Fuel consumption and limp mode

[Piet skiet]

Hi guys I recently bought a 1.9tdi jetta 4 overall its a lovely car to drive but I had a issue where we scanned it got some faults after all cleared and nothing came back I'm now seeing a higher fuel consumption as the car idles and heats up it goes to 6.9liters per 100km from 6.3 literally as I watch it climb, also had it go into limp mode turbo not boosting after a certain speed which it hasn't done before what would the most common issue be on this? Thank you in advance

 

[braddies]

19 year old rubber vacuum lines are suspect they get brittle crack and leak, I'd start by checking/replacing the line that runs from the turbo actuator to the N75 valve, maybe replace them all but be careful removing them because the plastic nipples are easy to break

 

[Piet skiet]

19 year old rubber vacuum lines are suspect they get brittle crack and leak, I'd start by checking/replacing the line that runs from the turbo actuator to the N75 valve, maybe replace them all but be careful removing them because the plastic nipples are easy to break

Hi thanks for the reply I replaced all yesterday and still the same though it starts off showing not too bad l/100km as I let it warm up and climbs rather quickly also been seeing some smoke from the exhaust when the car is cold and none when its warm

 

[braddies]

What did you get for codes? Do you have a liter/100kilometer on the instrument cluster?

 

[Piet skiet]

Hi I'm can't remember all the codes some were with turbo boost and rest were for radio and mirrors basically yeah I have the liters per 100km lcd

 

[braddies]

Nice cluster, mine just tells me when the doors are open.
There's a limp mode troubleshooting thread around here somewhere with tons of good info... still looking for the link to that.
if you're getting an under boost code you might try making sure the turbo actuator moves freely (by hand) and with vacuum applied.
A Mityvac is great for measuring vacuum, you can connect it to the vac line right off the vac pump and see what the vac pump is making, should be 25-30hg at the pump. Low vacuum could cause your symptoms but any more info you have could be helpful

 

[Piet skiet]

Nice cluster, mine just tells me when the doors are open.
There's a limp mode troubleshooting thread around here somewhere with tons of good info... still looking for the link to that.
if you're getting an under boost code you might try making sure the turbo actuator moves freely (by hand) and with vacuum applied.
A Mityvac is great for measuring vacuum, you can connect it to the vac line right off the vac pump and see what the vac pump is making, should be 25-30hg at the pump. Low vacuum could cause your symptoms but any more info you have could be helpful

Awsome thank you I'll have a look into the turbo thank you for the help I appreciate it