Turbo Preventative Maintenance

Having been struck twice with catastrophic turbo failure while on road trips, the first 500 miles from home and the second 50 miles, I have wondered how to prevent the reoccurrence of a third such failure.

The first failure was at 78K miles and due to "high altitude surge." The bearing was still near perfect, but the shaft parted. The second failure at 138K was due to bearing failure on the exhaust side. Both times, a large quantity of crankcase oil flowed into the exhaust. I replaced both turbos myself, and wrote the Turbo How To in Wingnuts fine collection after the first failure.

What I am going to do from here on out is to examine the turbo shaft for movement on each oil change. If I detect any movement, I will rebuild the turbo with a new bearing and related parts.

On the second breakdown due to failure of the bearing, I had noticed some oil usage a couple of weeks prior to the failure. This was a red flag that something was wrong, I now realize. If I ever notice a sudden oil drop, I am again going to check the turbo shaft for movement, as well as the bottom of the intercooler for oil.

My thoughts are that turbo shaft bearing failure is not a sudden occurrence, and some periodic diligence in checking the shaft for movement should prevent breakdowns and the related expense. There is a Garrett VNT15 rebuild kit from Japan being sold on eBay for about $80.00. This is cheap compared with the costs of breakdown and a new turbo. Does anyone have any experience with this kit?

Can any of you experienced turbo mechanics out there add any other periodic checks to make for bearing failure, or telltale signs of impeding turbo bearing failure?

With these cars, I think that some sort of turbo check procedure is probably mandatory to keep from getting broken down a long way from home.

Regards,

Speedster,

I'm curious what oil you've been running in this engine?

And on a side note, can you post a pic of your speedster replica?

Kirk

Oil has been Shell Rotella 5W40 synthetic since new. I checked the shaft and supply tube for any signs of coking, and there were none. I have no idea why the bearing on the second turbo failed. Just one of those things!

I have never posted a pic on the site, so will need to do some research to post a pic of my Speedster.

Regards,

Speedster Pictures

Kirk,

I have successfully uploaded some pics of my Speedster and motor to my member album. If you have any questions about the car, do not hesitate to ask.

My wife and I use the car for shows and just cruising around town on nice balmy evenings. It really garners a lot of looks and some "thumbs up."

Regards,

Speedster Pic

Here it is.

Great looking car. Can you cram a RC3 ALH in there and stand it on it's rear?

This is probably in your write-up, but I might as well ask here since lots of folks will see this thread: how do you check the shaft play w/o removing turbo?

I'm imaging you pull the inlet tube for access to the compressor wheel, but I'd be reluctant to poke my fingers (or anything else) in there without knowing what I'm doing.

Eddy

Checking turbo shaft play

Remove the air inlet hose from the intake side of the turbo. This takes some spring clip pliers. Just move the hose out of the way. This is easy to do since it is rubber. Just inside the opening is the compressor wheel that can be felt with the fingertips.

Remove the three nuts on the exhaust downpipe coming out of the turbo. Squirt a little WD-40 on the threads if you have never remove them before. On reassembly, put some antisieze on the threads. The downpipe move easily out of the way also due to a flex connection.

With the air inlet hose and downpipe off of the turbo, both the compressor wheel and the exhaust turbine wheel are accessible to the fingertips. Pinch the shaft nut on each end with two fingertips and slowly rotate the wheels. Move the shaft both back and forth and axially. The idea is to see if you can feel any noticeable play between the shaft and bearing. It should rotate smoothly with no noticeable wobble. If you can clearly wobble the shaft on either end with you fingertips, you have too much clearance and should consider a rebuild. Failure to rebuild is like running a timing belt past its mileage limit and hoping nothing happens!!

Once you perform this check the first time, it will only take about 10 minutes on each subsequent oil change. While under there, it would also not be a bad idea to check the movement of your turbo vanes. This can be done with a vacuum pump like Mity-Vac, or I have read from above using a mirror while the ignition is cycled on and off. The third way to do it is to simply take a 10mm wrench and take out the two small screws that hold the vacuum pot onto the turbo. With the vacuum pot removed, you can move it and the pot output shaft back and forth to verify the vane actuator arm movement. It should move about 1/2' at its outer tip. Movement should be very free.

I am currently working with another local TDI owner who just bought a used, auto trans, TDI with only 40K miles from a woman. She evidently babied the engine. He knew that the engine was not performing, and I suggested that he check the vane movement using the third method of screw removal. The test verified that the vanes were frozen in place. Now, he is going to remove the turbo and use the excellect vane cleaning article by Drivebiwire to get the turbo going again. It is important to rev the engines in these cars to keep the vane assembly free of exhaust soot. I rev my TDI in first and second gears over 4K rpm at least once each day, and normally shift at 3K all other times. With auto transmissions, they must be manually shifted to clean the turbo vanes. I am sure the the first owner of my friend's TDI simply drove it like any other auto equipped car and the engine never saw much rpm.

Regards,

Diesel Speedster

Hey ChromeBuddha,

I thought very briefly about a diesel powered Speedster, but the weight distribution would be too extreme. However, if I had it to do all over again, I would seriously consider building a Porsche Spyder, ala James Dean, with a mid-engine ALH. It would surely be the only diesel Spyder on the planet, would make Porsche purists turn inside out , and would probably get 60-70 mpg due to such light weight.

It is too bad the the VW Lupo diesel is not sold here. With its 3 cylinder, aluminum TDI engine, it would be near perfect for a mid-engine swap. At 75 mpg in the Lupo, it would probably get close to 100 mpg in a Spyder. As a publicity stunt, VW had a driver and mechanic drive a Lupo TDI around the world. The car averaged about 113 mpg. I am sure that they pumped the tires up till they were hard as rock, and never drove over 50 mph to achieve that mpg. Quite impressive!

Next lifetime!!

Regards,

Speedster said:

It is too bad the the VW Lupo diesel is not sold here. With its 3 cylinder, aluminum TDI engine, it would be near perfect for a mid-engine swap.

Click to expand...

From Bleached Bora's Bargain Bin.

~Engines (New)
Contact for shipping costs--depending on location and if you're at a residence or not they are $150-$300 for a 400 lb. engine.
-BKD Euro PD 2.0 TDI Crate engine --- $5899
-ALH 1.9 TDI Crate engine --- $5699 (2 left as of 28 October--when they are gone they are gone)
-ATD Euro PD 1.9 TDI Crate engine (works with BEW as well) --- $5799
-BMD 1.2 TDI 3-cyl VW Polo engine $4699 --- OUT
-1.6L to 1.9L non-TDI conversion 028 100 018K --- $3999
-AHU Longblock --- $3899
-ALH Longblock --- $3999
-OEM VW Kolbenschmidt .50mm oversize TDI Piston Set (for 1Z, AHU and ALH) with 80mm bore, includes rings, wristpins and clips --- $950

Currently out.... but you now have no excuses.

Speedster said:

Having been struck twice with catastrophic turbo failure while on road trips, the first 500 miles from home and the second 50 miles, I have wondered how to prevent the reoccurrence of a third such failure.

The first failure was at 78K miles and due to "high altitude surge." The bearing was still near perfect, but the shaft parted. The second failure at 138K was due to bearing failure on the exhaust side. Both times, a large quantity of crankcase oil flowed into the exhaust. I replaced both turbos myself, and wrote the Turbo How To in Wingnuts fine collection after the first failure.

What I am going to do from here on out is to examine the turbo shaft for movement on each oil change. If I detect any movement, I will rebuild the turbo with a new bearing and related parts.

On the second breakdown due to failure of the bearing, I had noticed some oil usage a couple of weeks prior to the failure. This was a red flag that something was wrong, I now realize. If I ever notice a sudden oil drop, I am again going to check the turbo shaft for movement, as well as the bottom of the intercooler for oil.

My thoughts are that turbo shaft bearing failure is not a sudden occurrence, and some periodic diligence in checking the shaft for movement should prevent breakdowns and the related expense. There is a Garrett VNT15 rebuild kit from Japan being sold on eBay for about $80.00. This is cheap compared with the costs of breakdown and a new turbo. Does anyone have any experience with this kit?

Can any of you experienced turbo mechanics out there add any other periodic checks to make for bearing failure, or telltale signs of impeding turbo bearing failure?

With these cars, I think that some sort of turbo check procedure is probably mandatory to keep from getting broken down a long way from home.

Regards,

Click to expand...

Is the engine modded?

I heard on here before that there are no bearings in the turbo. I havn't seen a explode view of these turbos. So, are you sure they have bearings??

i know this is off topic, but i love the wheels on that speedster. beautiful car, thanks for sharing.

Speedster said:

It would surely be the only diesel Spyder on the planet, would make Porsche purists turn inside out .

Click to expand...

Oh, I don't know about that... there are diesel Porsches, you know. They've already got their own website and registry, in fact:

http://www.porsche-diesel.com/

Thanks for the info on the turbo check! Maybe not every oil change for me, but at the next one, or maybe when I'm in there installing my EGT probe, for sure...

Eddy

The turbo shaft spins inside a bronze bearing, with a pressurized oil layer hopefully keeping them from actual contact. If you want an exploded view, go to the British site www.melett.com for parts.

Other than the egr modification, no modifications to the engine. No chips or bigger injectors.

Regards,

Turbo Failure Reasons

I have thought for many days about my two turbo failures, why they occurred, and why they should have lasted a whole lot longer.

The first failure occurred due to "high altitude surge" at over 6,000 feet. The turbo simply spun itself to death, causing the shaft to part. The shaft bushing was still good at 78K.

The second turbo was acquired off of eBay from a car that had only 4K miles on it when the pan was sheared off by taking a speed bump at too much speed. After putting the turbo on the car, I noticed an oil leak. Eventually, I determined that the leak was coming from a crack in the aluminum plate that is part of the turbo cartridge. I took it to a diesel shop and had them replace the plate with the one from my old turbo. The oil leak was cured, but this turbo lasted only 60K miles. Why?

After corresponding with Melett in England about turbo parts, I was advised that all wheels and shafts had to be VSR balanced if I wanted the turbo to have a long life. This is a process of dynamic balancing where the wheels are balanced at high speed while attached to the shaft.

Since the wheel/shaft assemblage spins at up to 200K rpm, it is critical that the assembly be free of imbalance. The shaft rides in a bronze bushing that is filled with pressurized oil from the crankcase. There is a clearance of only about .002" between the shaft and bushing. The plan is that the pressurized oil keeps the shaft from touching the bushing. The finely finished metal seals at the ends of the bushing keep the oil inside the bushing, along with the higher pressures from both the turbine wheel and the compressor wheel.

What causes the bushing to wear must be simple imbalance caused by carbon build-up on the turbine wheel or the assembly being unbalanced. Garrett probably performs the VSR balance to ensure long life. When I had the cartridge taken apart to replace the aluminum plate, the assembly was not rebalanced, which resulted in premature failure.

To ensure that the assembly remains in balance, it is also very important to drive the engine hard at least once per day to burn soot from the turbine wheel. Accumulated soot on the turbine wheel will also cause it to lose it precision balance.

So, I am suggesting that the turbo only be checked for play when and if the engine suddenly starts using more oil than normal. The play between the shaft and bushing can just barely be felt with sensitive fingertips. It is probably not necessary to check the play at each oil change.

On a related issue, I assisted a fellow TDI owner in cleaning his vanes on his recently acquired TDI auto with 40K miles. The vanes were so frozen up with carbon soot that not even the ring would rotate in the housing. If you drive an auto, it is very important to manually shift once per day to get the rpms up to about 4K. I'll bet that VW does not advise auto buyers of this little fact.

Regards,

First off, lets clarify something because the BS is getting a bit deep in regards to turbo's.

If you increase fueling in your car (chip, injectors, tuning box) you completely null and void the software that is designed to work with the EXTREMELY fast responding VNT turbo (I don't care if it's a VNT 15,17, 20 or 23) if you over fuel and provide enough energy for it to accelerate faster than the software was designed to control it it will GRENADE!

Turbos that fail DO NOT SHEAR SHAFTS as the "Primary Cause of the failure".

The turbo bearings at least all the "blown up ones" that I have seen had bearings that looked as new as the day they were installed.

The VNT bearings for the most part are bullet proof.

As far as play there is NO WAY you can determine the condition of a turbo by "touching" the turbo...Sure it may give you a warm fuzzy but unless you have a calibrated fingertip the ony thing you are doing is moving the shaft around inside a bearing that is not supported by oil pressure.

If you are feeling play at the compressor hub do not forget that you are feeling the play located exactly 65mm (to the center of the bearing support) and all you are doing is rocking the shaft and not detecting actual clearance.

Without digging up the specifics, the critical value is not whether you can rock the shaft up down, or side to side but in fact IN and OUT. The turbo shaft has a critical value in regards to keeping it "centered" on the bearing and not just for the sake of the bearing but for the "centering Mechanism" and seals (2) within the turbo. If the bearing has excessive play (in and out) this could point to excessive wear on the centering mechanism within.

Now, if you have play (side to side, up and down) ignore it! It has to be there! If you do feel it keep in mind that you are feeling the play at the end of a 65mm arm, it's like guessing the play in a teeter Totter bearing while grabbing the end and moving it up and down...You can't!

However the play you can detect is the range of motion "in and out". However unless you have a dial indicator you're just guessing. And for the most part if this play is "excessive" it's accompanied by high oil consumption because the turbo's seals (2) are damaged from excess play...



DB

Drivbiwire,

Thanks for the benefit of your knowledge on this matter. Your drawing is worth more than a whole lot of words. What I was suggesting is getting people to at least check the small amount of play in their turbo shafts to see what is "normal." Then, if there is suddenly a change in oil consumption, they may be in a position to make more of an intelligent judgment on the play in their turbo shaft. If it still feels "normal," then the cause of excessive oil usage may lie elsewhere.

You stated, "Turbos that fail DO NOT SHEAR SHAFTS as the "Primary Cause of the failure."

My first turbo failed at 78K with a sheared shaft. The car is stock except for the EGR mod. It was running really nice, as usual. It was a rainy night in Castle Rock, Colorado as I stopped at a stop sign. My turn led uphill and there were cars coming up the hill. I gunned the fuel, heard the engine rev up and suddenly lose rpm. This all happened in about 1/2 second. There were no CELs. The bushing was perfect. All that I had was a parted shaft and turbine wheel that destroyed itself by flying around the exhaust housing. I had read about "high altitude surge" on the site and assumed that this was the cause. It made logical sense to me at the time. If not, then I am still stumped by the sudden failure.

I have noticed from the Melett website that they offer both straight and slender shafts and paired bushings. We have the slender set in our turbos. The straight shaft would be stronger, but there must be some reason why VW specified the slender shafts. They are only about 3/16" in diameter between the larger shaft journals on both ends of the bushing. Just wondering.

On my most recent turbo failure, the bushing on the turbine end had at least .030 play. The bushing inside diameter on the turbine end was visibly larger than on the compressor end, allowing a rather large amount of crankcase oil to squirt into the exhaust. My simple logic led me to believe that imbalance in the assembly caused the shaft journal to come into contact with the bushing, eventually causing the failure. Again, no CELs. In the weeks prior to the failure, I had noticed that the engine was using more oil. Now I know to check the turbo if I ever see this condition again.

I have been wrong on so many things in the past that I could be really off on the reasons for my turbo failures. Hopefully, my brand new stock turbo will not suffer the fate of the first two and I can get many trouble free miles out of it.

Regards,

Speedster said:

It is important to rev the engines in these cars to keep the vane assembly free of exhaust soot. I rev my TDI in first and second gears over 4K rpm at least once each day, and normally shift at 3K all other times. With auto transmissions, they must be manually shifted to clean the turbo vanes. I am sure the the first owner of my friend's TDI simply drove it like any other auto equipped car and the engine never saw much rpm.
Regards,

Click to expand...

Are you SURE the automatics must be manually shifted?
I run mine (Tiptronic) up past 4000 RPMs with just my right foot. So far at 38k miles, my PD has not been babied at all - driven how DrivBiWire recommended for breakin since it's still a baby...
Regards!

your second turbo failure was lack of oil. if the pan was cracked inthe doner car then it ran out of oil and starved the turbo at 200000 + rpm. impressive to get the milage you did out of it. ive seen it many times on forrestry equipment, Engine running at full load a stick will get it to the engine compartment and rips off the oil line. usually the turbo wont get to full load again before it fails.

Speedster said:

Drivbiwire,


You stated, "Turbos that fail DO NOT SHEAR SHAFTS as the "Primary Cause of the failure."

My first turbo failed at 78K with a sheared shaft. The car is stock except for the EGR mod. It was running really nice, as usual. It was a rainy night in Castle Rock, Colorado as I stopped at a stop sign. My turn led uphill and there were cars coming up the hill. I gunned the fuel, heard the engine rev up and suddenly lose rpm. This all happened in about 1/2 second. There were no CELs. The bushing was perfect. All that I had was a parted shaft and turbine wheel that destroyed itself by flying around the exhaust housing. I had read about "high altitude surge" on the site and assumed that this was the cause. It made logical sense to me at the time. If not, then I am still stumped by the sudden failure.

Click to expand...

Forget about the shaft shearing, that was a "secondary" failure.

The compressor probably threw a blade and wend out of balance. The resulting flexing of the shaft at high rpms, the deflection due to the out of balance finally permitted the compressor to dig into the housing, the inertia of the turbine twisted the shaft causing it to snap at the the compressor bearing support point. The bearings will have indicated some abrasion due to the severe loads imparted on them.

In that 1/2 second the turbo made contact with the housing no less than 1500 times probably at 1600 impacts it dug in and snapped the shaft...People forget how fast these turbos are going and how little time it takes to grenade.

I have noticed from the Melett website that they offer both straight and slender shafts and paired bushings. We have the slender set in our turbos. The straight shaft would be stronger, but there must be some reason why VW specified the slender shafts. They are only about 3/16" in diameter between the larger shaft journals on both ends of the bushing. Just wondering.

Click to expand...

Again the shaft is of no concern to these turbos. It's only when the compressor goes out of balance that the shaft will fail. No matter how thick you make it the fatigue that builds in the shaft will cause it to fail. If you double the thickness the turbo will still fail, maybe not in 1/2 seconds but in 5-10 seconds.

On my most recent turbo failure, the bushing on the turbine end had at least .030 play. The bushing inside diameter on the turbine end was visibly larger than on the compressor end, allowing a rather large amount of crankcase oil to squirt into the exhaust. My simple logic led me to believe that imbalance in the assembly caused the shaft journal to come into contact with the bushing, eventually causing the failure. Again, no CELs. In the weeks prior to the failure, I had noticed that the engine was using more oil. Now I know to check the turbo if I ever see this condition again.

Click to expand...

I agree with that. I too would suspect an out of balance if the bearing is worn to that degree.

DB

letting a turbo engine idle after pulling into the drive for a few seconds will save the bearing wear. lets the turbo speed decrease so the bearing has oil once engine is shut off. if you have a powered up drive and whip into the drive and shut the engine off your turbo will be going at high speeds and when oil supply isnt there it will not have lube and wear out the bearing. only sure way to prevent turbo blow up is to not have one. i have seen million mile turbos and five hundred mile turbos. failures are never pretty. and change your air filter and clean out the air piping going to the air filter housing. otherwise it all gets sucked back into your new turbo.

JimTDI said:

Are you SURE the automatics must be manually shifted?
I run mine (Tiptronic) up past 4000 RPMs with just my right foot. So far at 38k miles, my PD has not been babied at all - driven how DrivBiWire recommended for breakin since it's still a baby...
Regards!

Click to expand...

Yeha, I found out (by accident) that i stomp on my accelrator, mine will turn up past 3200. (01M trans)

Speedster said:

If you drive an auto, it is very important to manually shift once per day to get the rpms up to about 4K. I'll bet that VW does not advise auto buyers of this little fact.

Regards,

Click to expand...

Yeah, and and the mean time, we're pounding our already delicate pos transmissions and accelerating wear. So we save a $1600 turbo and replace a $4k transmission earlier then we might have hoped for.

While I agree with your facts and conclusion on this, I find it utterly retarded to have a design like this.

Which car is this on and how many miles are on it? I have a 2000 Jetta with 141,000 miles and the only things I have done is the timing belt water pump and 1 new fuel filter. Car runs like new to me.

Oh and I live in Colorado and have been over the mountains several times with this car. I live at 5400 feet and every one knows the passes are over 10,000 ft.

Lefty said:

I have a 2000 Jetta with 141,000 miles and the only things I have done is the timing belt water pump and 1 new fuel filter. Car runs like new to me.

Click to expand...

I suggest that you might be the exception to the rule. You're lucky. At least in my view. I'm at 91k with my '01 and there is no END to the repairs that have to be made-including one turbo already. (I expect there to be even more turbo failures-but hopefully not more than one, if that.)

How can you tell if the vanes are getting sticky? I can easily drive at 3k and 4k rpm's. If the vanes were stuck would the car be sluggish above 2k?

If the vanes are sticking you usually get an overboost.

The VNT is driven to full boost as soon as you start the engine. Once the turbo starts making boost the ECU based on programming for the turbo control decreases the VNT range to control boost within pre-determined pressure and flow levels. This range of pressure and flow varies based on temperature, altitude, local atmospheric pressure, air temperature and a few others.

If you are getting an overboost code, more than likely the VNT is not able to return to the low/no boost position due to carbon buildup in the turbine area.

Underboost points to an issue with the N75, MAF, Fuel, Fuel shut-off selenoid, leaks in the intake and other factors.

DB

High oil consumption

Still getting oil in intercooler since my last post on this subject, I have been driving my car differently - trying to keep engine in boost condition. Does this meen turbo bearings are bad?

I'm bumping this because I'm kind of curious as to what people are now thinking about all this some 10 years later.

I've got five ALHs. All turbos are operating perfectly normal. Some history:

Car 1: 2000 Golf, my car, was obtained with 114k miles on it. PO owned it for 12 years and was an extremely light-footed person. Car had had it's oil changed every 5k miles (using some expensive oil). Intake and EGR valve were horribly clogged when I got the car: interesting note is that it was a pretty dry caking, unlike most other clogging that I've seen which is pretty tarry/oily. Turbo, though constrained by the restricted intake, did not feel sticky. Following cleaning the intake and valve the car ran very well and has since then (now with larger nozzles and a stage 2 tune). My oil consumption is higher than any of the other cars, a good quart every 10k miles: I put in almost 1 qt around 5k miles; when I hit 10k miles I'm down, but keep forgetting to note how much. Recently have had some wired noise pop up that almost sounds like a small fan blade tinging away (don't hear it all the time, mostly at idle; goes away with an increase of RPM): hoping that this not a turbo noise!

Car 2: 2000 Golf, wife's car, purchased with 143k miles on it. It ran great from the start: and compared to my car, which had not yet cleaned it's intake; it felt extremely quick! There was a slight hesitation right around 3,200rpm, a hesitation that I figured was due to sticking vanes; but, it was fairly mild, didn't think it was any big concern. I closely watched oil buildup in the lower iC, draining it every 5k miles, over concerns about the turbo. Generally see 2 to 3 ounces. Oil consumption, on the whole, is perhaps 1/2 - 2/3 qt per 10k miles. Over the course of nearly 2 years I'd exercised the turbo until, one day, I realized that the sticking point was no longer there- the car runs straight on through that 3,200rpm area without any hesitation at all.

Car 3: Daughter's 2003 Jetta wagon. Bought last spring with about 162k miles on it. It's a Canadian car (lives up in Canada). While doing the TB on it I noted that the turbo is NOT a stock VNT15; it's off a 100hp euro engine (my mind is blank right now on what it is, but it's a slightly larger compressor wheel). I did a lot of test driving and logging with it in order to observe the behavior of the 01m (taking a risk here! - it was rebuilt not too long ago, or so are all the indicators) and it's always run very well/hard. Until the turbo oil feed line went on it it wasn't, best I could tell, using any oil; thankfully, the turbo survived the event- I'll be watching as closely as I can (given that the car is a good 1 1/2 hours away).

Car 4: Son's Golf, 2003 with roughly 160k miles. Also a Canadian car, living up in Canada. This car is nearly perfect in every way. He did trip limp mode once following getting a tune (stage 3). No awareness of any oil consumption or any turbo issues.

Car 5: My wife's and my spare 2000 Golf. Just got this a few months back: got it from a member on this site. 205k miles. PO tells me to watch the oil consumption. Car has same nozzles and tune that our other two Golfs have, but it has an 11mm IP and a 6spd. Original VNT15, though the vanes and backing plate were cleaned (by the PO). So far, in about 3k miles of ownership I have not seen any measurable oil consumption.

Anyway, just kind of interested in hearing more about what people have found with regards to turbo maintenance. What works. What doesn't work.