Clean or replace turbo?

Redman84

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I'm near 265k on original turbo. Throwing the stupid intermittent over boost code. Have all new vac lines and the VNT actuator tested ok w mity vac. Still need to check the n75 w VCDS but if that tests out well should I even bother with cleaning it or just get a new one?
 

AndyBees

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Shaft play

Is there enough room to check shaft play w it still in the car?
Yep! Just remove the hose on the suction side of the Turbo and stick your finger in there and feel the end of the shaft .... jiggle it up and down. There will be some up and down (side-ways) movement. There should be virtually zero in and out movement. You will find some oil inside there too. What counts is how much oil you have to add during the 10,000 mile change interval.

The clamp on the hose is in a tight place, but it can be removed!

The Turbo on my 2000 Jetta has 354k miles on it and has never been off or cleaned..... works great! I have to add about 1/2 quart of oil by the end of the oil change interval.
 

Jake_S

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Yup. Remove the outlet pipe, and check for excessive axial (in and out) movement of the turbine.

Jake
 

AndyBees

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If you can push the shaft in, you should be able to pull it out. Thus, you are looking for the amount of "in and out" movement. ...... which should be virtually zero!
 

[486]

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If you can push the shaft in, you should be able to pull it out. Thus, you are looking for the amount of "in and out" movement. ...... which should be virtually zero!
if you can get your fingers on the compressor wheel through the compressor outlet you've got better fingers than me (winky emoticon)
 

AndyBees

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if you can get your fingers on the compressor wheel through the compressor outlet you've got better fingers than me (winky emoticon)

Fingers on the "compressor wheel" isn't necessary, and, no doubt impossible as per the circumstances being discussed in this Thread.

Through the Compressor "inlet," push on the end of the shaft, then pull out on it, either with your fingers or needle nose pliers.








Back to the OPs original question, the issue may be something besides a "dirty" Turbo as you've already suggested. I'd eliminate those things before attempting to "clean" the Turbo.

There are two options to clean the Turbo, do the chemical clean (huge long Thread on the pros and cons) or remove the Turbo and disassemble on a work bench. Complete disassembly is not recommended (taking out the Turbine Shaft), as you run the risk of getting the assembly out of balance.

Check out my photo gallery for Turbo pics relating to cleaning.

http://pics.tdiclub.com/showgallery.php?cat=5302
 
Last edited:

Rembrant

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There are two options to clean the Turbo, do the chemical clean (huge long Thread on the pros and cons) or remove the Turbo and disassemble on a work bench.
I just cleaned a VNT-15 turbo on the bench last week...and I was surprised at how well it worked. I have to admit...I didn't read the huge long thread, so I don't know what the "cons" are, and maybe I don't want to know.:D

Although the VNT actuator was rusted out, it still held vacuum, but the VNT lever stopped at about 2/3 travel.

I put the nozzle and straw from a can of Brake cleaner on a can of oven cleaner so that I could reach as far as possible in behind the exhaust turbine wheel. I had a couple cleaning sessions over a couple evenings, and would work the VNT lever with my fingers while the turbo soaked. I even filled the CHRA oil cavity with fresh engine oil so that nothing would get in there while cleaning.

The VNT now has full travel and the operation is smooth.

I would definitely clean and inspect an old turbo before buying a new one...they are expensive after all.
 

[486]

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02 golf ALH
Fingers on the "compressor wheel" isn't necessary, and, no doubt impossible as per the circumstances being discussed in this Thread.
well that's what I get for trying to be jokingly pedantic
 

BobnOH

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central Ohio
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New Beetle 2003 manual
For the cost of a proper replacement, definitely consider taking it to the bench and cleaning it.
 

Redman84

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Lots of good replies. Thank you all. My oil consumption has gotten up to +- 1 qt over 10k miles with no appreciable leaks(small occasional drip originating at valve cover). I'll test the N75 hopefully this evening and also try and check the shaft play too.
 

vtpsd

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cleaning the turbo isnt too bad, i would try that. I was able to get mine spotless inside with oven cleaner. They work effortlessly when properly cleaned.
 

[486]

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02 golf ALH
I used 'dry moly' (molybdenum disulphide) spray on mine when I put it back together. ZEP makes it, it's like graphite lube but fancy and space age. There was some rust in there, so I figured either that or rustoleum barbecue grill paint.
 

AndyBees

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Being serious..

[486] ............ I just now noticed that "winky emoticon." ;)

Well, this afternoon, I did check a Turbo I have on the bench. My little long skinny fingers will latch onto the end of the Turbo shaft ..:)

Okay, here's an interesting thought. There have been several discussions (Threads) about Turbo rebuilding, rebuilders, do it yourself kits, etc., with lots of naysayers and supporters on both sides. Primarily the naysayers thought is that any kits would be CRAP (Chinese Replacement Auto Parts) and that the rebuilders would not do a "proper" balance (both static and dynamic at high speed).

Anyway back to the thought ...... Doing a "chemical clean" without removing the Turbo, in my opinion, is risky from a balance stand-point. How do you know whether or not the OC resulted in a uniform cleaning.

Let me clarify. Did the OC leave some junk sticking to a few of the Turbine blades? Did one side of the Turbine receive a better cleaning than the other side? If your guess is, probably so. Then, don't you think the result is a Turbine out of balance? Keep in mind, the VNT15 spins up to 200,000 RPMs, thus, the need for that perfectly balanced assembly..

:D:D:D:D:D:D

In my opinion, proper cleaning can only be achieved on the bench with the CHAR removed from the Exhaust housing ..... The crud in the Vane mechanism can be unbelievable as demonstrated in the pic below. (see my photo gallery link above)



Below, that same Vane assembly after cleaning.



Again, there are lots of pics in the link to my photo gallery posted previously in this Thread.
 

Redman84

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Alright, I got under it this afternoon and cycled the n75 w VCDS. Looked to me like the actuator rod was moving without issue maybe an inch of travel or a little less. The charge pressure being read when "ON" was 99.6%.

I also pulled the inlet hose and was able to get my thumb and first two fingers(small hands) on the shaft. I didn't perceive any movement in and out but then again I couldn't percieve any up and down either which is suppose to be normal.

So does that indicate a bench cleaning or is there more to check first?
 

jettawreck

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Interesting thought about the OC method Andy.
As always, the turbo pics in your gallery are great.
I've yet to have a VNT 15 fail, or need cleaning bad enough to use either method, but I've still got a spare from the original 2001 "jetta wreck" on the shelf somewhere that only has 33k miles on it. Maybe if I get back to the gas/diesel swap project in the spring I will pull the old one off the 2003 donor and install the "new" one.
Your pics will be referenced repeatedly if the "old" one gets dismantled and cleaned up.
 

[486]

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[486] ............ I just now noticed that "winky emoticon." ;)

Well, this afternoon, I did check a Turbo I have on the bench. My little long skinny fingers will latch onto the end of the Turbo shaft ..:)
.
what I was pointing out was that the compressor outlet is in the side of the compressor cover and the inlet is the center
he'd said to put your fingers in the outlet, and that may have caused future confusion to someone
 

AndyBees

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Interesting thought about the OC method Andy.
I've yet to have a VNT 15 fail, or need cleaning bad enough to use either method,.................
Me neither.

However, back about 7 or 8 years ago, when folks began to experience "bad" Turbos, I purchased a good number of them..... still have a pile in my garage. I've gradually disassembled, cleaned and sold a good number of them.

As for a failed(ing) VNT15, about 5 years ago, I installed a "very" marginal Turbo (very long story) on a 99 NB (owner was well aware). Three years later (last I saw of it), it was doing just fine.

So, I'm sure there is a very unique story about each and every failed Turbo. However, in my opinion, the vast majority were at the "foot" of a lot of abuse. And, I'm sure many of them provided some warning signs.

Back to the OP's question. The instant that the engine is started, if everything is working properly, the Actuator on the Turbo should pull the lever down to the stop screw. At idle, it should stay in that position.
 

mrrhtuner

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Again, there are lots of pics in the link to my photo gallery posted previously in this Thread.

Hello Andy, you wouldn't have a DIY link or know of a good one to follow with having the turbo off the car?

I'd like to clean mine as I've heard from a local tdi guru that mine is a bit gummed up.
 

AndyBees

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Hello Andy, you wouldn't have a DIY link or know of a good one to follow with having the turbo off the car?

I'd like to clean mine as I've heard from a local tdi guru that mine is a bit gummed up.

Nope! No Thread, but I've thought about taking a sequence of pics for that purpose. I just might do that over the weekend.;)
 

mrrhtuner

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Nope! No Thread, but I've thought about taking a sequence of pics for that purpose. I just might do that over the weekend.;)

From somebody that seem's like they know what they are doing, it would help the rest of us out greatly.
 

300D

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Nope! No Thread, but I've thought about taking a sequence of pics for that purpose. I just might do that over the weekend.;)
I too would be interested. I have the PDF by Drivebiwire, which I think will work well, but with very little text, my OCD brain wants more information before diving in.

I too am considering the clean vs replace decision. One side of me says if I am going to go through all the trouble of pulling the whole thing out, then I should just stick a brand spanking new one back in. The other side of my brain says, BUT you can save $750 and keep using the old one!

I did the oven clean a few days ago and the results after hours of pain and suffering under the car in 20 degree weather are just not as good as I hoped it to be. I also replaced the actuator and that little circlip was just about the death of me.

I hate the idea of pulling out the old turbo, putting it on the bench, pulling it apart and then discovering that it's got some issues that aren't fixed by cleaning. Then the car sits without a turbo until new one arrives. Which means I sit without a car.

Anyway, lots of pics and lots of detailed instructions would be great. :)
 

Nero Morg

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I've torn apart and cleaned the vanes on the turbos that are in 3 cars I've brought back from the dead, one of them is one I just had a stage 2 Malone done and it's operating just fine. The secret is not scratching anything and making sure it's so clean you'd be willing to eat off of it. I have a few torn apart on my workbench right now if you need any pictures of the guts of the turbo.
 

AndyBees

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Well, this Thread is over 3 years old... I suspect all those needing to see the pics I promised are pissed....... Sorry!:eek:
 

Nero Morg

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Well, this Thread is over 3 years old... I suspect all those needing to see the pics I promised are pissed....... Sorry!:eek:
Lmao hop to it then! Or I can upload some if someone wants it. These turbos are pretty simple.
 
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