Tdi issues

Rishav

Member
Joined
Oct 27, 2019
Location
South africa
TDI
Polo 1.9tdi 96 kws
Hi guys
Need help please or I’m going to get grey with this TDI, I drive a polo 1.9 tdi, 2007 model 9n3 sport line 96 kw model 6 speed . I recently while pulling a trailer found the car just lost total power I just managed to get home , next day I used Ross tech vcds and found the car came up with the fault underboost , so checked and did a DTC clear took the car for a drive same story , if you on the 6th gear and you put foot down under 1500 rpm the car just starts dropping speed you change down and get to 4th and foot down the car starts picking up speed and then a lag again by like 2300 rpm , got back home and checked again zero fauts , checked egr valve cleaned, vacuum pipes and even pulled out Maf sensor still the same driving the car daily but it’s like a donkey , I checked for leaks but nothing at all ,I did log the car using vcds, I will attach it soon to this post , thank you in advance to anyone that would kindly assist me
Thank you
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
It's possible the in-tank pump is getting weak or it's done and is wearing out the tandem pump.
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
So did this just come about after you pulled the trailer? If the ECU sees any of several conditions it will revert to limp mode, not allowing the turbo to fully engage for high end power. Other than the lack of fueling, it's also possible one of the big hoses popped loose.
 

Rishav

Member
Joined
Oct 27, 2019
Location
South africa
TDI
Polo 1.9tdi 96 kws
So did this just come about after you pulled the trailer? If the ECU sees any of several conditions it will revert to limp mode, not allowing the turbo to fully engage for high end power. Other than the lack of fueling, it's also possible one of the big hoses popped loose.


I have recently serviced the car , fuel filter done 1000 kms on it could it be the fuel filter restricting it ..


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Rishav

Member
Joined
Oct 27, 2019
Location
South africa
TDI
Polo 1.9tdi 96 kws
So did this just come about after you pulled the trailer? If the ECU sees any of several conditions it will revert to limp mode, not allowing the turbo to fully engage for high end power. Other than the lack of fueling, it's also possible one of the big hoses popped loose.


Yes sir only after I pulled the trailer I felt it , checked the hoses seems fine no whistling noise either


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