A4 Turbo, no boost

[abbsy3]

Hi, I used to have a TT, and you could hear and feel it when the Turbo kicked in. I have just bought a A4 1.8T (2003) Engine code BFB, and does not seem to have any boost. There are no codes recorded, and not indicating it is in limp mode. Would appreciate a few pointers to look at please.
Would have expected a ECU error code if the turbo is not working. I have not changed any parts yet, but hope the turbo has not gone!
No abnormal smoke from the exhaust.

Any thoughts would be much appreciated!

Thanks!

[nickeym1]

Im certainly no expert mate but a wire came loose on my map sensor and there was no boost. I also took a few things out to clean before and put a pipe back in the wrong place and no boost. Have you done anything with the car lately

[abbsy3]

Hi,

Thanks for the reply!
The only thing I have done is replace the coolant flange, but dont think the boost was there before I did that. Is it your MAF sensor that had the loose wire? I have also plugged into the ECU for error codes, and there are non?
Not sure if you can see the live boost pressure, or do some test to see what it is?
I will make a start as you say and check the pipes and connections to the Turbo, and see if anyone else has had a similar problem to you, but will check the sensor. Thanks for your help!

[nickeym1]

Hi,

Thanks for the reply!
The only thing I have done is replace the coolant flange, but dont think the boost was there before I did that. Is it your MAF sensor that had the loose wire? I have also plugged into the ECU for error codes, and there are non?
Not sure if you can see the live boost pressure, or do some test to see what it is?
I will make a start as you say and check the pipes and connections to the Turbo, and see if anyone else has had a similar problem to you, but will check the sensor. Thanks for your help!

No it was a loose wire on the map pressure sensor worth a look anyway

[dannyboy11]

Could be a sticking actuator arm keeping the wastegate open, that would allow all the boost to escape.

[burkey1]

You can test the turbo if you have VAGCOM or VCDS.
you need to map some variables on VAG Scope.

Below link should be helpful.

https://www.vwaudiforum.co.uk/forum/s...d.php?t=105813