New VNT-17, Hickup's under load....

[towforce]

Recently upgraded my KP39 to VNT-17 on my BEW, had posted this thread:

http://forums.tdiclub.com/showthread.php?t=499700

The upgrade went well and has solved my oil consumption issue. I really like the smoothness of the 17 but I'm now left with a new, minor issue that has yet to be resolved.... under steady load on a hill, mild throttle application, there is a very brief "hickup" or "stutter" (only a second or two), then back to normal. As much as I try, I can't force/duplicate the event.

No Codes are being logged. I have tested the throttle peddle output, seems normal with no issues. Cleaned various suspect connections (MAF and such).

We ran a interesting test where if we were on a hill holding at 2000 rpm or less and there would be no stutter, but if we held the same hill at 2200+rpm, we would get the occasional stutter.

I'm running a Malone Tune, Stage One that was setup for the KP39, I was told the tune would work with the 17 but I'm not sure if there is any differences that may be causing the issue.

I can't see it being related to a fuel issue, far too infrequent, if you punch it, the problem is gone (and like I said, can't force the event, its random and not very often). The stutter is so brief that I have yet to spot if the tach is jumping around so I doubt it is the cam sensor (?).

Anybody got any suggestions?

Thanks

Martin

 

[VincenzaV]

Very interested in the results of what you find. Bump!

 

[golfere]

Recently upgraded my KP39 to VNT-17 on my BEW, had posted this thread:
http://forums.tdiclub.com/showthread.php?t=499700
The upgrade went well and has solved my oil consumption issue. I really like the smoothness of the 17 but I'm now left with a new, minor issue that has yet to be resolved.... under steady load on a hill, mild throttle application, there is a very brief "hickup" or "stutter" (only a second or two), then back to normal. As much as I try, I can't force/duplicate the event.
No Codes are being logged. I have tested the throttle peddle output, seems normal with no issues. Cleaned various suspect connections (MAF and such).
We ran a interesting test where if we were on a hill holding at 2000 rpm or less and there would be no stutter, but if we held the same hill at 2200+rpm, we would get the occasional stutter.
I'm running a Malone Tune, Stage One that was setup for the KP39, I was told the tune would work with the 17 but I'm not sure if there is any differences that may be causing the issue.
I can't see it being related to a fuel issue, far too infrequent, if you punch it, the problem is gone (and like I said, can't force the event, its random and not very often). The stutter is so brief that I have yet to spot if the tach is jumping around so I doubt it is the cam sensor (?).
Anybody got any suggestions?
Thanks
Martin

I have the exact problem since ive put in a garrett vnt17 on my BEW; check the EGR valve as Ill bet if you unplug your EGR valve connector it will run perfect


I would upgrade to the stage 1.5 malone tune for $50 and send him a VCDS log so that you can maximize the tune to the new turbo; well worth the price and no overboost at all;


My car is still in the works of trying to figure this hesitation out! I need to replace my flywheel and clutch and ive read that some say it fixes the problem but idk...

 

[kidflyr]

Have you confirmed the VNT actuator rod adjustment? I recall reading that adjusting its length one way hastens response and can exacerbate boost spikes at the extreme of adjustment, the other way reduces the responsiveness of the VNT mechanism. The actuator isn't necessarily adjusted to spec by the manufacturer prior to delivery/installation.

The rod should be just long enough that there is just a tad of tension on the vnt actuator diaphragm spring when there is no vacuum applied.

Start to move off full open when 3-5 inHg vacuum applied, full travel stop at 18-22 inHg.
This is the garrett factory specs.[/QUOTE

Additionally, confirm whether the actuator rod moves smoothly through its range.

With my limited experience, the condition you described occurring with small pedal input changes, sounds like an actuator adjustment may be worthwhile.

 

[towforce]

Have you confirmed the VNT actuator rod adjustment? I recall reading that adjusting its length one way hastens response and can exacerbate boost spikes at the extreme of adjustment, the other way reduces the responsiveness of the VNT mechanism. The actuator isn't necessarily adjusted to spec by the manufacturer prior to delivery/installation.

The rod should be just long enough that there is just a tad of tension on the vnt actuator diaphragm spring when there is no vacuum applied.
Start to move off full open when 3-5 inHg vacuum applied, full travel stop at 18-22 inHg.
This is the garrett factory specs.[/QUOTE
Additionally, confirm whether the actuator rod moves smoothly through its range.
With my limited experience, the condition you described occurring with small pedal input changes, sounds like an actuator adjustment may be worthwhile.

Thanks for the instructions on the actuator rod. The VNT17, Bright and shinny out of the box, I just made the assumption that it would have been set correctly but its adjustment was a bit of a question as I dug into the problem. I will check it during the next oil change but I'm not sure it can cause what feels like a "fuel cut off" or a gasser's ignition miss..... you got to love a mystery!

Martin

 

[towforce]

I have the exact problem since ive put in a garrett vnt17 on my BEW; check the EGR valve as Ill bet if you unplug your EGR valve connector it will run perfect
I would upgrade to the stage 1.5 malone tune for $50 and send him a VCDS log so that you can maximize the tune to the new turbo; well worth the price and no overboost at all;
My car is still in the works of trying to figure this hesitation out! I need to replace my flywheel and clutch and ive read that some say it fixes the problem but idk...

Not really sure we are having the same issue, my "hesitation" is very brief and very random. There is a possibility the EGR valve is electrically having some issues (but not setting a code) but mechanically is clean and moving properly (the whole intake system was cleaned during the upgrade). Besides I want to retain the EGR system.... after all it did get me 480,000kms ;-)

The Malone stage 1 was more than enough for me (tho, I do get the addiction of having more and more power and was blown away by just how much the stage one produced). Even with only a stage 1 a near new LUK clutch has a bit of a shudder at full boost, I don't really want or need any more power and would like to be kind to the old "girl"....

M

 

[PakProtector]

Thanks for the instructions on the actuator rod. The VNT17, Bright and shinny out of the box, I just made the assumption that it would have been set correctly but its adjustment was a bit of a question as I dug into the problem.
Martin

Oh God no! I had to adjust mine. The only things I trusted to be adjusted properly were the stop screws...and mine did need some adjustment. It hit right on the 3 and 18 when I was done.
cheers,
Douglas

 

[Nevada_TDI]

towforce, I have a question: do you have VCDS and/or a boost gauge? Do you have the the error when you peg the throttle there is a bit of power coming, then the engine hesitates and then the engine puts out a puff of black smoke? Does the issue "go away" by cycling the throttle off and on? If so, there is a fairly easy fix to this problem.

 

[towforce]

towforce, I have a question: do you have VCDS and/or a boost gauge? Do you have the the error when you peg the throttle there is a bit of power coming, then the engine hesitates and then the engine puts out a puff of black smoke? Does the issue "go away" by cycling the throttle off and on? If so, there is a fairly easy fix to this problem.

I have the VCDS, but no boost gauge. Don't ever really EVER peg the throttle ... that would be like trying to give my 90 year old mother a swift kick ;-)... No big black smoke event with any of the gentle throttle apps that I give it. (Not saying she does not get a bit of an Italian tune up tho....)

Its not much in the way of a issue as its just this strange shudder/miss/hickup that happens over 2200 rpm and somehow related to perhaps backing off the throttle or very slight subtle changes in throttle application well under a minor constant load.

I think when I get a chance to pull the skid plate for the next oil change I will put the mighty vac on the actuator and see where the actuator actually goes and see if its set right.

M

 

[golfere]

Not really sure we are having the same issue, my "hesitation" is very brief and very random. There is a possibility the EGR valve is electrically having some issues (but not setting a code) but mechanically is clean and moving properly (the whole intake system was cleaned during the upgrade). Besides I want to retain the EGR system.... after all it did get me 480,000kms ;-)
The Malone stage 1 was more than enough for me (tho, I do get the addiction of having more and more power and was blown away by just how much the stage one produced). Even with only a stage 1 a near new LUK clutch has a bit of a shudder at full boost, I don't really want or need any more power and would like to be kind to the old "girl"....
M

My egr functions properly but for whatever reason it has hiccups around 2k rpm and when its unplugged it drives flawlessly.

 

[Jay-Bee]

I have a similar hiccup on my BEW w/ ALH turbo. Kind of sporadic boost before 2000 rpm, kinda jumps in, then off then back in, my clutch is hating it.

Tuner said I would need the N75 map adjusted, but after I sent them logs they say it's fine at full throttle, sure but my part throttle/cruise speed is what is affected the most, cruise control seems affected too when it tries to adjust speed for hills.

 

[Beaker80]

I have an 06 Canadian Golf with a dead KP39. I have bought a new Garrett VNT17 from TuneMyEuro.com (AARodriguez) to install and eventually add some tuning to it.

I was curious about the actuator travel mentioned above so I got out my vacuum tester. The actuator starts to move at 4 in.Hg and is fully open (on the stop) at 19 in.Hg. So I'm happy that it's set up properly.

 

[aircooledkid]

Did you figure anything out op?

 

[Nevada_TDI]

Jay-Bee are you 100% sure your actuator arm is set right? Your turbo is a vnt-15, is that correct? If so, the mapping for a vnt-15 is slightly different, here is an possible example: at a given amount of vacuum a vnt-15 will produce less boost that a vnt-17 at the same amount of vacuum. So at low RPM your turbo could be iffy or hunting, but at full throttle the request for boost is satisfied. You also mention when on cruise the power is not following to maintain requested speed.
Does this help?

 

[towforce]

Did you figure anything out op?

Sorry!.... I will followup, but it is such a minor glitch that I have yet to crawl under the car to get at the Actuator and check the adjustments on the rod. Gauge is on the bench and ready to go, might get to it this weekend.


M

 

[towforce]

Ok, pulled the skid plate, dug out my Mighty-Vac and did the tests. My, brand new, out of the box IDP VNT-17 BEW turbo actuator was perfect, 3-4 psi, off of the start and moved smoothly through to 18psi full stop. Even vacuum tested the hoses from the top down and no issues. Well at the actuator, I cleaned the contacts of the sender...not much else to do... other then admire the fine work I had done on the whole job

Maybe the next step will be try unplugging the EGR if I can figure out exactly trips the event... love a mystery.

M

 

[Nevada_TDI]

Use Your VCDS

Sorry!.... I will followup, but it is such a minor glitch that I have yet to crawl under the car to get at the Actuator and check the adjustments on the rod. Gauge is on the bench and ready to go, might get to it this weekend.


M

When you have time, hook up VCDS and log into "Boost Requested-Boost Actual." Do the 3rd gear performance test: slowly go through first and second gear, shift into 3rd gear and stand on the throttle until you to a speed that won't get you a ticket. Logging that will give you a lot of information.

 

[towforce]

When you have time, hook up VCDS and log into "Boost Requested-Boost Actual." Do the 3rd gear performance test: slowly go through first and second gear, shift into 3rd gear and stand on the throttle until you to a speed that won't get you a ticket. Logging that will give you a lot of information.

Your request is my comand.... (don't have a clue what I'm looking at tho... I see a spike and below request reading but have no idea what is normal ;-)

 

[towforce]

I have the exact problem since ive put in a garrett vnt17 on my BEW; check the EGR valve as Ill bet if you unplug your EGR valve connector it will run perfect

Golfers, you would be correct! Unplugged the EGR valve and it runs perfectly. After unplugging the valve another symptom seem to disappear, a minor lumpy idle. My bet is this very high mileage part has probably had enough of being cleaned and is just giving up. I will pull it and give it one more super clean but I suspect the seals are gummed up on the shaft and its sticking.. if the cleaning fails I'm going order a new valve. (Mind you, still curious if the Malone Tune has anything to do with when the valve is actuated when it come to the two different types of turbos?).

Martin

 

[towforce]

Thought I would follow this thread up with what turned out to be the cause of the "stumble/hesitation" after my turbo replacement.

Yes, unplugging the EGR valve did point the blame to the valve. On the various occasions that I had pulled the valve out, cleaned and inspected I really could not find any obvious faults. What I found interesting was adding the step of pulling the electrical cover off of the valve itself.

Much to my surprise I discovered there is a substantial amount of soot that can migrate through the valve body and valve stem seal. Of course this "soot" gets into everything under the cover including the position sensor, gear motor and actuator.

On the last time this valve got pulled (to install the new valve), I noted that the valve was not fully closed and was in fact hanging up.

New valve installed, running perfectly.

As to why the problem cropped up after the turbo change? No idea, just bad luck.... I guess

Cheers

 

[BobnOH]

Any power upgrade will bring out any little issues that exist.
Thanks for posting solution!