Joined
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5 Posts
Ok, another limp home story....
1999 New Beetle TDI purchased in, 1999. I am the original owner and It currently has 190,000 miles on it. In 2005 an Upsolute chip was added by Bahn Brenner, the local Upsolute representative. I am in the Cascadian region of the planet.
My spouse is the regular driver, me rarely. Up until this month I had experienced Warp Field Collapse only twice (in 6 years). I really did not think to much about it. I was beating it when it happened.
Now, I find myself driving over the local pass from Western Washington to Eastern Washington on a regular basis. To make this drive you have to go over one big mountain (Stevens Pass) and one smaller one. Now we have repeatable verifable high boost induced limp home mode. And funny, memory serves, the two previous failures were on every large hills while being beaten.
Regardless, I started following the well know and documented repair proceedures to fix the problem.
1. Verified that every inch of the intake system was in proper working order.
The entire intake system was removed and cleaned including the screen, intercooler, and EGR system. The intake manifold was replaced with a new one. The air filter was replaced.
2. I added a McNally boost gauge with EGT read out. The pressure sensor is in the intake manifold just after the EGR valve. I have issues threading holes into plastic as recommend by the manufacturer. (
The EGT sensor is in the exhaust manifold with the thermocouple placed to the drivers side of the turbo.
3. Every inch of vacuum tubing was replaced with properly sized VW factory tubing.
4. Vag-Com testing showed fault with the N75 device. That was replaced
5. The VNT acutator arm was cycled and no binding or rough operation was noted.
6. The VNT vacuum diaphram was tested, works like a charm.
7. For fun the Injectors were replaced because, why not. We had a little more smoke than we like. (The smoke is gone now) (
8. No leakes are dectable in the intake or vacuum system.
Ok, the scary part.
Climbing the pass is obviously a high load event for the engine. I like to pass cars up hill. On the four lane sections you try to at least go the limit. I like to run the cruise control when I can too. Now that I have a boost sensor, I have found that the boost gauge regularly spikes (and the spikes are slow) reads in excess of 25 PSI. Usually the pressure slowiy drops to 14 PSI and no problem other than fear. If I am trying to "maneuver", flooring the throttle when the boost is already that 20+ PSI leads to a rapid jump to 30+ PSI. This pegs the meter and ocassionally after a few long moments, limp home mode. Restarting resets the programing.
When 30 PSI is noted, the EGT spikes to 1,000 degrees F + or - a few.
I am guessing that 30+ PSI is a little steep and that 1,000 deg F EGT is high? WE know limp home is not correct.
Regardless, since the N75 was replaced the VAG-Com tests are not regestering any failures. Also, other than the high load limp home epsides and scary scary high boost readings this car runs like a champ. No smoke, no starting issues, excellent fuel economy, zips around fine. Love the Upsolute chip (I think).
So evidently measuring blocks and such need to be verified, glad I have VAG-Com. Maybe as I have read, I need a parallel mechanical boost regulator? Wish I would have installed a boost gauge before I had the Upsolute chip soldered in. Really, soldered in.
Regardless, more parts are in my future. Oh joy, more parts.
Suggestions/comments accepted gracefully.
1999 New Beetle TDI purchased in, 1999. I am the original owner and It currently has 190,000 miles on it. In 2005 an Upsolute chip was added by Bahn Brenner, the local Upsolute representative. I am in the Cascadian region of the planet.
My spouse is the regular driver, me rarely. Up until this month I had experienced Warp Field Collapse only twice (in 6 years). I really did not think to much about it. I was beating it when it happened.
Now, I find myself driving over the local pass from Western Washington to Eastern Washington on a regular basis. To make this drive you have to go over one big mountain (Stevens Pass) and one smaller one. Now we have repeatable verifable high boost induced limp home mode. And funny, memory serves, the two previous failures were on every large hills while being beaten.
Regardless, I started following the well know and documented repair proceedures to fix the problem.
1. Verified that every inch of the intake system was in proper working order.
The entire intake system was removed and cleaned including the screen, intercooler, and EGR system. The intake manifold was replaced with a new one. The air filter was replaced.
2. I added a McNally boost gauge with EGT read out. The pressure sensor is in the intake manifold just after the EGR valve. I have issues threading holes into plastic as recommend by the manufacturer. (
3. Every inch of vacuum tubing was replaced with properly sized VW factory tubing.
4. Vag-Com testing showed fault with the N75 device. That was replaced
5. The VNT acutator arm was cycled and no binding or rough operation was noted.
6. The VNT vacuum diaphram was tested, works like a charm.
7. For fun the Injectors were replaced because, why not. We had a little more smoke than we like. (The smoke is gone now) (
8. No leakes are dectable in the intake or vacuum system.
Ok, the scary part.
Climbing the pass is obviously a high load event for the engine. I like to pass cars up hill. On the four lane sections you try to at least go the limit. I like to run the cruise control when I can too. Now that I have a boost sensor, I have found that the boost gauge regularly spikes (and the spikes are slow) reads in excess of 25 PSI. Usually the pressure slowiy drops to 14 PSI and no problem other than fear. If I am trying to "maneuver", flooring the throttle when the boost is already that 20+ PSI leads to a rapid jump to 30+ PSI. This pegs the meter and ocassionally after a few long moments, limp home mode. Restarting resets the programing.
When 30 PSI is noted, the EGT spikes to 1,000 degrees F + or - a few.
I am guessing that 30+ PSI is a little steep and that 1,000 deg F EGT is high? WE know limp home is not correct.
Regardless, since the N75 was replaced the VAG-Com tests are not regestering any failures. Also, other than the high load limp home epsides and scary scary high boost readings this car runs like a champ. No smoke, no starting issues, excellent fuel economy, zips around fine. Love the Upsolute chip (I think).
So evidently measuring blocks and such need to be verified, glad I have VAG-Com. Maybe as I have read, I need a parallel mechanical boost regulator? Wish I would have installed a boost gauge before I had the Upsolute chip soldered in. Really, soldered in.
Regardless, more parts are in my future. Oh joy, more parts.
Suggestions/comments accepted gracefully.