Puzzled with my Beetle

Nugget3816

Member
Joined
Feb 6, 2018
Location
Indiana
TDI
02 Beetle 1.9
Okay gentleman here's the question I've got a 2002 Volkswagen New Beetle 1.9 TDI and I don't know if it's a vacuum issue or what it is but I've replaced the actuator and if I disconnect the vacuum line to the actuator the car has no problem revving but when I hook the actuator up I can go to about 3800 RPMs and that's where it'll stop. Now if I leave the actuator disconnected and drive it down the road 1st gear 2nd gear no problem as soon as it hits third it falls on its face if I shut the car off break the vacuum start it back up no problem until I hit 3rd gear and then it falls on its face again can somebody give me an idea what to look for.
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
What is your actual vs. requested boost?

Why did you replace the actuator (I assume you mean the VNT actuator)?

Did you adjust it correctly?
 

maxmoo

Veteran Member
Joined
Jan 19, 2011
Location
Lakefield, Ontario, Canada
TDI
2000 golf, 2001 golf, 2000 beetle, 2003 wagon, 2004 golf, 2004 jetta, all diesels
When you disconect the vacuum line you are overboosting so when your ecu senses this it goes into "limp mode" in order to protect your engine from damage. Turning off the ignition resets limp mode.
Research "limp mode alh tdi" ..... volumes have been written, here and elswhere.
I would start by doing a scan for any codes stored, clearing them, driving the car and then rescanning.
And then report back.
 
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Nugget3816

Member
Joined
Feb 6, 2018
Location
Indiana
TDI
02 Beetle 1.9
I've been working on this thing now for approximately two weeks. The reason I change the actuator is because the old one was all rusted and it was not moving there for it also seized up the actual wastegate. I have drove the car many times and every time the light comes on it's overboost and the mass air flow sensor I have taken the mass airflow sensor off, cleaned it with the mass air flow cleaner, put it back on and it still gives me the same code. The wastegate now moves freely and I have adjusted the actuator both ways and no matter what it's still overboosts every time. I guess my big concern is why is it that first and second gear it will run like a raped ape but as soon as it hits third it goes into limp mode/ falls on his face.
 

maxmoo

Veteran Member
Joined
Jan 19, 2011
Location
Lakefield, Ontario, Canada
TDI
2000 golf, 2001 golf, 2000 beetle, 2003 wagon, 2004 golf, 2004 jetta, all diesels
I've been working on this thing now for approximately two weeks. The reason I change the actuator is because the old one was all rusted and it was not moving there for it also seized up the actual wastegate. I have drove the car many times and every time the light comes on it's overboost and the mass air flow sensor I have taken the mass airflow sensor off, cleaned it with the mass air flow cleaner, put it back on and it still gives me the same code. The wastegate now moves freely and I have adjusted the actuator both ways and no matter what it's still overboosts every time. I guess my big concern is why is it that first and second gear it will run like a raped ape but as soon as it hits third it goes into limp mode/ falls on his face.
I just answered your question above!

MAF's often don't respond to a cleaning on these things...try a new quality one or at least a known good one.....that may well be the cause of your limited rpm.
 

Nugget3816

Member
Joined
Feb 6, 2018
Location
Indiana
TDI
02 Beetle 1.9
Okay change the maf sensor and I still have the exact same problem now it's showing over boost on the turbo so I really haven't changed anything after changing the MAF sensor.
 

Nugget3816

Member
Joined
Feb 6, 2018
Location
Indiana
TDI
02 Beetle 1.9
Okay let me rephrase that I still have my overboosting problem but that's only if I disconnect the vacuum hose if I leave everything hooked up it does not climb over 4000 RPM and it still falls on its face after 3rd gear
 

flee

Veteran Member
Joined
Sep 19, 2011
Location
Chatsworth, CA
TDI
2002 Jetta GLS wagon
Time to get back to basics. See: Diagnosing and Fixing Limp mode for A4 1.9TDI by Canadian_Grizzly
Read through this and follow the information methodically.
With luck you will find the component(s) that are causing limp mode and fix it.
The likely candidates are:
Non-Bosch MAF,
Clogged snow screen,
Plugged intake and/or EGR,
Leaking vacuum pump fitting,
Leaking vacuum hose(s),
Leaking brake booster hose,
Failed or plugged N75 valve,
Improperly adjusted actuator,
Failed or misconnected check valve(s), etc.

You need a vacuum gauge to check most of these.
 
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JB05

Top Post Dawg
Joined
Oct 20, 2005
Location
Il.USA
TDI
Golf,2005,anthracite blue
Could be that the N75 sucked in the residue from the rusted VNT actuator. You can try cleaning it or better yet test it with a vacuum pump. Mine had a lot of contamination from the actuator; so I just replaced that along with the actuator.
 

maxmoo

Veteran Member
Joined
Jan 19, 2011
Location
Lakefield, Ontario, Canada
TDI
2000 golf, 2001 golf, 2000 beetle, 2003 wagon, 2004 golf, 2004 jetta, all diesels
Time to get back to basics. See: Diagnosing and Fixing Limp mode for A4 1.9TDI by Canadian_Grizzly
Read through this and follow the information methodically.

With luck you will find the component(s) that are causing limp mode and fix it.
The likely candidates are:
Non-Bosch MAF,
Clogged snow screen,
Plugged intake and/or EGR,
Leaking vacuum pump fitting,
Leaking vacuum hose(s),
Leaking brake booster hose,
Failed or plugged N75 valve,
Improperly adjusted actuator,
Failed or misconnected check valve(s), etc.

You need a vacuum gauge to check most of these.
http://forums.tdiclub.com/showthread.php?t=179589
 

AndyBees

Top Post Dawg
Joined
May 27, 2003
Location
Southeast Kentucky
TDI
Silver 2003 Jetta TDI, Silver 2000 Jetta TDI (sold), '84 Vanagon with '02 ALH engine
Are you using anything to monitor Turbo Boost? .... VCDS or Scan Gauge! It would be interesting to see the maximum boost.

Also, have you confirmed that the vacuum hose from the Actuator to the N-75 doesn't have a hole in it ... losing vacuum?

At idle, there is full vacuum on the Actuator. Do you know for sure that the Arm on the Turbo is fully down on the set screw when the engine is at idle?
 

Nugget3816

Member
Joined
Feb 6, 2018
Location
Indiana
TDI
02 Beetle 1.9
The arm isn't fully down on the set screw, if I get it to go fully down then it maybe moves about 1/8 of an inch if it's lucky.
 
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