[sh1tbox-alh]

Hello everyone! I´ve got an 01 alh golf that has been having quite a few issues. Today, I´m wanting to figure out why it is overboosting. I´ve got good movement in the actuator arm(starts at 5 and will stop at 18 according to my mighty vac). It will still overboost but only for half of a 1 hour drive. When it doesn't overboost, Ill see about 24 psi and then itll even out to 15 and my exhaust note gets noticeably deeper. Any other time, its hard to not build almost 5-10psi just while cruising in 5th going 75 and all you can hear is turbo noises.. anyone have any ideas?

Normal cruising while overboosting will put me at about 10 psi maintaining 60, but when whatever happens to make it not overboost will having me cruising at 0psi, but also feels as if it builds boost normally as it should when I get on it..

 

[David A. McDow]

You don't mention what resources you used to trouble-shoot your overboost issue. Take a look through this and see if there are systems you haven't looked at: Fixing limp mode low power in a VW Jetta Golf TDI or wagon - feels like lost the turbo boost

 

[sh1tbox-alh]

I wouldn't have come here before reading the overboost sticky. However, I've tried to fix this issue multiple times. While reading that...

 

[David A. McDow]

Connect VCDS and do the N75 test. Check to make sure you vacuum pump is pulling about 30 psi at idle. If the N75 test fails, replace. If you don't have 30 psi isolate vacuum leak.

Edit: post logs for 001-011-004.

 

[sh1tbox-alh]

I’ll see what I can do with vcds lite.

 

[Captainjackson]

My 03 had ongoing limp mode even after replacing all actuators and hoses, and making adjustments to the turbo linkages.

The turbo cam inside the housing that moves the ring to adjust the vanes was badly worn. Bought a used engine with turbo and solved the problem. I mention this in case you've done everything and still stuck.