VW Golf TDi Mk5 - Reduced MPG after replacing turbo on Mk5 Golf TDi

Honest John Back Room » Technical matters
View Threaded
Tue 24 Apr 2012 00:25
VW Golf TDi Mk5 - Reduced MPG after replacing turbo on Mk5 Golf TDi - sunworshipper

Just replaced turbo on Mk5 Golf TDi which seems to have completely changed the power delivery. I was used to a boost (+ boy racer hiss) between 1500-2000 rpm but now also seem to get a secondary boost around 2500-3000 rpm. Whilst this is great (although I rarely use it), I am getting about 10mpg less under careful driving. Used to get up to 70 mpg (according to the notoriously unreliable digital trip), but now struggling to get 60 mpg on the same A road 50 mile commute. Any ideas? Do I need to book it in for diagnostic tests? If so, what am I looking for? Thanks!

Reply | Report as offensive | Link
Tue 24 Apr 2012 07:09
VW Golf TDi Mk5 - Reduced MPG after replacing turbo on Mk5 Golf TDi - madf

I take it you cleaned out the intercooler and all connecting hoses?

Reply | Report as offensive | Link
Wed 25 Apr 2012 15:51
VW Golf TDi Mk5 - Reduced MPG after replacing turbo on Mk5 Golf TDi - sunworshipper
Yes, had
Reply | Report as offensive | Link
Thu 26 Apr 2012 11:01
VW Golf TDi Mk5 - Reduced MPG after replacing turbo on Mk5 Golf TDi - injection doc

Air flow meters on VAG's can cause loss of MPG, may be worth a clean with electrical cleaner

Reply | Report as offensive | Link
Thu 26 Apr 2012 11:45
VW Golf TDi Mk5 - Reduced MPG after replacing turbo on Mk5 Golf TDi - madf

Limp hold mode?

Wrong turbo?

Blocked catalyst with turbo oil....

Reply | Report as offensive | Link