Need urgent help... Loss of power...

Please help me...

I've been driving a Lupo 3L for a week, and I've experienced extreme power loss. The mass airflow sensor was replaced, but it didn't really help or only made a very small difference.

There's no noticeable difference whether I switch to 45 horsepower or 61 horsepower, except that it revs higher.

I estimate that it currently has a power output of around 35-40 horsepower.

Regards,

Tom.

Hello,

Have you had the error memory read out? Can you...?
Did you find an error here?
That would make the analysis much easier.

Bye.

Michael II.

'The error memory was read. There was an error code stored (but please don't ask me which one). It was then reset, and since then no errors have appeared in the memory. However, there is still a significant loss of power, especially at higher RPMs.'

Tom.

Hello,

Did you have the error memory read out immediately after the repair, or only recently?

'The workshop read the error memory before the repair. After the repair/test drive, an error was present. The error memory was reset, but there is still a loss of power.'

Tom.

... have it read out again at another workshop, and ideally printed out!
Be careful that nothing gets pushed aside again.

I just called my mechanic's shop. The error in the system was/might be: 'Intake manifold pressure too low.'

Regards,

Tom.

Sure, here's the translation:

'P.S. Could it be that the small black lever in the fuel filler neck has something to do with it? I accidentally pressed it while refueling. Coincidence or not, since then it's only been running at 'half' power.'

The small lever in the fuel filler neck is the vent to the expansion tank. It shouldn't have anything to do with a loss of power. If you press the lever while refueling, a significant amount more fuel will go into the tank because the expansion tank is also being filled (very slowly). In my Golf, it's about 7 liters, in my Lupo it's about 5 liters, and in a VW bus it's about 11 liters.
You should be careful in warm weather, as that's what the expansion tank is for. If it's already full, the tank will overflow.

Best regards, Bertil.

Hello,

There are essentially only two possibilities with your control unit that indicate "intake manifold pressure":

1. Manifold pressure sensor G71 is defective or providing an implausible signal.
Solution: Check the power supply and wiring.
(Error numbers: 17563, 17564, 17565)

2. Charge pressure regulation differential.
Solution: Faulty N75 valve (boost pressure control valve).
Leaks between the turbocharger and the engine (charge air pipe).
Turbo failure.
(Error number: 17958)

Sure, here is the translation of the text from German to English:

"Note:"
Based on the description above, I wouldn't even trust this workshop to repair my daughter's scooter!

@Michael II

Thanks for the reply, I'll take a look or pass the tip on to my mechanic.

'Hey, are you a VW mechanic, or where do you get all those error codes from?'

Regards,

Tom.

P.S. I sent her an email to your GMX address; you can read it if you're interested.

A reputable workshop will tell you what the problem is or provide you with a written diagnosis; this is standard practice even in Spain! Of course, this won't happen if someone approaches it with the attitude: "Just get the car running, I don't care how, but if it doesn't work, I'll sue you."

Regards,

Olaf.

Since you seem to have some experience with the control unit, I might as well ask you a quick question:
"Intermittent error: 'Boost pressure below minimum threshold'." Besides the N75 valve, EGR system, and VTG mechanism, what other potential sources of this problem do you think could be responsible?

Regards,
Olaf.

P.S.
"I have a 1.4 TDI PD engine, but it probably won't make much of a difference..."

Thanks to everyone who gave me advice... the problem has been resolved.
Since my workshop told me they couldn't fix the mass airflow sensor for another week (the earliest possible appointment), I took a look at it myself (thanks to your tips)...

Okay, so after I removed the engine cover, I immediately noticed the defective hose leading to the pressure sensor of the variable turbine geometry (VTG). I sealed the hose with tape (I didn't have a replacement hose available)... Test drive... And there it was, full power again.

A big shout-out to the friendly, hardworking, and above all, competent mechanics/master technicians (mostly trainees) at the Volkswagen dealership workshop who checked the system and adjusted the mass airflow sensor (MAF).

THX.

Tom.

..... from my Golf III TDI Variant (90 hp).
Ich hatte den, ach so berühmten Fehler 0575 - Regeldifferenz Saugrohrdruck in meinem Fehlerspeicher. Also ab mit dem Auto in eine VW-Werkstatt, da mir weder ATU noch Bosch behilflich sein konnten. Dort wurden allerhand Tests durchgeführt, Gesamtkosten Euro 147,80. Ausgetauscht wurde ein , angeblich defektes Relais. Ergebnis: gleich Null, der Fehler trat immer noch auf. Also im WWW nach einer guten Seite gesucht, und hier gefunden.
I was browsing through the archives and discovered that many more Volkswagen drivers and owners are struggling with this problem. So, I started investigating the issue myself. And what can I say...

.... I found the error immediately. The VW idiots (sorry for the crude language) had pinched a hose inside the air filter housing (from the small valve on the body...). I freed the hose, and now my Golf is free again. It's running smoothly and pulling like it used to ..........