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Top speed: 170 km/h?? Why?

 
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SirBiBi
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Post02-05-2002, 13:16    Subject: Top speed: 170 km/h?? Why? Quote

Hello,

I have a 1.9L Passat TDI with 66 kW, manufactured in 1998.

How can it be that the car can only reach a top speed of 170 km/h?
Around 150 km/h / approximately 3200 rpm, I get the impression that the car...
exhibits minor performance fluctuations.
(hopefully, no one will notice but me while I'm driving) icon_confused.gif

It's a bit annoying when my sister, driving her Octavia (same model), just drives past me. icon_mad.gif

Best, Björn.
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Chris
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Post02-05-2002, 14:56    Subject: Top speed: 170 km/h?? Why? Quote

hi,

One possible source of error could certainly be a faulty mass airflow sensor (MAF). You should try swapping the MAF sensor from your sister's car into your Passat and see if it improves the situation! I'm currently experiencing the same problem with my Golf AHF 110 hp TDI – it can only reach 180 km/h on the highway. However, it's pretty much confirmed that the issue is with the MAF sensor.

Best regards, Chris.
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SirBiBi
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Post02-05-2002, 15:15    Subject: Top speed: 170 km/h?? Why? Quote

Hi Chris,

I'd rather not do that test-related renovation. icon_confused.gif My sister would kill me.
How much would it cost to buy a new mass airflow sensor?

Hi Björn,
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nellor
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Post02-05-2002, 15:16    Subject: Top speed: 170 km/h?? Why? Quote

I also suspect it's the LMM (low-mileage module) because I experienced the exact same issue.
Volkswagen Golf IV, 1.9 TDI, 90 horsepower.
The car easily reached 190 km/h, but after the mass airflow sensor started malfunctioning, it could only manage around 170 km/h (and that was pushing it).
The part was replaced, and now it's running at 190 [units - e.g., km/h, mph] again.

Manuel.
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SirBiBi
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Post02-05-2002, 15:30    Subject: Top speed: 170 km/h?? Why? Quote

Hi everyone,

If the error is actually due to the LMM, are there any other options?
Are there any other signs of that?

Think about increased consumption or loss of performance.
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dieselschrauber
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Post02-05-2002, 15:38    Subject: Test of LMM conversion/upgrade Quote

Hello,

You should treat your sister to an ice cream sometime. icon_wink.gif
The "test disassembly" involves only removing two cross-head screws, a spring clip, and a connector.
Cost of a new language model: several hundred euros.

The actual working time for a test reconfiguration should be around 5 minutes if you take your time.

The mass airflow sensor (MAF) reduces the maximum possible fuel injection amount when the measured air mass is too low, in order to prevent soot formation. This results in a loss of power, even though enough air is being drawn in.

Best regards, Rainer.


Last edited on 02-05-2002, 16:00, edited 1 time in total.
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mrblue2000
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Post02-05-2002, 15:57    Subject: Re: Test of Mass Air Flow Sensor (MAF Sensor) Replacement Quote

Hello,
Cost of a new language model: several hundred euros.


More specifically, €250,-, which I just confirmed with VW today, because mine seems to be broken as well.

hello
I'm sorry, I can't translate that word. It's not a word I recognize.
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ulf
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Post02-05-2002, 16:22    Subject: Signs of a faulty mass airflow sensor Quote

SirBiBi wrote:
If the error is actually due to the LMM, are there any other signs of this?
think about increased consumption or loss of power.


Does the loss of performance not icon_wink.gif suffice?

There is generally no increase in fuel consumption, as the injection amount is reduced accordingly to compensate for the "apparent" lack of air.
Sometimes, fluctuations in acceleration may occur.

Before replacing the relatively expensive part, I think it's worth trying to verschandeln it with brake cleaner spray. If the thing is only dirty, you can get a "working" LMM and full performance again with minimal financial investment.
Gruß Ulf
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MG4 Electric
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JET
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Post02-05-2002, 19:00    Subject: Top speed: 170 km/h?? Why? Quote

Hello, I had a new mass airflow sensor (MAF sensor) installed a week ago. It would have cost 267.30 euros, plus 67 euros for installation, error code reading, etc. But luckily, VW covered 70% of the cost as a gesture of goodwill.
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SirBiBi
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Post02-05-2002, 20:32    Subject: Top speed: 170 km/h?? Why? Quote

But fortunately, VW covered 70% of the cost out of goodwill.

How did you justify that with VW? Can I make a difference if I complain that my car has such a problem after only 3 years?
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SirBiBi
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Post03-05-2002, 12:24    Subject: Top speed: 170 km/h?? Why? Quote

Hi,

Fixing things isn't always easy with a mass flow meter.
I cleaned the metal surfaces and then took it for a test drive.
I somehow get the impression that it has actually gotten worse.
Then I probably really need to buy my sister an ice cream sometime. icon_wink.gif
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DerAlex
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Post03-05-2002, 12:47    Subject: Top speed: 170 km/h?? Why? Quote

'Just quickly cleaning the metal surfaces.'
You might have just pushed him over the edge. You have to be extremely careful when handling this part.

I used about half a can of brake cleaner (a 500ml can of LiquiMoly, costing around 4 or 5 euros), and after that, the car noticeably ran better.
I just sprayed the cleaner on and let it dry, that's all. Mostly, I didn't touch anything (meaning I didn't wipe or scrub at it with the cloth or brush).

Good luck.
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Post03-05-2002, 13:16    Subject: Top speed: 170 km/h?? Why? Quote

Hi SirBibi!

The rules regarding goodwill are clearly defined. I only know the conditions for Audi. In general, for vehicles that are 3 years old, goodwill may be granted for defects that are not the customer's fault (Audi offers 50%, VW offers less). You don't need to be overly aggressive; a goodwill arrangement will likely work out anyway. I also had a faulty mass airflow sensor (MAF) and experienced the same symptoms as you.

Best regards,
Uwe
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