Toledo 1M: Turbo Problems & Repair Guide

Hello everyone,

I'm a new member as of today, so hello everyone.

I drive a 1999 Seat Toledo 1M with the original AHF engine and no modifications (81 kW). The odometer currently shows 218,000 kilometers, which have been driven without any problems so far.
"Recently, I've been experiencing issues with full load capacity, which manifest as a loss of power. Let me try to explain:"
The engine is running normally. Exception: prolonged full-throttle acceleration in the 4th or 5th gear. After a few seconds, it enters a limp mode. The error code stored is: "Boost pressure exceeds regulation limit." Based on my research of relevant technical articles (which I found very informative and interesting), I suspect what's called a "VTG hot-clamping" issue.
What has already been checked:
-LMM- OK (Tested with demonstrably functional LMM).
- The VTG control system appears to be functioning correctly (magnetic valves were tested by being temporarily replaced), but no change was observed.
- VTG movable between the stops.
- Hoses in good condition.

The problem usually doesn't occur when the engine is at its operating temperature; sometimes I can accelerate to, for example, 185 km/h a few times. However, on the next attempt, it often cuts out around 120-140 km/h, then goes into limp mode with reduced power.

I have the option of performing a log drive using VAG-COM.

Who can and wants to help me troubleshoot this issue? What data should I log? And what else can I check? Have I forgotten or overlooked anything?

Thank you in advance.

Greetings.
Todde.

Thank you for the renaming and the tip about the reading material for new users (which I have already read), and sorry for the mistake I still made .

Since I didn't want to immediately make any mistakes or annoy the experts here with unnecessary data, the core of my question is:

What information should I provide if someone wants to help me solve my problem? My goal is, of course, to narrow down the cause as much as possible in order to avoid replacing unnecessary parts.

Greetings.
Todde.

Hi,

Please check if the vacuum sensor is always working properly, or if the spring inside might be broken. If the spring is broken, it might only cause problems intermittently.

Best regards, Rainer.

Rainer K. wrote:

Hi, Please check if the vacuum sensor is always working properly, or if the spring inside might be broken. If the spring is broken, it can sometimes cause intermittent problems. Best regards, Rainer

Hello Rainer,

Okay, thanks for the tip, I'll check it out.

Ich habe bereits eine erste Logfahrt gemacht, bei der der Fehler auftrat (im 4. Sure, here is the translation of the text from German to English:

"Gang."

click

This was actually just for testing the diagnostic process itself. Can you tell anything from this? According to the technical data, the boost pressure at full load should be: 1950 mbar, but it is: 2250 mbar. As I interpret the log, the boost pressure seems to be within range (or perhaps exceeded? please correct me if necessary). Or could it be that the pressure sensor itself is malfunctioning and providing incorrect values to the engine control unit (ECU)?


Greetings.
Todde.

Hi,

Yes, you can see something is wrong. The vertical travel gauge (VTG) definitely isn't moving far enough – are the lever stops okay?

Best regards, Rainer.

Okay, I will investigate this further and let you know the results.

Thank you and best regards.

Todde.

Hello,

I did some homework, but unfortunately without success.

- Vacuum sensor for the turbocharger was removed and checked -> OK.
- For a remotely located valve: The VTG adjustment is surprisingly easy to move from stop to stop.
- After an induced error during another measurement run (the engine is still in emergency mode at idle), the canister/VTG is at its upper limit (open), which is normally completely down (closed) in idle mode.

What I still want to do:
- Install a boost pressure gauge to compare with the sensor readings.
Could the boost pressure sensor itself be the cause by providing incorrect readings? That's why I had the idea of using a lambda probe (LDA) for comparison.
On the other hand, when the engine is running, the values from both sensors are consistent with each other.

Is there anything else I can do?

Greetings.
Todde.

Good day.

Here are three more logs. Can we rule out a VTG hot clamp here? As mentioned before, everything is very easy to operate when it's cold.

Please take a look.
click

Greetings.
Todde.

In my opinion, it looks like a stuck turbocharger! -- Remove the turbo and verschandeln the variable geometry turbine (VGT)!

Toledo1M wrote:

Here are 3 more logs. Can we rule out a VTG hot clamp here? As mentioned before, everything is very smooth when cold.

I agree with T3-Surfer.

By the way, this is quite a nice documentary about hot air ballooning – even if it doesn't help you much.
Perhaps you can avoid having to disassemble and verschandeln the VTG by using the "blinker trick" (see FA about stuck VTGs), if you work the VTG long enough while the engine is running.


BTW.
The most sophisticated alternative is to modify the software parameters for the basic settings of the MWB 11 system (chip tuning).
Set the speed to 900 (if it is originally set to 1400), change the maximum speed limit from 1500 to a maximum of 2000 rpm, and reduce the pulse duration from 10 seconds to approximately 0.5 seconds.
This is a nice VTG cleaning tool that can be activated and run for as long as needed via diagnostics*), without having to operate with constant flashing lights, which makes it very effective thanks to the fast switching sequence, and it's also almost foolproof if the shutdown speed is programmed correctly.
Only the extremely rapid acceleration when the train is moving and at full throttle requires some getting used to .
For the standard basic configuration function, it is temporarily necessary to switch to a different encoding.

*) as long as the cut-off speed is not exceeded; otherwise, even with a short pulse width, the load density (LD) can become too high at full load, and this critical speed depends on the type of charger and the fuel injection curve at full throttle.

Hi T3 surfers and Ulf,

Thank you for your confirming opinion. We will proceed with the disassembly and cleaning. To do this, I will study the technical documentation and purchase some seals. Before that, we want to perform the Bowden cable test, which should definitively diagnose the suspected "hot sticking" issue. I'm hesitant to make any changes to the software, although it's an interesting option worth considering. Thank you for pointing out this possibility.
The cleaning will have to wait a little longer; I still need to drive approximately 1000 km next week in this condition }. (I will consciously avoid driving with full load for extended periods }).

I will definitely document the cleaning process and share the results here.

Thank you and best regards.

Todde.

Toledo1M wrote:

I will definitely document the cleaning process and share the results here.

Very good, please send it over.


ULF:

Quote:

This is a nice VTG cleaning tool that can be activated via diagnostics at any time and run for as long as needed*), without having to constantly flash, which makes it very effective thanks to the fast shifting sequence, and it's also almost foolproof if the shutdown speed is programmed correctly.

Very insane, cool idea! Where can I find this awesome cleaning tool?
I could comfortably verschandeln the VTG once a month without wasting any unnecessary kerosene through pointless 0-1-0-1 gas engine shenanigans:

T3Surfer wrote:

ULF: Quote: That's a nice VTG cleaning tool, Very insane, cool idea! Where can I find this awesome cleaning tool?

At every chip tuner who really knows their way around the software.

Here's the promised "report" with problem-solving solutions:

Turbocharger (VTG) appears to be functioning correctly, but the pressure sensor on the intercooler is defective.
As a last resort before expanding the charging system, I decided to replace the sensor to rule it out as a source of error. And sure enough, after installing the new one, the tractor is running again. So, the sensor was indeed providing incorrect values that seemed to clearly indicate a VTG malfunction. Or, perhaps the new sensor provides different values that don't cause the emergency mode. Regardless, the cleaning process will have to wait.
A dyno test confirmed everything. The boost pressure curve followed the set parameters very quickly, unlike what was described previously.

Lucky you .
Unfortunately, the documentary about a VTG cleaning process won't be happening for now.


Greetings.
Todde.

Congratulations on finding the error; I wouldn't have thought it was related to the laser diode sensor! It seems like a very rare issue.

Hopefully, the VTG will continue to serve its purpose.

Okay, let's see if things are quiet now. On the test drive (on the highway, I have a section here without a speed limit), despite repeated acceleration in 5th gear, the old problem couldn't be reproduced. Just yesterday, the tractor was running terribly, which motivated me to intervene today. At around 120 km/h, it went into limp mode again. With the new sensor, I reached 190 km/h according to the navigation system for the first time in half a year.