Overboost/limp home

[tonyholbury]

I had a problem when my 2007 1.9tdi Touran went into limp home mode.

The tester said OVERBOOST

Crawled under car and pulled on the Turbo boost arm and it was free so not jammed by soot.

Bought a second hand vacuum control box, (NOT the N75 as stated in some you tube videos

Removed battery for access

To remove box undo four torx screws, then slip off two clips on the hose plug end, finally unclip the control electric plug, reverse procedure to refit.

Only pain in the backside was the torx screwsm, you cannot see all of them and you need something like a 1/4 drive with a short extension to get in their and apply enough pressure to undo them, mine were tight.

As a belt and braces man I also replaced the mAF sensor you need a 5 point security torx to undo these WHY SECURITY SCREWS????

Anyhow all done and after warmup engine will now, rev beyond 3000rpm, all fixed.

One question

This car is supposed to do mid fourties MPG

Only Does 36 which is crap compared to my last diesel a KIA Carens which would do 42+

PS put this in the newbie section as I believe over boost is a fairly common problem with all VWs with variable vane Turbos

PPS use a can of EGR/Turbo cleaner once or twice a year, most of them get jammed by soot build up

PPPS anyone want a brand new N75 valve??

[Volkswagen Owners Club]

Thanks for the detailed write up Tony and also great to hear you have fixed the issue successfully!

Not sure about the MPG, maybe it will improve over time once the engine settles down after the issue ?