Is this too much play in my turbo impeller?

"I know a new actuator won’t fix my hard start"

Actually, it just might. No expert here, but it's my understanding that the turbo is "actuated" on startup. That's why you should see it move on starting. A boost of extra air and therefore some fuel.

One of the things I've recently figured out on cold startups, teens this neck of the woods is cold, is that I'd frequently get some white smoke. Unburnt diesel. Like many used to gas motors, I give it a bit of throttle while cranking, extra fuel right? Wrong!

Let the glow plugs do their thing and turn the key. Bingo, starts fine, no smoke,,, then give it a little throttle. Lol, old habits.

The computer has it figured out, it advances the timing, the bit of boost gets the extra air/fuel into the cylinder, and off the little diesel goes.

Don't pump the throttle!

Yeah, I responded to the PM.

I agree with the previous assessments relating to timing. As I understand, you have VCDS. If so, you need to check the timing first hand yourself. Seems there is a How-To on the procedures. Or, just do an Internet search. And, I agree with your assessment that the Turbo is not the cause of hard starts.

Sure, elevation is a factor, but we don't see lots of posts similar to yours from folks living at higher elevations.... Thus, there is a cause that can be found.

Make sure that replacement EGR is not trying to close the butterfly. Maybe disconnect the vacuum hose and plug for a few cold starts... just a thought.

EDIT: The engine has to be started to make Vacuum. Without Vacuum, the Actuator does nothing... It takes about 3 to 5 seconds after starting for the Actuator to pull the arm down tight on the set-screw....... and, that is not boost position! (Observed very easy on the ALH in my Vanagon!)

Thanks so much for all the help and info everyone!



Great to know about Frans as an option, but the ones with a warranty are rebuilt and are $450. Used ones are $275.



After going back and forth a bunch I think I'm going to go with a new actuator and see if cleaning this turbo has any effect. I'm just not seeing enough evidence to point to bad bearings and blow by, which would be the last remaining question mark on this unit. I will log it and see if any values changed from pre to post cleaning. My lady also pointed out that if I do decide to replace the whole thing sooner than later, it will go a lot smoother now that I know the procedure and because all the bolts have been (for now) unstuck and cleaned.



Once I get the car running I will go through the list of everything you have suggested to check. Lots to look into and learn!

The engine has to be started to make Vacuum. Without Vacuum, the Actuator does nothing... It takes about 3 to 5 seconds after starting for the Actuator to pull the arm down tight on the set-screw....... and, that is not boost position! (Observed very easy on the ALH in my Vanagon!)


Oops, I stand corrected, my bad. I'll stand by my starting prodedure but. And what Andy said, the ASV (automatic stop valve), could be

playing up, that's vacuum controlled. Could have a bad N75 valve.

this thread has me worried about my 250,000km turbo. VNT17 or replacement VNT15 if mine eventually fails?

Just check the actuator and turbo play. If it looks good don't sweat it.

Andrew Dale said:

this thread has me worried about my 250,000km turbo. VNT17 or replacement VNT15 if mine eventually fails?

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If it isn’t broken, don’t try to fix it!

Personally, I’ll go with a vnt15 if I need to replace it, but there is lots of info out there for the 17 if you do ever want to go that route.

How are you guys judging torque on the flare fittings for the oil feed and return lines. The only value i can find is 30 ft lbs for both (myturbodiesel.com - they claim 30 for the unions themselves and the flares). The lowerr turbo bracket is listed as 30 and cranking that hard on either flare seems way high to me.

I do good and snug. Keep watch and if you get a leak at either joint give it a little more.

Interesting name choice you have there. Rock climber?

While you wait for your actuator to arrive check the N75 for clogging.
It may have some rust from the old actuator keeping it from functioning normally.
It can be blown out with 'dust-off' or low-pressure compressed air.

Tdijarhead said:

I do good and snug. Keep watch and if you get a leak at either joint give it a little more.

Interesting name choice you have there. Rock climber?

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Indeed - climber and Hackers fan .

flee said:

While you wait for your actuator to arrive check the N75 for clogging.
It may have some rust from the old actuator keeping it from functioning normally.
It can be blown out with 'dust-off' or low-pressure compressed air.

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Will do, thanks!

climbtheplanet said:

If it isn’t broken, don’t try to fix it!

Personally, I’ll go with a vnt15 if I need to replace it, but there is lots of info out there for the 17 if you do ever want to go that route.

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whoops, i have a different turbo than the ALH. definitely replacing the borg warner with a Garrett (especially since its basically the same price).

AndyBees said:

I've never seen a VNT15 with zero play.

The Turbo on the engine in my Vanagon had about half that the play as the OPs Turbo at 129k miles (when I got the engine). It has over 208k miles and is about the same.

Jokila, how long had your 417k mile Turbo been sitting on the shelf? Some of the stash I purchased back 8 to 10 years ago feel like they have zero play until they are "freed" up from sitting so long. There has to be clearance, otherwise, the bushing and shaft would seize pronto without oil.

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It was about 2 months of non use. I sold it and that guy says it runs great. Rotella T6 for about 370K of its life, the rest was Motul syn blend in the beginning.

So a brand new turbo has a wobbly shaft?

Yes, the impeller can be physically rocked, can remember someone replacing one at work and finding the same movement in the new one. If it has too much movement there will be contact and it shows. Oil pressure keeps it centered.

Jolkia, I really haven't had the luxury to examine a "brand" new VNT15. But, I have examined, disassembled, etc., numerous Turbos with less than 175k miles on them. The shafts in all of them had noticeable movement, however, none of them were scraping the housing. Residual oil (room temp or colder) will give a bit of false sense of a "tight" shaft/bushing. I've seen that many times. Spray some WD-40, penetrating oil, etc., down the oiling hole and it will free-up and the "wigglement" can be discerned.

The ALH engine in my Vanagon come from MrGutWrench's wrecked 02 Jetta. As I understand, he maintained it well using spec oil. Since it has been in my Vanagon, I've done the same, Shell Rotella T6. The Turbo shaft movement today at 208k miles is about the same as it was at 129k miles when I installed the engine.

I suspect that once the movement is enough for the Impeller to be pushed against the housing, it could be considered out of spec.

As Jmodge said, oil pressure keeps it centered. Also, the method of how exhaust gases hit the Turbine in the VNT Turbo keep it centered. Unlike traditional waste-gate Turbos that are designed to direct the exhaust gases onto the blades in a constricting circle beginning on one side of the Turbine, the Vanes of the VNT Turbo direct the hot gases 100% evenly from a 360 degree circle onto the Turbine blades.

Update: New actuator is coming tomorrow, otherwise most of the car is put back together. In the mean time I sucked out any oil in my intercooler and only got out about 1 ounce, and I’ve never had oil come out when I’ve disconnected the lower tube. Doesn’t mean I’m not getting vaporized blow by and/or turbine side leakage, but I know it’s not dumping a stream of oil into the intercooler.

I will do an update once I get it going again. Can anyone here help me with interpreting my before and after boost logs, or recommend someone who can? I don’t know what healthy or common values and deviation are.

climbtheplanet said:

........................... Can anyone here help me with interpreting my before and after boost logs, or recommend someone who can? I don’t know what healthy or common values and deviation are.

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See Post#4 in this thread

Update:


I got the new actuator and old turbo installed and there is good and bad news. The good news is that the car is definitely running better in general, I have better and more consistent power through the rpms, better throttle response and the boost and MAF logs are much better than they were before. The turbo is creating boost the way it should and is not overboosting near as much as it was before. So, the mechanism and the actuator (I believe both) for sure needed some TLC.

The bad news is there is no immediate evidence that the problems I am actually trying to solve are solved. I'm still rolling coal when I drop a gear and mash the pedal, and the car didn't start super awesome this morning, though it still did OK and I will need to monitor it over the coming days for that. My exhaust still smells rich in a way that I can only describe as "oily, thick and strong," though in saying that I'm not suggesting the smell is of burned motor oil, it seems to me to be more a diesel smell. I recleaned the intake while I had the turbo off even though it was still pretty clean so it is not a manifold problem.


As per the suggestion quoted below I have done some more testing:

csstevej said:

If the timing is off , statically , it will affect the way it runs.
Also if the static timing is good and the dynamic timing is at the low end of the graph you will have a hard time starting when cold .
If you IQ is set too low , towards 2-3 , you are over fueling , it needs to set to 3-4ish.
To do this ( dynamic timing and IQ ) you need vcds or at least access to one.

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csstevej said:

I would first check static timing, rent , borrow or buy the tools, they will pay for themselves.
Then check your dynamic timing, I suspect static is off.
When was the timing belt done and by who?

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Timing in basic averages 64-65. VCDS lists the midline at my testing fuel temp of 98 degrees F at about 55 and high limit at 75, and confirms that I am in range and advanced.

(Edit) I read up on timing some more and went back to check the dynamic numbers. They specified and actual were both at 2.0 BTDC.


My injection quantity fluctuates between 4.8-5, so I'm right on the money there, which is where I set it a few years ago after doing a IP reseal. I may still be running rich, but the IQ is not indicating it.

I will test the whole vac system and solenoids soon, though I do know I'm getting the boost that I should and I replaced every vac line including the brake booster line last summer.

As this all started happening I did start to use more oil, but it has never seemed dramatic. I just went from never having to add any between oil changes to having to top up occasionally. With that in mind I am going to monitor my oil consumption closely over the next few thousand miles and see the true amount it is actually using. I have been battling a weaping vac pump and valve cover for a long time, so while I had the time I took those off, resealed what I could and went for some RTV this time in hopes of fully stopping the leaks so I know 100% any oil I "lose" is oil that is being used/burned, though I doubt the pump and cover contributed to any appreciable oil loss - it was never enough to reach the ground. My fuel economy also seemed to go down, so I will pay closer attention to that as well.

Questions:

Would you all recommend advancing the timing even closer to the high limit?


Is there another timing reading I can check or did I get them all?

There's really only two timing components to worry about on these cars. Mechanical timing of the timing belt, and dymanic injection timing with VCDS. I read a lot on where to put the timing on these engines, some say a little advanced will help with power, but as close to the midline will help overall with fuel economy and performance. I'd try to stick with that.

Did you change out the MAF? I had a bad MAF in my old 00 Golf. Every time I pushed the go pedal it left a cloud of smoke. I changed it out and no more smoke. The only problem with the change out is only a Bosch works correctly and they are over $100.

Tdijarhead said:

Did you change out the MAF? I had a bad MAF in my old 00 Golf. Every time I pushed the go pedal it left a cloud of smoke. I changed it out and no more smoke. The only problem with the change out is only a Bosch works correctly and they are over $100.

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No, but it’s on the list of possibilities. Vcds seems to show it measuring correctly though. I’m trying hard to not replace things that don’t need it bc chasing this rabbit is starting to get expensive with not a lot of results.