Boost Issues 1.9tdi

[B5-PJ]

Hi guys/gals
have a little problem with my diesel, when i get to 3500/4000 rpm in 1st & 5th my car seems to loose all boost, in all gears like its in limp home mode, switch it of and on and it will boost again, been told it may be the boost controller. Anyone else had this issue, common problem and best case fix? thanks in advance

1999 1.9tdi (red i) pre pd engine 2wd

 

[aragorn]

it will be sticking vanes in the turbo's VNT mechanism.

Plenty threads around on the issue, including a popular one about cleaning the turbo with Mr Muscle.

 

[desertstorm]

You need to check the car for fault codes on VCDS and see what it's reporting. could be Underboost caused by a hole in a boost pipe, a duff MAP sensor or several other things.

Karl.

 

[B5-PJ]

You need to check the car for fault codes on VCDS and see what it's reporting. could be Underboost caused by a hole in a boost pipe, a duff MAP sensor or several other things.

Karl.

would it not do it in all gears? someone did say it may be the boost controller

 

[B5-PJ]

it will be sticking vanes in the turbo's VNT mechanism.

Plenty threads around on the issue, including a popular one about cleaning the turbo with Mr Muscle.

would the terraclean egr & turbo cleaner work too??

 

[desertstorm]

There isn't anything that controls boost dependent upon gear. I don't understand how it can only have problems in 1st and 5th gear. You need to check the fault codes and do some data logging. There are many things that can cause these issues. If you clean enough things and change enough stuff eventually you may repair it. What engine code is the car ? .

 

[B5-PJ]

There isn't anything that controls boost dependent upon gear. I don't understand how it can only have problems in 1st and 5th gear. You need to check the fault codes and do some data logging. There are many things that can cause these issues. If you clean enough things and change enough stuff eventually you may repair it. What engine code is the car ? .

pass i know its a pre pd 110 bhp red i

 

[aragorn]

Check all the vacuum pipework for splits, and look online for a guide on checking the VNT actuator. You can try moving it by hand, if its stuck you know thats the issue.

 

[B5-PJ]

Check all the vacuum pipework for splits, and look online for a guide on checking the VNT actuator. You can try moving it by hand, if its stuck you know thats the issue.

i knw i sound stupid but where can i find theses guides as im new to turbos and new to audi

 

[B5-PJ]

Check all the vacuum pipework for splits, and look online for a guide on checking the VNT actuator. You can try moving it by hand, if its stuck you know thats the issue.

i have replaced the vac pipe from the actuator yesterday as i had some vac pipe in the garage, seems to be boosting fine now round to 5k (dont normally use that much) could the old one just be collapsing under pressure ?

 

[aragorn]

possibly, the pipe perishes with age.

 

[B5-PJ]

possibly, the pipe perishes with age.

fingers crossed thats the cure