Audi A5 2.0 TFSI 2010 B8 feels like it has no turbo

[Aki1981]

hi all

 

sorry if the post is in the wrong place. I bought an audi A5 2010 sportsback 2.0 tfsi recently from auction. After swapping the front end ( radiators bumper and whilst in there the timing chain gaskets). Once back to looking normal-ish i noticed that there is very little acceleration boost. Like the car doesnt have a turbo on it. I have VCDS and did a log of the pressure boost, but i have not got a clue as to interpret it. Before i start throwing money at parts ( PCV, Diverter, N75) if someone could have a look at the graphs ? i should mention that i took the Maf sensor out and the car felt a little better, revving at 6k rpm easier, even in neutral( although i dont know if 4k rmp is a limiter on these audi's and im messing with the engine)

 

Thank you

 

 

boost.CSV

[Aki1981]

Hi Jason

 

thanks for the quick reply. I have taken the logs before disconnecting the MAF Sensor. Would that point to a faulty MAF then?

[Aki1981]

Thank for the quick reply. I just did a test now. With the engine running i plugged the maf out and there was no chNge

quick video attached.

 

i assume i can code the new one with VCDS? 

 

 

[Aki1981]

Thank you!

 

will update with the findings!

[Aki1981]

So I have managed to get to the bottom of the underboost issues. There was indeed an issue with the MAF as well so I have replaced that. The car felt better afterwards but massively underperforming. I have thought to check the Waste gate actuator and when moving it it felt moving freely. So I undertook the task to remove the turbo out entirely to check if any hidden issues and also to check if the turbo is ok. Well, after an insane amount of hours fighting rusty bolts, I have managed to get it out to find....that the turbo waste gate actuator it was off entirely so the wastegate was just flapping about doing noting. I have used an e clip to secure it in place as there was nothing there to hold it. Turbo and wastegate door is in good condition, the impeller and bearing is absolutely fine. The car now performs as it should, making really good boost.

 

However I now have an intermittent fault , "cam 1 actuator cylinder 1 intermittent" but by the looks of the harness wiring loom is understandable ( its busted and frail so will need changing. 

 

Have a look at the pics for everyone that has the same issue.

[Aki1981]

Hi Jason

 

At idle it feels like misfiring, not running smooth, which points to wiring loom or as you said camshaft position sensor. Will have a check on all pins with the probe.

 

Thanks