Gray smoke under full load

Hello,

I need a tip. Audi A6, Model 00, V6 TDI AKN. Automatic transmission.
At full load in 5th gear at approximately 170 km/h, a loss of power and severe vibrations.

In the lower gears, it drives normally, has full power, and doesn't smoke.
Up to 170, everything is normal, then it suddenly collapses.

No error storage entry.

Maybe someone has experienced something similar before...

Thank you in advance for all the answers.

Best regards, David

Hi David,

If you can clearly distinguish the gray smoke and not blue or white, then I can only think of one thing with similar symptoms.

When my DiFi was running very low on fuel, I experienced a significant performance drop and saw grey smoke coming from the exhaust while driving at high speed (over 150 km/h) and under full load. After reducing the speed, the problem disappeared. Then full throttle again, and after 150, it starts to jerk and produce grey smoke clouds.
Parked in the parking lot and checked for clear lines with the engine running. I observed larger air bubbles in the diesel line. I just filled it up completely so that the vacuum pressure would be lower, and then I was able to drive smoothly, even at over 150!

Therefore, I suspect that the problem with your symptoms is due to air in the sprinkler line. Have you checked?

Best regards, Georg

And check your own
Air filter. Has it gotten wet?

It could be that the "defect" is...
at high air flow, upwards
Okay. That gives your engine
then there isn't enough air. At
Reduced intake of air
Does it work in reverse?

Had I already been here twice?
in the workshop.

Found the error. It was too high crankcase pressure. New valve, everything is okay.