Broken Turbo

[bidds]

Installed a new map about 8 weeks ago. Has been going really well, however...

Today while dragging a 1100kg'ish trailer home from a camp, up a shallow incline at 110km/hr, the power died. Still ran fine but didn't have any grunt; no obvious problems. I pulled over and checked for faults on the NANOCOM: nothing on engine or gearbox.

Switched off and on, hoping for an over-boost reset. I had been watching the boost and temps via the NANOCOM (no apparent issues) so it was wishful thinking. No luck in any case.

Did some aulro searching: found wastegate solenoid bypass - tried that but no joy.

With the inlet air hose (MAF-turbo) off, I noticed the ends if the impellor seemed to have impacted the housing and the nut on the shaft was loose. It seems the turbine and compressor impellers are no longer connected. Feels like the turbine/exhaust side has seized.

Drove home at about 80km/hr, dropping to 55km/hr up the hills. Will pull it apart over the next few days and report.

Has anyone else had something similar? Any idea of a cause (could it be the map ? - it's a very reputable one with emphasis on reliability) or is it just one of those things?

Cheers,

Bidds

[Dougal]

How much boost was out running and how hot was the egt in a sustained load situation?

[bidds]

1.3 Bar is the max I've ever seen/recorded on the NANOCOM; I think the max yesterday was 1.28.

No idea about the EGT though - no EGT guage - idea of the conservative map was to avoid having to monitor it.

[Dougal]

1.3 Bar is the max I've ever seen/recorded on the NANOCOM; I think the max yesterday was 1.28.

No idea about the EGT though - no EGT guage - idea of the conservative map was to avoid having to monitor it.

The only conservative map which doesn't require EGT monitoring; is the factory map.

[twr7cx]

The only conservative map which doesn't require EGT monitoring; is the factory map.

Debatable, I'd still monitor the EGT.

[bidds]

What sort of temps do you see?

[twr7cx]

What sort of temps do you see?

Anything from 0*C before I start the car in winter to 700*C, after which I back off to keep them down.

[Disco Muppet]

Debatable, I'd still monitor the EGT.

Unless you're at max GCM locked in 3rd sport trying to hold 110 up a hill, you're not going to cook it on a stock map.

[Dougal]

Unless you're at max GCM locked in 3rd sport trying to hold 110 up a hill, you're not going to cook it on a stock map.

You'll see max temps in high gears, particularly when rpm drops and boost also drops. 4th (auto) will give higher EGT than 3rd.

It is a common and completely wrong misconception that high rpm is required to give high EGT.

[schuy1]

I have been told that high RPM will give a lower EGT reading due to the highish through flow of gases, has a sorta cooling effect like when the fan kicks in with a radiator. loaded, low RPM, more fuel burnt, slower though flow of gases, causes the EGT to rise. That is why going down in the gears will lower EGT with a load.
Sound feasible? Thats what I been told anyway and it makes sense to my mind as thats what happens with a non turbo.ed motor, let it labour in a high gear loaded and the temp gauge goes up.
Cheers Scott

[Dougal]

I have been told that high RPM will give a lower EGT reading due to the highish through flow of gases, has a sorta cooling effect like when the fan kicks in with a radiator. loaded, low RPM, more fuel burnt, slower though flow of gases, causes the EGT to rise. That is why going down in the gears will lower EGT with a load.
Sound feasible? Thats what I been told anyway and it makes sense to my mind as thats what happens with a non turbo.ed motor, let it labour in a high gear loaded and the temp gauge goes up.
Cheers Scott

Sort of.
The airflow through your engine tapers off as rpm rises, fuel delivery (stock) is also tapered off to match.
But with diesels the burn speed is fixed and so higher rpm usually gives a higher EGT reading as fuel is still burning later in the stroke. At higher rpm the combustion temps can drop but measured EGT rises. This is okay.

On turbo engines the worst point is when the turbo is still spooling up. This is when diesels normally run the richest A/F ratio and hottest EGT. If towing you can often end up driving for some time in this dangerous place. It is made far worse by aftermarket tunes where they use extra fuel to try and spin the turbo up sooner.

The main reason EGT drops when you go down a gear is the load and torque required from the engine drops. The second reason is getting it away from the point where you turbo hasn't quite spun up.

[twr7cx]

Unless you're at max GCM locked in 3rd sport trying to hold 110 up a hill, you're not going to cook it on a stock map.

If your so confident in the stock standard setup, supply a D2 and I will gladly demonstrate.

[Disco Muppet]

If your so confident in the stock standard setup, supply a D2 and I will gladly demonstrate.

How about you give me a theoretical run down ;)
Dougal, in my example I made a typo, meant to say 4th locked, i.e top gear. So the box would be labouring, under very high load from the engine, which is what you said :)
I'm aware that gearing down is what helps reduce EGTs.
So like I said, unless you're being really silly, I doubt you'll cook it on a stock tune, but that remains my humble and often uninformed opinion :)

[Dougal]

I wouldn't expect to be able to cook an as-new TD5 on a stock tune. But given ~15 years of sensor values drifting anything is now possible.

[bidds]

Which sensors are the ones that are most likely to influence this?

[bidds]

uestion:
Is there any value in putting a VNT into my truck (D2a) given I'm not going to mod the airbox, change the intercooler or remove the Mantec snorkel?

I'm in comms with BAS and td5inside and getting the impression that I might be best off just fixing or replacing the standard turbo.

I was planning to go with the S208-1 and a close-to or totally stock map. Jose' from td5inside is happy to do a map to suit.

Many thanks for facts, thoughts, opinions :)

[Disco Muppet]

If you tow alot, I'd go VNT + suitable map, Larger intercooler, extra trans cooler, and an EGT gauge.
That should give exceptional results.

[bidds]

How much larger should the intercooler be? Would the D2a version be considered usefully bigger?

[bidds]

Here's the compressor. Blades look very worn - stuffed bearing? The nut from the shaft was missing. Guessing that's in the intercooler somewhere.
https://www.aulro.com/afvb/images/imported/2014/03/341.jpg (https://www.flickr.com/photos/23750137@N07/13402312183/)

Here's one view of the turbine. Blades look bent, with some chunks missing. Guessing they're embedded in the centre muffler - is that a drama?
https://www.aulro.com/afvb/images/imported/2014/03/342.jpg (https://www.flickr.com/photos/23750137@N07/13402528234/)

Here's another of the turbine - I've rotated it a bit. Can more clearly see a large chunk missing.https://www.aulro.com/afvb/images/imported/2014/03/343.jpg (https://www.flickr.com/photos/23750137@N07/13402287703/)

Any ideas what this would cost (very roughly) to have fixed/reconditioned?

[bidds]

I was also getting symptoms of broken exhaust studs: occasional screech (actually, only once); 'turbo' whistle. On removing the turbo, I found nothing broken and only a nut missing at the very back of the mainfold and some evidence (soot) of a small leak next to it. I've loosened all exhaust manifold nuts and they've come off nicely.

Does this indicate that perhaps it wasn't excessive heat that killed the turbo? Just a worn bearing?

Would worn impellor blades mean poorer pumping ability and perhaps higher EGTs and coolant temps? I seem to recollect there being a reasonable amount of wear for a long time - looks to have much bigger gaps between the housing and impellor blades than images of new turbos.

[twr7cx]

uestion:
Is there any value in putting a VNT into my truck (D2a) given I'm not going to mod the airbox, change the intercooler or remove the Mantec snorkel?

I'm in comms with BAS and td5inside and getting the impression that I might be best off just fixing or replacing the standard turbo.

I was planning to go with the S208-1 and a close-to or totally stock map. Jose' from td5inside is happy to do a map to suit.

Many thanks for facts, thoughts, opinions :)

Depends on the price difference between the standard turbo (either through reconditioning your current one if suitable, a second hand replacement or a new replacement) and the VNT. If the prices are similar, definitely go the VNT. Even on a standard vehicle you'll get an improvement. BAS have previously confirmed that their VNT kit can be installed on a standard motor.

Also remembering that diesel motors run cooler when they're AFR's are lean. So the VNT may result in lower EGT.

[twr7cx]

How much larger should the intercooler be? Would the D2a version be considered usefully bigger?

The D2a intercooler is larger and superior to that of the D2. There's a few threads with pictures.

The aftermarket offerings are larger again.



I was also getting symptoms of broken exhaust studs: occasional screech (actually, only once); 'turbo' whistle. On removing the turbo, I found nothing broken and only a nut missing at the very back of the mainfold and some evidence (soot) of a small leak next to it. I've loosened all exhaust manifold nuts and they've come off nicely.

Does this indicate that perhaps it wasn't excessive heat that killed the turbo? Just a worn bearing?

Indicates a warped exhaust manifold.

[Dougal]

Which sensors are the ones that are most likely to influence this?

Airflow and MAP.


uestion:
Is there any value in putting a VNT into my truck (D2a) given I'm not going to mod the airbox, change the intercooler or remove the Mantec snorkel?

I'm in comms with BAS and td5inside and getting the impression that I might be best off just fixing or replacing the standard turbo.

I was planning to go with the S208-1 and a close-to or totally stock map. Jose' from td5inside is happy to do a map to suit.

Many thanks for facts, thoughts, opinions :)

I would go for a GT2056 over a VNT. It's a straight bolt-on. Compounding the original GT2052 turbo would be better than all the rest.

[td5inside]

How many miles was the turbo??

Garrett gives 80.000 kms of life expectancy :)

I have 2 td5´s @ home @ the moment! One of them broke the turbo with 100.000 kms the other one, had the turbo replaced @ 235.000 kms because the car seamed to be loosing a bit of power, but the turbo was not in total bad shape:)

There are alot of factors that can lead to turbo failure and the td5 has one that it´s a bit common...the pipe that feeds oil to the turbo is very near of the manifold so it gets a lot of heat. Sometimes there is restriction in that pipe, special on cold starts, so the turbo gets bad lubrification and gets worn a lot quicker.

Regarding turbo replacement, I am a big fan of the stock turbo. Good, reliable, an excellent compromise.

I´ve tunned a few turbo that were coupond to 2056 or more and did not like it. You loose a bit of down low power and get a bit in the higer revs, wich I dont think the td5 needs!

The S208 can also be a good option... I would take my option depending on price!

Regards,

[bidds]

That's good enough for me!

It's at about 135000km, so I guess it's done well in the scheme of things.

Would you recommend replacing or cleaning the oil lines to the turbo?

Thanks to all who've offered their thoughts, experience and opinions - much appreciated!

In the end I've decided to go with a new stock unit. My local LR guru says the part has been improved over the years and will give better performance than the original one. Combined with a mild td5inside map, I think I'll have a very good solution.

cheers,

bidds :)

[Dougal]

That's good enough for me!

It's at about 135000km, so I guess it's done well in the scheme of things.

Would you recommend replacing or cleaning the oil lines to the turbo?

Thanks to all who've offered their thoughts, experience and opinions - much appreciated!

In the end I've decided to go with a new stock unit. My local LR guru says the part has been improved over the years and will give better performance than the original one. Combined with a mild td5inside map, I think I'll have a very good solution.

cheers,

bidds :)

Still no mention of an egt gauge!