R5TDI Performance Issues: What Could Be Wrong?

Hello,

Lately, while driving on the highway with no traffic, I've repeatedly noticed that my Touareg isn't reaching its maximum speed.
If I drive it for a certain amount of time, say a few minutes, almost at full throttle, it manages to recover without any problems and maintains the speed.

It's a R5TDI engine, tuned to 204 horsepower, with a manual transmission, and WITHOUT a DPF (Diesel Particulate Filter).

It performs well up to 180 km/h, but it absolutely tops out at 190 km/h.
Even with the slightest incline, his speed drops to 150-160 km/h.

According to the oil temperature gauge, it was then between 100-120 degrees.

After driving for a few minutes with almost full throttle, you'll notice a slight increase in power, and it will continue to accelerate until reaching 210-215 km/h. On inclines, the speed only drops to a minimum of 195 km/h.
The oil temperature will then reach 120 degrees and remain at that level.
From that point on, I won't have to drive almost full throttle anymore.

I already checked the error memory, but of course, there's nothing stored in it.
Otherwise, the car runs perfectly fine.

The problem is that the R5 TDI starts to make a very loud, droning noise in the speed range between 160 km/h and 195 km/h. Then I either drive below 160 km/h or, if the road allows it, I sometimes go up to 200 km/h.

What do you think about it?

Is there anywhere I can even start looking?

He probably burned some oil soot for a while, which completely clogged the intake manifold (see another thread).
Could the cat have gotten into that?

Greetings and thank you.
Marcus.

Measurement blocks 3.8 and 11 at full throttle?

Best regards, Rainer.

Hello Rainer,

I'll take a look at it this weekend.
Thank you.

Greetings.
Marcus.

Hello,

Okay, I just took a trip and recorded some data.
Take a look at this.

I have created two log files because I have observed another phenomenon since Saturday that is quite concerning to me.
When the engine is cold, you can repeatedly hear a rumbling and knocking sound. This happens especially when I briefly give it a little gas while the car is stationary, and the engine speed then drops back to idle.

Even after I turn off the engine, I can still hear and feel a creaking and banging sound when I turn the steering wheel. It sounds quite bad from the outside.

What could this possibly be now?

- Engine mount?
- Dual-mass flywheel?

This issue occurs as long as the engine hasn't reached its operating temperature, and then it only happens at idle or when the clutch is disengaged and the engine speed drops to idle.
However, there is no noticeable 'sawing' or similar noise when the engine is idling.

Can I test the hydro-motor bearings in any way (e.g., using actuator diagnostics)?

Okay, log files like this:

......hit.csv = idle problem.
... Leistung.csv = End speed problem.

Sure, here's the translation:

'Thank you.'
Greetings.
Marcus.

Does your car reach its maximum speed at 3380 rpm? No? Then what's the point of investigating a problem with a missing maximum speed in such a log?

Hello Rainer,

Oops, I misunderstood that.
I thought I was only supposed to drive at full throttle once, but not on the highway at the maximum speed.

Okay, hopefully I'll manage to do that sometime this week.

What do you think about my idling problem with the squealing and rumbling?

Is there a way to test the functionality of the hydro-mounts?
They're somehow electronically controlled, aren't they?

Greetings.
Marcus.