Turbo replacement issues

Got the new turbo in. Adjusted the rod length and set screw. The rod stops moving at 18inHg. I also replaced the boost solenoid. Before replacing the solenoid, the car smoked like nobodies business. Now it runs fine, without smoke.

I hooked up the VAGCOM and watched the graphs - reset learned settings. The boost runs low at idle..If it wants 900, it is getting 750. The air intake is only half the calculated value.

I hooked a vacuum gage into the line going to actuator, and a vacuum gun to the actuator. By hand I reproduced the vacuum reading from the gage. Trying different amounts of vacuum, the under boost didn't change.

There aren't any leaks from turbo to intake.

Not throwing any codes.

CCV tube from valve cover to intake is off. Waiting for new heater to arrive.

Any ideas?

The reading is low at idle because the turbo is hardly moving at idle but as long as off idle it stays pretty consistent, actual versus desired you should be ok

I took it out for a spin last night with VAGCOM hooked up. At low RPM, under-boost. At higher RPM >1500 = over-boost. There was very little smoke to begin, but after about a minute of driving, tons of white smoke. I'm thinking the stop screw or rod length is off.

What N75% numbers are you getting?

What turbo did you install that required an adjustment???

And why was this turbo replaced to begin with?

White/blue smoke is unburned fuel (misfire), or engine oil.

White steam smoke is coolant.

Black smoke is burnt fuel and/or not nearly enough air.

Nevada_TDI said:

What N75% numbers are you getting?

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Max 80% at idle, under load/acceleration it bounces around between 30-80%

oilhammer said:

What turbo did you install that required an adjustment???
And why was this turbo replaced to begin with?
White/blue smoke is unburned fuel (misfire), or engine oil.
White steam smoke is coolant.
Black smoke is burnt fuel and/or not nearly enough air.

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Turbo shredded itself. Can a bad vacuum modulating valve cause a turbo to eat itself?

A "premium" turbo from Turbo Pros. Out of the box, the actuator rod was too short. It hit stop screw at 10inHg. Starting to think they sent me the wrong one.

Get a proper new turbocharger from a reputable vendor. Garrett is who made the OEM turbo.

oilhammer said:

Get a proper new turbocharger from a reputable vendor. Garrett is who made the OEM turbo.

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I am starting to lean in that direction.

If the actual airflow is half of what is being requested, what could cause that? It makes sense that it's blowing white in black smoke if the computer can't get the air/fuel ratio right.

Nothing blocking the charged part of the intake.
No Leaks
Intercooler cleaned - plenty of metal bits laying in the bottom

You think not having the ccv tube connect would cause this problem? The ccv heater disappeared so the hole in the intake where this goes is plugged. Maybe air getting in after the MAF? I have the CCV heater coming today so I can get everything connected.

Check online and with the vendor that they sent you the right turbo. If it's the wrong part then you might be $hit out of luck since you installed it.

imo000 said:

Check online and with the vendor that they sent you the right turbo. If it's the wrong part then you might be $hit out of luck since you installed it.

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Double checked with them. The Garrett number on turbo is GT1749VA. They sent me a GT1749V. Not sure if the V and VA are the same. I know the 1749VB is different.

They are willing to send me a garret for the price difference from the one I already have.