A6 4F Power Loss Under Load - Troubleshooting

Hi,

2007 4F model with a 2.0 PD TDI engine.

Address 01: Engine Control Module
Label file: DRV\03G-906-016-BRE.clb
Part number SW: 03G 997 012, HW: 03G 906 016 GB.
Part: R4 2.0L EDC G000SG 1348
Revision: --H05--- Serial Number:
Encoding: 0020072

It sometimes noticeably jolts or vibrates under full load on the highway.
Sometimes, it's also noticeable even on country roads.
I would say it gets worse with increasing heat.

Attached is the log of the switching times of the positive displacement pumps (PDs). Based on the switching times and the status messages (status 16 appearing here and there, and status 9), I'm almost inclined to suspect a failing tandem pump. Alternatively, could a leaky seal on one PD affect the others in such a way?

Best, Chris.

Hello Chris,

Is the full power available? A PD cable harness could also be a candidate.

Quote:

Would a leaky sealing ring on a PDE also affect the others in a similar way

Good question - mileage?

Best regards, Rainer.

Okay, I only need to run about 180 kilometers now, which was yesterday.
allegedly only just under 165 km/h, with significantly more potential.
'jerky movement, as experienced during the test drive.'

Mileage: 195,000 km

DPF, intake manifold flap, and EGR valve are not...
Completely new with 15,000 km.

If there's a faulty wiring harness, I would hope to find a corresponding error message.
which hasn't happened yet, but I'm also familiar with other situations like that.
It's designed so that, in the event of a cable fault, it always moves in the positive direction.
with the timing information.

What does a solenoid valve status of 16 mean?

Is that a cylinder head with two PD (piezoelectric injector) elements attached and a conical seat?

Then take a look at the seat.

Quote:

Is that a cylinder head where the PD elements are screwed on twice and have a conical seat? Then take a look at the seat.

Same here, with double fittings --- > PDs are always prime suspects.

I once had a similar issue with a 1.9L 8V engine. In that case, a tensioner bolt was loose, and when the engine was warm, exhaust gases were leaking into the fuel line (at the bottom).

Much simpler than you might think - switch from aftermarket fuel filters to original equipment.
The first one has been replaced and no longer rattles. The other one is half a year old.

If I find the time, I'll run another full-load test.
Let's see where the values are, but you don't really notice.
with the new filter, there are none anymore.

Quote:

Much easier than you might think - switch from an aftermarket fuel filter to an original one. replaces and no longer jerks.

May I ask which manufacturer it was?

We've experienced this issue three times now with what are generally very good male urine filters: a new filter almost completely blocked the flow.

Quote:

With the otherwise very good men's filters, we've had it happen 3 times that a new filter almost let nothing through (!).

... I've never had that before in all these years. The same applies to Mahle/Knecht.

Perhaps it was a victim of plagiarism?

This happened to me once with Elring ZK screws, even though they were purchased from a specialized retailer... I haven't used them again since.

Quote:

Perhaps a victim of plagiarism?

Supplied by our standard suppliers... but we can't completely rule it out.