Sad day......Audi TT -> TDI "ran away"..........

[Shenandoah]

Folks,

I was driving up to the store in my Audi TT -> TDI and passed a car while in third gear going about 50 mph. Heard a loud "POP" then lots of smoke behind the car. Let off the accelerator but the car was still motoring along at 50 mph or so. Was on a two lane road near home with very few places to get a car off the road. Smoke changed to dark gray and thick. Was able to pull over and stall the car. It was really starting to clatter when I stalled it. Checked the dipstick and there was the tiniest bit of oil registering. Called a local towing company and had it towed home.

From the time I heard the "POP" to when I pulled over was 6/10ths of a mile.

I'm guessing the turbo failed and it pumped most/all of the oil from the engine into the intake. I have taken anything apart yet. I'll probably start with the valve cover. Then see how much oil is in the intercooler. Then check the turbo. Then keep going from there. I'll get it back on the road eventually...........

Eric

 

[BobnOH]

If it did not reach high RPMs, like above red line, you may be O.K. Tough engines.
You do need to repair the whatever (turbo likely +?). May be a good idea to remove the valve cover and inspect for damage.

 

[Vince Waldon]

One way to approach this is to drain the intercooler and then a quick compression test, looking for bent rods. If the bottom end is fine you carry on with the rest of the diagnosis, but if you find a bent rod or two you now know you're into a full bottom end rebuild on top of everything else (including turbo, if the intercooler is full), and can do the math of "fix what you have" vs. "put that time and effort into a yard engine"... which can come with its own turbo etc etc.

 

[ghohouston]

Your turbo is gone. I literally had the same happen last week. You'll need to remove the charge air cooler and all piping. Clean THOROUGHLY or buy another charge cooler. When the intake manifold and exhaust manifold are off of the engine, you can feel around for any pieces of metal. You'll need to clean the intake manifold out as well. Pull glow plugs and turn engine over with a ratchet not the starter. Go a couple of revolutions. I got mine shut down pretty quick, probably didn't get over 3,500 rpm's. Put another turbo on after cleaning everything up good and it's running fine. There may be metal lodged in the rubber piping too, so go over it with a fine toothed comb.

 

[csstevej]

Sorry to hear about it.
If you’re lucky the turbo shaft snapped and dumped oil into the exhaust…..this happened to me twice on two different cars. No bent rods…. Minimal oil in intake track, and nothing in the cylinders when I pulled gp’s and spun motor with the starter.

 

[Shenandoah]

Folks,

Pulled the intake and turbo off this morning. Looks like the shaft on the on the turbo sheared. Disconnected the piping to the intercooler and about 1 1/2 quarts of oil poured out. Going to pick up a compression tester and will see what compression looks like. Also have to figure a way to keep the turbo oil line from pumping oil out while testing the compression.

Trying to remember how to post pictures. Will add some once I figure that out....

Eric

 

[Shenandoah]

Let's see if the pictures post:

This is a Garrett VNT17 that I installed when I did the ALH swap in the Audi TT in 2017. Turbo has about 110,000 miles on it.

Oil running out of the turbo, exhaust side

Looking in to the turbo where the spool/wheel is. Broken/sheared shaft laying in there

Another picture looking in to the turbo

Eric

 

[csstevej]

DAMN !

 

[jmodge]

Ouch, with all the TDI’s you have listed I suspect you will have it all under control. Bummer though

 

[Shenandoah]

Folks,

More information: About 1 1/2 quarts of oil came out of the intercooler when I removed the lower hose. Drained what was in the oil pan and about 2 quarts came out, more than I thought was still in the engine. Sprayed the glow plugs with PB blaster then headed to Harbor Freight to pick up a diesel compression tester.

Got back home and loosened the hardlines to the injectors so I had more room to remove the glow plugs. Got them all out (yea!). Disconnected the plug to the injector pump and the wire to #3 injector. Put a new oil filter in and filled the engine with Rotella T6. Put the bad turbo back on and connected the oil line to it and the return oil line to the block. Put a towel over the engine and cranked it over 10 times. Lots of oil blew out of the glow plug holes. Did that 5 more times.

Put the compression tester nipple in glow plug #1. Cranked it 8 times. Did the same for #2 - #4. I've got the following for compression:

#1 - 510
#2 - 500
#3 - 500
#4 - 500

The numbers look good and I'm guessing there is some residual oil in the cylinders. Very happy with the numbers considering this engine has about 290k on it.

I may have gotten very lucky and destroyed only the turbo.

Next step is to order a new VNT17 and gaskets, maybe a new set of glow plugs and a new intercooler(?).

I'll post more once everything is back together.

Eric

 

[03TDICommuter]

#1 - 510
#2 - 500
#3 - 500
#4 - 500

excellent news!

 

[Vince Waldon]

Yup, some lemonaid out of the lemons for sure... go buy a lottery ticket!?!?

110 psi compression, after a similar snapped turbo shaft and run-away:

 

[KLXD]

Would've been wise to spin the motor without the plugs before measuring but I doubt the numbers would've been that close with oil in the cylinders.

 

[drew5250]

As someone new(ish) to the TDI world...how common is this issue? I have a hybrid VNT-17/15 on order from Xman Turbos, so I should be ok for a while. As someone that currently owns four turbo-diesel powered vehicles, I've never heard of a turbo shaft sheering like that.

 

[csstevej]

Yeah you dodged a bullet there……as suggested…. Go buy a lottery ticket.
Glad to hear that it wasn’t catastrophic.

 

[Shenandoah]

Vince,

Wow.....That is a bent rod. The rpms never really got that high after I heard the "POP", maybe around 3500. I know when I put the clutch in the engine raced, so I let the clutch back out trying to keep it from racing away. Was looking at your signature, you've got a 2005 BEW wagon also. That is the high mileage champ of my TDI collection: 442k.

KLXD,

After I removed the glow plugs, disconnected the electrical from the injector pump and had the hardlines off the injectors, I put a towel over the engine and turned it over 10 or so rotations, blowing a bunch of oil out the glow plug holes. I did that five time or so before doing the compression test.

I've got a turbo ordered and will clean/flush the intercooler as the one for the Audi is expensive. It is just a little narrower in width from the ones on the VWs.

Eric

 

[Judson]

I find it really really odd that after only 110k miles you blew a vnt17. Either that’s an outlier or something else is going on with the motor that overspinned the turbo.
???
I also went through two vnt17s, overspinned both due to a bad (and new) n75. I went with a gtd1752 after replacing the n75 and haven’t had a problem since.
Not enough data to draw a conclusion of course, but maybe there were some bad batches for a few years.

 

[jimbote]

I find it really really odd that after only 110k miles you blew a vnt17. Either that’s an outlier or something else is going on with the motor that overspinned the turbo.
???
I also went through two vnt17s, overspinned both due to a bad (and new) n75. I went with a gtd1752 after replacing the n75 and haven’t had a problem since.
Not enough data to draw a conclusion of course, but maybe there were some bad batches for a few years.

I went through two vnt17s, one was new and chucked a turbine blade with less than 50k the other was fairly low mileage and did the same thing. Also picked up a broken 17/22 that had the exact same damage. Seen others online as well that have broken turbine blades. Hopefully Garrett has solved that issue.

 

[ghohouston]

And on mine I had about a gallon of oil in the cooler.

As someone new(ish) to the TDI world...how common is this issue? I have a hybrid VNT-17/15 on order from Xman Turbos, so I should be ok for a while. As someone that currently owns four turbo-diesel powered vehicles, I've never heard of a turbo shaft sheering like that.

It's a luck of the draw thing. Being a responsible turbo diesel owner plays a big part in it. Don't pull right off the highway, or any road really and immediately shut the engine off. Let it idle at least a minute or so. Turbos spin a whole lot of rpm's, and when you shut the engine down, the turbo still spins for a few seconds, but you've just cut off it's oil supply. Heat is also another reason to not immediately shut down after driving hard. Keeping up with oil changes also plays a role, as turbo's use journal bearings in factory form. Lastly, poor tuning can cause overboosting which is hard on them.

 

[ghohouston]

20230525_221337.jpg

• ghohouston
• May 26, 2023

Here's mine. Been driving turbo diesels for 14 years and this is the first one that failed on me.

 

[burpod]

i really don't it's anything to do with "bad batch of turbos". i've seen way too many boost/etc logs of all sorts of tuned tdi's and the boost control is almost always very far from desirable. especially low rpm, huge boost spikes etc if you are heavy and quick with the pedal. if an n75 is "bad" and the tune is good, it shouldn't not be causing wild overboost, it should almost always cause underboost but with some overboost. IMO, a lot of people let themselves getting talked into blaming the hardware too often. now of course if you have sticky vanes that can obviously cause some nasty overboost an pop it

people really need to take more boost/etc logs and see how well there car is really running, and understand the numbers. imo, too many have been lulled into thinking you don't need to do this and trust that the tune/etc is all good. and if there's a problem, its almost always blamed on the hardware

 

[Shenandoah]

Folks,

Here a little more information on the Audi: The engine was from a 2002 Golf (automatic) that my daughter ran off the road and bent the unibody. It's got an 11mm injection pump. 5 speed manual transmission is from my 2005 Beetle (I put a 6 speed from RyanP in the Beetle). I've got a PD150 intake and the aluminum pipe that goes from the airbox to the turbo. Injectors have Bosio PowerPlus 520 nozzles. Stage 3 clutch. I've run the car in this set up for 4 years. Last year I had the ECU tuned with a Malone Stage 4 tune. I switched over to a 3 bar map when I had the ECU tuned

I don't really run the car hard, it's my daily driver. I was really surprised that the shaft sheared. As I mentioned I was going about 25-30 mph and passed a camper. I was in third gear and ran up to about 50 to pass. When I heard the loud "POP", I thought the turbo pipe popped off the intercooler but then when there was all the smoke and the car was idling along without me stepping on the accelerator, I knew something was wrong.

One thing I noticed this winter is sometimes when I would start the car I wouldn't hear the turbo "whine". Usually if I would step on the accelerator, I could hear the whine of the turbo (not flooring it, just gradually acceleration). Sometimes I wouldn't hear it and start down the road and the car would be in limp mode. I would stop, turn the key off and restart the car. After that it would be fine. I'm wondering if there was a problem with the turbo shaft binding? I did put a new braided steel oil line from the filter housing to the turbo when installed the turbo in 2017. I'm going to disassemble the failed turbo next week.

Once I get the new turbo installed and the car back on the road, I'll have to run another set of logs with VCDS to see if something has changed.

 

[burpod]

knowing what tune you have it makes a lot of sense to me sigh....

 

[Judson]

And I’ve been running a malone tune for years without an issue and so have literally thousands of others….

i hate it when one vendor trashes another. That’s the last thing we need. You think you can do better, great, but when thousands of people are running malone tunes for years without issues, it would require extraordinary evidence best provided from customers, not other vendors, to prove it’s the tunes rather than the turbos.

 

[PakProtector]

And I’ve been running a malone tune for years without an issue and so have literally thousands of others….

i hate it when one vendor trashes another. That’s the last thing we need. You think you can do better, great, but when thousands of people are running malone tunes for years without issues, it would require extraordinary evidence best provided from customers, not other vendors, to prove it’s the tunes rather than the turbos.

I don't think the evidence needs to be extraordinary at all. There are a lot of cars running Malone tunes( just to pick on him as this is the example ). I don't quite feel like going to the trouble to get one, log it, and then open up the file to see exactly what is going on. Yet.

With this failure there is no set of logs posted, or mentioned.

An 11mm pump and larger injectors is going to do best with *LESS advance than stock, and given the car is running a VNT17 it should have an N75 PID map from a VNT17 tuning. And a vane map that goes with the VNT17 and 414/11mm pump( this will be entirely different from an OE map), and then to keep good boost control those new maps depend on a modified fuel map( so the rest of the code understands just how much fuel is really going in).

Sooner or later somebody is going to put up a side-by side comparison. I have no doubt. Stock, bottled/off the rack and a thorough one...

Douglas

 

[KrashDH]

And I’ve been running a malone tune for years without an issue and so have literally thousands of others….

i hate it when one vendor trashes another. That’s the last thing we need. You think you can do better, great, but when thousands of people are running malone tunes for years without issues, it would require extraordinary evidence best provided from customers, not other vendors, to prove it’s the tunes rather than the turbos.

Lol, you ever looked at a Malone tuned log? Do you understand what a healthy log should look like?
The entire community took the tuning game at face value because no one knew any better. So now someone that comes in and understands the tunes and puts way more work into them, rather than just throwing a "blanket tune" out for many different configurations of hardware, you think that's "trashing"? That's called research, diagnosis, application, and improvement. The Malone tunes all show the same trends. Doesn't matter what stage.

If you have said tune, I'd say you should post up some logs for everyone to see.

 

[03TDICommuter]

And I’ve been running a malone tune for years without an issue and so have literally thousands of others….

i hate it when one vendor trashes another. That’s the last thing we need. You think you can do better, great, but when thousands of people are running malone tunes for years without issues, it would require extraordinary evidence best provided from customers, not other vendors, to prove it’s the tunes rather than the turbos.

Burpod is not a vendor and the Burpod thread has folks giving their evidence that his solution is better. So you point is off point.

 

[Windex]

Burpod (or his flying monkeys) seem to be using the same fear mongering once used by Drivbiwire.

Didn't work out well for him either.

 

[KrashDH]

Burpod (or his flying monkeys) seem to be using the same fear mongering once used by Drivbiwire.

Didn't work out well for him either.

No fear mongering. Just due diligence. Research. Patience. As well as more knowledge than you or anyone on this forum has with tuning.

If you're going to call someone out, post your proof.

Burpod is doing this on his own dime and time. How about the naysayers show some respect for someone who's taking their time to help the community with these vehicles?

Anyone can learn if you're open to knowledge.

Pretty bold calling people "flying monkeys" that understand more than you. We're here to help each other on this forum. What have you contributed?

 

[Nuje]

Burpod (or his flying monkeys) seem to be using the same fear mongering once used by Drivbiwire.

Didn't work out well for him either.

You've always struck me as better than that, Windex. If you're happy with your tune from BigTuneCo., say so, and enjoy your ride.
No need to denigrate the efforts of someone else here who's gone through a LOT of effort to not only learn for himself, but then help share that knowledge not just with posts, but by actually providing tunes and following up with numerous updates and tweaks based on feedback.

Pejorative comments contribute nothing.