Loss of Power

[Steve24]

I have a late 2018 Audi A7 3.0 TDI BiTurbo with 24k on the clock.

My problem is that it felt pretty flat, even though the car performs fine and there are no lights on the dash, it has been serviced at every service interval and has always passed the MOT without and issues.

So I had it tested on a dyno and instead of getting close to its 320 HP, it only gave 235 HP and the torque was well down, the guy who tested it said that the acceleration was poor and that it felt a little rough at the top end and thought the most likely cause was that the sequential turbo wasn't working correctly and suggested I get a boost gauge fitted to see what was happening.

I'm no expert on these things, but to lose so much power even though the car performs ok something must be wrong

Has anyone ever seen this problem before and could the problem be with the turbo

 

Any help would be much appreciated.

Audi A7 Dyno Result.pdf

[Steve Q]

Well done for having it Dyno tested, your suspicions were founded. My next recommendation would be to have a diagnostic check to see if any fault codes flag up. 

The tester could be right regarding the turbo. But it could also be the turbo pipes. Is there any whistling from the engine bay? 

[Steviebobs]

Hi, I have a similar problem with loss of power. It started 29/08/24, the car drives fine but is in limp mode with the coil flashing. There hasn't been s DPF warning light although 3 mechanics including Audi, say the DPF is blocked, £800 for Audi to tell me that. Audi said it needs a new DPF (£3500). The problem I have is how long would a car run normally with a blocked DPF, by the end of this month it will be 4 months and as I said, everything works as it always has. fine. My Q5 is 2011 3.0 and has only done 85000 miles. anyone out there had the same problem?  Many thanks in advance.

[Steve24]

I can't hear any obvious whistling noises coming from the engine bay, but a leak would certainly not help, but I can't help feeling that to lose 80 HP it has to be to do with the turbo.

Is there any way to test the turbo ?

Something else the guy who dyno tested the car said was that it was a stock map apart from the Adblue had been mapped out, which I had done on Audi's recommendation as the Adblue system had failed.

The DPF was mapped out when I purchased the car and I'm guessing this was done as the DPF has been knocked through and there is little back pressure, which should actually increase the performance.