a magnet and put it a new diaphragm with spring washer, washer and cotter pin and put it all back together.

The rod the diaphragm connected to was all the way towards the front of the pump..

I crossed my fingers and started the 40 after replacing it all to have it idle nicely at 650RPM. so I'm hoping that's it. Im going to run it a bit more before putting the turbo back on over the weekend.

So it looks like I caused the oil to go past the turbo seals by trying to starve it of air...

 

[brisveganbj42]

Thanks for everyones input.. I got the turbo back on and took it for a test drive today without issues... got a few things I want to sort but I'll post up in other threads.

 

[brownbear]

Its been probably 8 or more years since I had the issue with the line so my memory is fuzzy. It acted like a runaway engine but I cant remember if I stalled it with the pedal or simply shut the engine off, but it did act like a runaway diesel when that line burst.

I had one of my clear lines pop off after putting on a turbo. Was quite the experience. Uncontrolled rpm. Sat around 3500-4000 rpm till I hooked up the line. Luckily it never broke, just popped off.