Frozen VNT turbo - am I the only one

[Hasenwerk]

This is the third frozen VNT turbo that I have seen this year. Two VNT-15s frozen SOLID and one VNT-20 that moves a little. Basically with the lastest one, the VNT-20 in my camper applying vacuum to the actuator won't result in any movement more than a wiggle, using a screw driver I can move the mechanism about 50% of what it should move... I am assuming that these are full of soot and short of totally disassembling it and clearing the hot side, there is little one can do... so... what causes this? It is the fact that my VNT-20 R-TDI smokes like a freight train when I initially mat the pedal or is it just one of those things? Is there anything one can do to prevent this from happening?

 

[nicklockard]

Dave, is there any visible rust on the vacuum pot? Do you have lower engine covers of some kind? I'm just wondering if this could be a contributing factor. I know on stock cars that people who remove the lower covers have a much higher failure rate of these components (and others.)

But about soot: What's your mapping?

Can you show some pics of the failed items?

 

[LNXGUY]

You're sure its the vanes and not the actuator? I am sure soot could coke up the turbo, but man it would have to be a sh!tload....

 

[Hasenwerk]

Dave, is there any visible rust on the vacuum pot? Do you have lower engine covers of some kind? I'm just wondering if this could be a contributing factor. I know on stock cars that people who remove the lower covers have a much higher failure rate of these components (and others.)

But about soot: What's your mapping?

Can you show some pics of the failed items?

Everything is still mounted in my van. The VNT-22 that I have here moves very easy as compaired to the VNT-20 that is in my van - really stiff! If I attach a hose to the VNT-20 and suck and plug the hose with my tung there is a vacuum that remains - no leaks that I can see.

Mapping - the IQ is set to the lowest something like 2.5 IIRC, only smokes when I mat it and the turbo is starting to spool, when the boost comes on the smoke all goes away except for a slight whisp.

 

[Hasenwerk]

You're sure its the vanes and not the actuator? I am sure soot could coke up the turbo, but man it would have to be a sh!tload....

On the VNT-15s earlier this year - yeah - frozen solid. There is some movement on the VNT-20 but it is really stiff. The acuator holds vacuum and you can see it try to move the vanes, but it requires too much force.

 

[nicklockard]

*Note: I'm not a mechanic or wrench*

Was the turbo assembly done by you or pre-assembled, as purchased?

 

[Hasenwerk]

*Note: I'm not a mechanic or wrench*

Was the turbo assembly done by you or pre-assembled, as purchased?

It was a clocked 120 degrees by me and has been running for 1.5 year / 20.000 km / two oil changes in that position.

 

[Street Toys]

On the VNT-15s earlier this year - yeah - frozen solid. There is some movement on the VNT-20 but it is really stiff. The acuator holds vacuum and you can see it try to move the vanes, but it requires too much force.

Sorry to hear about your delema David, However have you tried to disconect the actuator from the lever? If you do this and try to move the lever you might see if it is the vanes themselves, then the lever would be stiff, or if the lever moves it most likly is the actuator . I have seen many actuators that rust up internaly and "freeze-up"! I'm sure that in your enviroment the the underside of your vehicle sees a lot more moisture than down here. I hope this can help you.

 

[doc_m]

........ Do you have lower engine covers of some kind? I'm just wondering if this could be a contributing factor. I know on stock cars that people who remove the lower covers have a much higher failure rate of these components (and others.)

I know it's not good to not have any covers on there but for some crazy reason till I installed my aluminum skid plate which thankfully i have now, I ran over 3 years and probably over 100k kms with no upper or lower covers and still managed to have the stock turbo and actuator. In no way am I saying it's can't be a contributor but being from the wet coast and having many drives to the interior of BC I thought for sure I would have corroded the actuator to bits by now and thus give me the final excuse to get a new tubo but I have had yet to kill it

 

[jayfrigginjones]

I have driven for over a year with no covers and as of yesterday, i no longer have an actuator . It rusted up and the rod snapped when i was removing it. Once out of the car i poured several grams of rust powder out of the acuator housing. Once i get the replacement, the lower cover is going back on. *Edit* forgot to mention that for 10 months of this time i was in colorado (MgCl on the roads) and 10 months in Albuquerque (nothing on the roads).

 

[Hasenwerk]

I am in Saskatchewan at this moment for a funeneral so trouble shooting is a little tough at this moment. But... there is a skid plate on the vehicl east is a Syncro Vanagon. The acutuator is also at the top of the turbo and there is a plate over the top of it that holds the water cooled intercooler. The actuator has a light covering of soot on it but as far as I can tell it is pretty far away from water. We'll do the removal of the turbo when I get back as I am going to build a custom exhaust manifold for it and install a GT2260 in it's place - along with a long runner intake manifold... good winter project.

 

[btcost]

if you suspect the vanes, pull off the egr plate and spray some foaming cleaner in therer. at the same time try to work the VNT.

with some elbow grease this should free up your vanes. or it's the VNT mechasism(sp?) that has failed.

hit www.tdiparts.com for that

also PM mrchill. he has been dealing that this issue for years and knows all the tricks.

btw. vanes tend to get choked up by driving like an old lady. We have never met, but I get the feeling that ain't your style.

so maybe, unfortunatly, you are droppin' VNT actuators

Brian

 

[turbobooster]

Just in case this helps anyone else, I'll share my experience this weekend with my VNT.

I have been questioning my turbo's health for a while, not knowing if it had a bad actuator, stuck vanes, or something else. About every third time I ran the boost up fully and let off for the next gear, the boost wouldn't come back very quickly. The turbo was very slow to spool for the next several seconds to several minutes. Shutting the car off and restarting it did not help.

I took the actuator's bracket off and tried moving the VNT lever. It moved smoothly from the fully down position to the middle. From there to the up position, it made a squeaky sound and got stuck, requiring a lot of force to pull it back down.

I tried working the lever up and down for about 15 minutes, but it did not get any better. Taking off the downpipe, I sprayed some carb cleaner into the hot side of the turbo and worked the lever. It then started to move more smoothly, so I worked it for a good ten minutes more and put everything back together.

I was worried about what would happen when I started the engine with a flammable liquid sitting in the turbo, but I couldn't live with stuck vanes any longer and decided I would live with whatever happened.

But nothing happened. The car started fine, idled fine, and it made the turbo spool up at idle like a tiny jet engine. I've gotten better mileage than ever with it and couldn't be happier.

The only downside was the work it took to get the three nuts off to release the downpipe. Well, that and knowing how much more difficult it will be now to convince the wife that I need a bigger turbo in the spring.

 

[Hasenwerk]

I'm back from my trip to Saskatchewan and while I was away the turbo fixed itself - well, with my help. As almost what turbobooster did, I sprayed the down pipe side with a very liberal amount of liquid wrench as well as a show down the EGR hole and when I came back everything moved a lot easier. I also installed new hose between the vacuum source, N75 and the turbo... drove 400km today and not a hint of problems.

Just in case this helps anyone else, I'll share my experience this weekend with my VNT.

I have been questioning my turbo's health for a while, not knowing if it had a bad actuator, stuck vanes, or something else. About every third time I ran the boost up fully and let off for the next gear, the boost wouldn't come back very quickly. The turbo was very slow to spool for the next several seconds to several minutes. Shutting the car off and restarting it did not help.

I took the actuator's bracket off and tried moving the VNT lever. It moved smoothly from the fully down position to the middle. From there to the up position, it made a squeaky sound and got stuck, requiring a lot of force to pull it back down.

I tried working the lever up and down for about 15 minutes, but it did not get any better. Taking off the downpipe, I sprayed some carb cleaner into the hot side of the turbo and worked the lever. It then started to move more smoothly, so I worked it for a good ten minutes more and put everything back together.

I was worried about what would happen when I started the engine with a flammable liquid sitting in the turbo, but I couldn't live with stuck vanes any longer and decided I would live with whatever happened.

But nothing happened. The car started fine, idled fine, and it made the turbo spool up at idle like a tiny jet engine. I've gotten better mileage than ever with it and couldn't be happier.

The only downside was the work it took to get the three nuts off to release the downpipe. Well, that and knowing how much more difficult it will be now to convince the wife that I need a bigger turbo in the spring.