Beetle TDI won't accelerate. "Brake" engages at approximately 2500 RPM

Hello!
My sister has a 90hp TDI Beetle and is complaining that the engine is being held back from around 2500 rpm, as if the handbrake is engaged. Around 3000 rpm, it then continues 'normally' again. This is especially noticeable in the higher gears, as you quickly pass through this restricted area in gears 1 and 2. This behavior occurs consistently, regardless of whether the engine is cold or warm. Otherwise, it runs completely normally. There's no jerking, smoking, or anything like that. He simply doesn't have any influence in that specific area.

What could it be? A mass airflow sensor (MAF)? A turbocharger? The 90hp TDI doesn't have a variable geometry turbo (VGT), does it? It's a 1999 Beetle.

'Thank you for your help.'

Greetings.

Yes, the 66kW Beetle (the engine code should be ALH) has a variable geometry turbocharger (VTG).


Best regards,
Rudi

Hi,

First, I would connect my laptop and VAG-COM to "the sister's TDI" to diagnose the issue.

Then you almost know everything - and what you can't figure out, we'll .

It's possible that the issue is occurring in the area where the boost pressure is regulated at 2500, and that the VTG (Variable Turbine Geometry) is sticking.

Is she flighty?

You can tell whether a vehicle is a VTG or not by looking at it (or by reading the engine identification letter).

m;

Hello everyone!
What I would do is clear. But the Beetle is 140km away from me, and I think my sister probably can't even find the hood release .
So, I can't look anything up. She's also very likely to be serviced by a male doctor soon. It probably won't work any other way. A ride will clear things up, because he does it all the time anyway.

Does the 90hp TDI engine in the Beetle really have a variable geometry turbocharger (VTG)? So, it could actually be that kind of technology, right? Well, according to what I know, there should still be a warranty .
Is it true that if the rod gets stuck, you'll never be able to fix it so that it stays in place permanently? My 'master' once told me: 'If the VTG is damaged, you need a new loader.'

Greetings.

I would probably emigrate to Mars if there were a fixed VTG.
If the VTG is fixed, there's no point in using Laben anymore.

I've never heard that you can't get them working again.
VW will simply never start cleaning, because they can't offer a guarantee for that.

Are 140 km too far for your little sister? Is my sister doing well?

Only the first 90 horsepower version of the G4 engine had a wastegate (engine code AGR); later, the ALH engine with a variable geometry turbocharger (VTG) was introduced.

If it's still under warranty, contact VW!

m;

Hello!
But wait Maybe there was a misunderstanding. My supervisor didn't say that they couldn't do it, he said that they've done it before, but now they refuse because it's not sustainable. Apparently, you can't verschandeln it in a way that makes it last. And to avoid the hassle with customers, they simply don't do it anymore. That's why the statement: 'VTG is stuck ---> new loader.'
If it's actually the VTG (railcar) and I would have to pay for it myself, I would also verschandeln it myself, if I could see how it's done . Has anyone here done this before? Are there any pictures available?

It's already clear that the issue involves 'VW.' Unfortunately, the dealer where the car was purchased is very far away. For example, if it's the mass airflow sensor (MAF), the trip there simply isn't worth it. That's what it's about. But as I said, she should go to a nearby and have a diagnosis done. Then, you can decide whether or not to make the long trip. When using the loader, definitely .

Thank you all!

Greetings.

96kwtdi wrote:

It's clear that someone is trying to "hype up" the VW. Unfortunately, the dealer where the car was purchased is very far away. If it's, for example, the mass airflow sensor (LMM), then the trip there simply isn't worth it.

You can also have this done by your local VAG service center, and they will then bill the dealer for it. I've had a starter replaced before, too.

Images from VTG.

http://www.technologie-entwicklung.de/Gasturbinen/VNT15-Turbo/vnt15-turbo.html

Thank you for the link! Great website!
One more question: How can you test the ease of movement? Disconnect the vacuum hose from the VTG unit, and then the rod should move freely? How easy is it, actually?

Is it actually not a problem to loosen and then re-tighten the screws on the turbo? Shouldn't they also be tightened with the correct torque? Are there any specifications available for that?

Thank you.

Greetings.

Hello,

It won't become any easier if you detach the hose, as the cylinder has a return spring. Simply try to move the rod against the force of the spring. It shouldn't stick or have any noticeable resistance when adjusting.

But that and much more is actually found here /viewtopic.php?t=2992.

Hi, it's me again!
I had the chance to 'test drive' the Beetle this weekend. But, as luck would have it, he hadn't done it at that particular time .
If this is the issue, then I may have felt a very slight and brief 'hesitation' just before reaching 3000 RPM once or twice. But I don't know the engine *that* well. It can also be normal.
The existing strut, if present, is difficult to test on the Beetle because you can't access it . Perhaps it's the mass airflow sensor (MAF) .

'What I've noticed, and what the Beetle *always* does, is something I find very peculiar and, in my opinion, not normal: The engine starts very reluctantly. You have to let the starter motor run for a very long time, and then it finally kicks in and reaches idle. You definitely have to hold the key in the start position for at least 4 seconds before it revs up. Then it runs normally. However, I don't find this starting behavior normal, especially since we also have an AFN in the family that starts *immediately* when the key is turned to the start position.'
The engine code is ALH.

I am grateful for any advice.

Greetings.

"My car also had similar starting problems, but only when the engine was warm. I cleaned and re-lubricated the starter motor. However, this didn't work for my engine. Then, a new starter motor was installed, and since then, the engine has started perfectly even when warm. The old starter motor wasn't reaching the required speed." You can find a lot of articles on this topic here.

Hello!
Yes, it's still a bit too warm, but it also takes too long to cool down. But based on how it feels, it seems to be spinning fast enough. Although, that could be misleading. I need to look up the relevant posts about this. Does this only affect the ALH model? What does that part cost?

Greetings.

I couldn't hear if the starter motor was missing any rotations. Actually, the old starter motor sounded quite good. Supposedly, the new starter motor should provide a slightly higher RPM than the old one. The starter motor cost about 270 euros from the dealer, but I'll check the invoice again tonight. Maybe you should have the starter motor speed measured. Then you'll know for sure.
And first, let's check all the other possible causes.

Hello!
Regarding the warm start problem:
'A workshop foreman mentioned yesterday that the problem is likely due to the timing belt being set at its 'limit'. I wasn't there, but he was talking about a 'lower limit of 30', and my sister's ALH engine has 32. So, it's technically still within the acceptable range, but it could already be causing starting problems. If adjusting it doesn't help, which he doesn't recommend because it's too expensive, then it could really be the starter motor. I'm not sure what he meant by the number 30.' Possibly the start-up of the pump, or something similar.

Yesterday, the Beetle was taken in for a diagnosis. The main problem was the mass airflow sensor (MAF), but there's a second issue. Apparently, there's a surge in boost pressure, and according to the mechanic, this is due to the difficult-to-move variable turbine geometry (VTG) adjustment. The boost control valve or sensor is supposedly okay. The VTG is still working for now, but it could completely fail in 3 weeks or even 3 years, and the ALH engine could go into 'limp mode.' Those were his words .

Can anyone comment on this and confirm? What would be the best next step? Should I replace the charger myself? Shouldn't that be straightforward? And I don't need to have it calibrated or adjusted through diagnostics, right? Where can you find affordable replacement chargers with a warranty?

'Thank you for your help.'

Greetings.

Oh my goodness... well, I would definitely prefer to adjust the injection timing rather than replace the starter motor.
But the starter motor is much more expensive -> profit margin .

Best regards, Rainer.