stomachbuzz
Well-known member
Skip to bold for TL;DR
I've been browsing for a couple weeks, and I'm very impressed by the TDIclub community. One of the strongest and most vibrant forums I've come across in my years of surfing. Really excited to have this forum as a resource.
A bit of background: I'm a 23 y/o mechanical engineering student, and I have moderate to advanced levels of mechanical experience. Car owner and driver for ~8 years now. In the beginning (and even now) I had to do my own work to save money, and with a happy byproduct of learning a lot! Over the years, I've done almost any car repair possible short of taking the short block to a machine shop for rebuild. I've done many a ball joint, tie rod, wheel bearings, steering racks, brake calipers/rotors/pads, chased down drivability issues, auto to 5 speed swaps, pulled engines, etc.
And it seems like this TDI I just picked up might need all of those things!
Ha, just kidding. It's not quite that bad, but that's what I'm here to figure out.
I just bought a 2000 Golf 4 door GLS TDI (of course) w/153k. Unfortunately it is an automatic, but we will see about that.
I recently picked this thing up as a sad 'toss around' with a broken coolant flange and trans in limp mode.
I replaced the coolant flange, and driven it ~40mi. It starts off in 2nd, shifts harshly into 3rd @4k rpm, then shift harshly into 4th at 4k rpm again. It won't go into 1st gear on its own, nor will it shift into overdrive. It will go into first if I shift it manually.
Additionally, the motor seems to run a little funky at times.
First of all, easiest starting motor I've ever come across! Hit the key for microsecond and that diesel is chugging away.
Aside from the transmission issues, the motor seems to have no power at times. Shortly after start up, seems like it has a huge vacuum leak under throttle. It will approach 2k RPM fine, but when I give it more throttle it has no additional power and feels like when a gas motor has a vacuum leak and it's about to stumble under load. Going up hills (even in 2nd gear) is hard.
Then maybe 30 seconds later, it seems to have its regained mid-top end umph and will pull rather nicely into the higher RPMs.
Even when it feels like it has no power, it doesn't miss a beat.
I haven't found a good way to check the trans fluid as it's a sealed unit, but I did pull the codes. I'm using a semi-professional grade "CPReader Launch 123"
The codes were P0722 -Output speed sensor No signal, and P0730 - Incorrect Gear Ratio.
These codes line up pretty well with my situation.
The seller's theory was that the hot coolant from the broken flange dumped right onto the speed sensor and fried it. Seems plausible, but can't remember the last time life was that easy for me.
Additionally, I went into the 'other side' of the scanner. I don't really know what this is, but it's not the regular OBD2. It's just called 'scan' and it yields a TON more data than OBD2. SRS, ABS, traction control, transmission codes, etc.
2 new codes:
P1144 - Mass airflow sensor short circuit to ground
P1556 - Charge press. ctrl. lower control limit
The MAF was unplugged when replacing the coolant flange. I plugged it back in.
I understand it's common to unplug the MAF to diagnose limp mode, but no idea. Previous owner didn't provide any clues.
A couple issues:
I have no idea what a TDIs is supposed to feel like. I don't know if it is actually low on power or "that's just how they are".
I have zero experience on turbo motors, so no idea how to diagnose charge tubing or a boost leak or anything along those lines.
Thanks in advance for the help!
I've been browsing for a couple weeks, and I'm very impressed by the TDIclub community. One of the strongest and most vibrant forums I've come across in my years of surfing. Really excited to have this forum as a resource.
A bit of background: I'm a 23 y/o mechanical engineering student, and I have moderate to advanced levels of mechanical experience. Car owner and driver for ~8 years now. In the beginning (and even now) I had to do my own work to save money, and with a happy byproduct of learning a lot! Over the years, I've done almost any car repair possible short of taking the short block to a machine shop for rebuild. I've done many a ball joint, tie rod, wheel bearings, steering racks, brake calipers/rotors/pads, chased down drivability issues, auto to 5 speed swaps, pulled engines, etc.
And it seems like this TDI I just picked up might need all of those things!
Ha, just kidding. It's not quite that bad, but that's what I'm here to figure out.
I just bought a 2000 Golf 4 door GLS TDI (of course) w/153k. Unfortunately it is an automatic, but we will see about that.
I recently picked this thing up as a sad 'toss around' with a broken coolant flange and trans in limp mode.
I replaced the coolant flange, and driven it ~40mi. It starts off in 2nd, shifts harshly into 3rd @4k rpm, then shift harshly into 4th at 4k rpm again. It won't go into 1st gear on its own, nor will it shift into overdrive. It will go into first if I shift it manually.
Additionally, the motor seems to run a little funky at times.
First of all, easiest starting motor I've ever come across! Hit the key for microsecond and that diesel is chugging away.
Aside from the transmission issues, the motor seems to have no power at times. Shortly after start up, seems like it has a huge vacuum leak under throttle. It will approach 2k RPM fine, but when I give it more throttle it has no additional power and feels like when a gas motor has a vacuum leak and it's about to stumble under load. Going up hills (even in 2nd gear) is hard.
Then maybe 30 seconds later, it seems to have its regained mid-top end umph and will pull rather nicely into the higher RPMs.
Even when it feels like it has no power, it doesn't miss a beat.
I haven't found a good way to check the trans fluid as it's a sealed unit, but I did pull the codes. I'm using a semi-professional grade "CPReader Launch 123"
The codes were P0722 -Output speed sensor No signal, and P0730 - Incorrect Gear Ratio.
These codes line up pretty well with my situation.
The seller's theory was that the hot coolant from the broken flange dumped right onto the speed sensor and fried it. Seems plausible, but can't remember the last time life was that easy for me.
Additionally, I went into the 'other side' of the scanner. I don't really know what this is, but it's not the regular OBD2. It's just called 'scan' and it yields a TON more data than OBD2. SRS, ABS, traction control, transmission codes, etc.
2 new codes:
P1144 - Mass airflow sensor short circuit to ground
P1556 - Charge press. ctrl. lower control limit
The MAF was unplugged when replacing the coolant flange. I plugged it back in.
I understand it's common to unplug the MAF to diagnose limp mode, but no idea. Previous owner didn't provide any clues.
A couple issues:
I have no idea what a TDIs is supposed to feel like. I don't know if it is actually low on power or "that's just how they are".
I have zero experience on turbo motors, so no idea how to diagnose charge tubing or a boost leak or anything along those lines.
Thanks in advance for the help!
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