chase345
Member
Can someone please tell me what I have going on???
Here's some background....
2006 TDI 250K miles, EGR delete, great car, no big problems, except for this one which has been plaguing me for years.
I have low/sluggish boost at RPM's under 1800. Accelerating through 1800 I get a surge of boost and its like a breath of fresh air to the engine and it suddenly makes power. Before that, it will hardly get out of its own way, especially if you allow it to dog down low in 2nd or 3rd gear.
In an attempt to adjust the VNT rod, I broke the VNT actuator. This led me to replace the turbo with a new one. I figured, ehh, 250k on the car, it's probably time for a new one anyways, right?
So I installed the new turbo hoping that all of my boost/actuator issues would go away.
....The problem still exists, almost identically.
I have checked vacuum leaks, MAF, the actuator begins to move at around 3-4psi and bottoms out around 18psi which I'm told is correct.
The actuator moves freely with no sticking points what so ever. No engine codes. WHAT IS GOING ON?
I managed to stick my go pro under the hood to observe the VNT actuator in action during a short drive accelerating through 1st 2nd and 3rd gears.
You can see that it starts out fully extended and shortens commanding more boost. The point at which it stalls is evident on the video and is right around that 1800 RPM mark. After that, a big rise in power and the turbo slows down as if a load has been placed on it. Does this make sense?
Link to YouTube video here
You can hear the turbo spool rapidly and the "load down" accelerating through 1800 or so. This is when the actuator moves and I can feel the power spike.
Please forgive the flashing in the video. My flashlight rigging experienced some vibrations.
I am desperate to find the cause of this issue. If anyone has any advice or if I can clarify further, please let me know.
Here's some background....
2006 TDI 250K miles, EGR delete, great car, no big problems, except for this one which has been plaguing me for years.
I have low/sluggish boost at RPM's under 1800. Accelerating through 1800 I get a surge of boost and its like a breath of fresh air to the engine and it suddenly makes power. Before that, it will hardly get out of its own way, especially if you allow it to dog down low in 2nd or 3rd gear.
In an attempt to adjust the VNT rod, I broke the VNT actuator. This led me to replace the turbo with a new one. I figured, ehh, 250k on the car, it's probably time for a new one anyways, right?
So I installed the new turbo hoping that all of my boost/actuator issues would go away.
....The problem still exists, almost identically.
I have checked vacuum leaks, MAF, the actuator begins to move at around 3-4psi and bottoms out around 18psi which I'm told is correct.
The actuator moves freely with no sticking points what so ever. No engine codes. WHAT IS GOING ON?
I managed to stick my go pro under the hood to observe the VNT actuator in action during a short drive accelerating through 1st 2nd and 3rd gears.
You can see that it starts out fully extended and shortens commanding more boost. The point at which it stalls is evident on the video and is right around that 1800 RPM mark. After that, a big rise in power and the turbo slows down as if a load has been placed on it. Does this make sense?
Link to YouTube video here
You can hear the turbo spool rapidly and the "load down" accelerating through 1800 or so. This is when the actuator moves and I can feel the power spike.
Please forgive the flashing in the video. My flashlight rigging experienced some vibrations.
I am desperate to find the cause of this issue. If anyone has any advice or if I can clarify further, please let me know.
