Ok, we were getting the overboost code and limp mode under harder acceleration, so I ordered a turbo install kit and set out to clean the turbo vanes. A little back history first though...
- The car is new to us. 216K miles, lots of documentation from previous owners.
- 2005 Jetta Wagon with 5sp manual
- I have receipts for replacements of the N75, turbo actuator adjustment, MAF sensor, etc
- The PO claimed he replaced the turbo and that the car has a Malone stage 1 tune. Did not have receipt, but claimed turbo came from tdiupgrades.com. Actuator can is a Smart Actuator and appears to be line new appearance.
- EGR was deleted, but cooler was still installed.
- No engine codes other than overboost on occasion with spirited driving. Engine seems sluggish until about 2K rpm, then it pulls well.
- We are at approx 4500ft elevation
We dug into this by first doing some diagnostics. Put a vac gauge on the turbo actuator vac hose and ran the Group 11 test in VCDS. Vacuum goes from zero to 23-24, which seems correct. Used my Mighty Vac and connected to the actuator can, and it holds pressure fine, but arm didn't move much. With that info, we started by removing the intake, cooler and turbo, of course. Cleaned up the intake manifolds (split them and cleaned each half separately), then disassembled the turbo. Ends up the actuator module wasn't moving much because it was adjusted in essentially a fixed position (actuator rod was shortened such that the lever was against the stop screw). Removed the actuator and the lever flips back and forth easy and freely. We disassembled the turbo vanes anyways and cleaned it all up. Did NOT see any issues in there and cleaning was easy. Researched a ton to find instructions on how to adjust the actuator and stop screw. Set it so the actuator rod was fully extended with the vane lever in full out position, and set the stop screw with the actuator at 20 in Hg. Actuator started moving at about 4 in Hg it seemed.
Reinstalled everything with new gaskets, nuts, etc. The EGR cooler didn't make it back into the car (plugged the vac line, rerouted the coolant lines with couplers). Definitely need to get a good cable hose clamp plier!). Car started right up, went into VCDS and tried running the Group 11 test and initially it ran ok, but only got a change of 20-30 in boost pressure (I understand it should be 80 minimum up to 250). After running it several times, it now doesn't fully run, instead it ramps up the RPM and as it gets close to 1407rpm the rpm jumps to 1550-1600 and then comes back to idle. Obviously something isn't right.
Went for a drive and it has no power. We data logged the drive down the road and actual boost pressure is WAY low compared to commanded. Following some instructions I found on myturbodiesel, I tried backing the set screw off more. I also tried shortening the actuator rod (for more initial boost). At idle I see 829-849mbar...it's not even on the Live Scope display. It basically didn't change after the adjustments, but a test drive reveled even less power (couldn't get past 3K rpm in 1st gear). No trouble codes showing, nothing else seems amiss. Obviously I'm missing something.
- Does the Smart Actuator need to be calibrated/linearized? If so, how? I found discussions about it, but nothing seemed definitive.
- How do I properly adjust the actuator rod and stop screw?
It's obvious that the turbo is not the original KP39, but I have no idea what it actually is. It appears to have a VNT 15 inlet (stock size for KP39?), and the VNT 17/KP39 style outlet on the compressor side. The compressor looks like a billet 6+6 wheel. The exhaust turbine wheel is shaped like a VNT15/17 style with the cupped fins, not the smooth fins of the KP39. The actuator rod uses an E-clip/ball joint to connect to the turbo, not two nuts on a threaded rod, again like the VNT 15/17 pics I've seen. The smart actuator looks like a the same one from Kerma, not the stock KP39 style electronics. No name brand in the casting, no ID plate on the side, nothing. Shaft play seemed VERY reasonable, so I tend to think it's in good shape, just not idea what it is. Any advice on identifying it so I know what I'm working with?
Sorry for the long post, but trying to be complete and accurate. I'm tired of working on this thing and guessing, and could really use some help from those experienced with these turbos. Thanks in advance!
- The car is new to us. 216K miles, lots of documentation from previous owners.
- 2005 Jetta Wagon with 5sp manual
- I have receipts for replacements of the N75, turbo actuator adjustment, MAF sensor, etc
- The PO claimed he replaced the turbo and that the car has a Malone stage 1 tune. Did not have receipt, but claimed turbo came from tdiupgrades.com. Actuator can is a Smart Actuator and appears to be line new appearance.
- EGR was deleted, but cooler was still installed.
- No engine codes other than overboost on occasion with spirited driving. Engine seems sluggish until about 2K rpm, then it pulls well.
- We are at approx 4500ft elevation
We dug into this by first doing some diagnostics. Put a vac gauge on the turbo actuator vac hose and ran the Group 11 test in VCDS. Vacuum goes from zero to 23-24, which seems correct. Used my Mighty Vac and connected to the actuator can, and it holds pressure fine, but arm didn't move much. With that info, we started by removing the intake, cooler and turbo, of course. Cleaned up the intake manifolds (split them and cleaned each half separately), then disassembled the turbo. Ends up the actuator module wasn't moving much because it was adjusted in essentially a fixed position (actuator rod was shortened such that the lever was against the stop screw). Removed the actuator and the lever flips back and forth easy and freely. We disassembled the turbo vanes anyways and cleaned it all up. Did NOT see any issues in there and cleaning was easy. Researched a ton to find instructions on how to adjust the actuator and stop screw. Set it so the actuator rod was fully extended with the vane lever in full out position, and set the stop screw with the actuator at 20 in Hg. Actuator started moving at about 4 in Hg it seemed.
Reinstalled everything with new gaskets, nuts, etc. The EGR cooler didn't make it back into the car (plugged the vac line, rerouted the coolant lines with couplers). Definitely need to get a good cable hose clamp plier!). Car started right up, went into VCDS and tried running the Group 11 test and initially it ran ok, but only got a change of 20-30 in boost pressure (I understand it should be 80 minimum up to 250). After running it several times, it now doesn't fully run, instead it ramps up the RPM and as it gets close to 1407rpm the rpm jumps to 1550-1600 and then comes back to idle. Obviously something isn't right.
Went for a drive and it has no power. We data logged the drive down the road and actual boost pressure is WAY low compared to commanded. Following some instructions I found on myturbodiesel, I tried backing the set screw off more. I also tried shortening the actuator rod (for more initial boost). At idle I see 829-849mbar...it's not even on the Live Scope display. It basically didn't change after the adjustments, but a test drive reveled even less power (couldn't get past 3K rpm in 1st gear). No trouble codes showing, nothing else seems amiss. Obviously I'm missing something.
- Does the Smart Actuator need to be calibrated/linearized? If so, how? I found discussions about it, but nothing seemed definitive.
- How do I properly adjust the actuator rod and stop screw?
It's obvious that the turbo is not the original KP39, but I have no idea what it actually is. It appears to have a VNT 15 inlet (stock size for KP39?), and the VNT 17/KP39 style outlet on the compressor side. The compressor looks like a billet 6+6 wheel. The exhaust turbine wheel is shaped like a VNT15/17 style with the cupped fins, not the smooth fins of the KP39. The actuator rod uses an E-clip/ball joint to connect to the turbo, not two nuts on a threaded rod, again like the VNT 15/17 pics I've seen. The smart actuator looks like a the same one from Kerma, not the stock KP39 style electronics. No name brand in the casting, no ID plate on the side, nothing. Shaft play seemed VERY reasonable, so I tend to think it's in good shape, just not idea what it is. Any advice on identifying it so I know what I'm working with?
Sorry for the long post, but trying to be complete and accurate. I'm tired of working on this thing and guessing, and could really use some help from those experienced with these turbos. Thanks in advance!