Experiences with Turbocharged Direct Injection (TDI) engines

Hello there,

I've been annoying the search engine lately with queries about turbocharger boost pressure.
They are talking about boost pressure gauges, retrofitting, drilling .... and that's even on new ones.
Cars. I'm really curious now, are the TDI engines sensitive to deviations in boost pressure? Has anyone experienced a significant difference between the actual boost pressure and the pressure measured by the engine control unit? And whose fault was it that the sensor malfunctioned?

Best regards, Manuel.

Manuel V wrote:

I'm really curious now, are the TDI engines so sensitive in terms of deviations from the boost pressure?

Yes!

Quote:

In how many cases did the actual boost pressure deviate from the boost pressure measured by the engine control unit? And whose fault was it that the sensor malfunctioned?

That's not really the point.
It's a quick check without connecting the diagnostic tool.
A jammed VTG mechanism or a hose chewed through by a rodent can be a true disaster. These errors can be quickly diagnosed while driving, without the need for a VAG COM device.

Hello,

Okay, I understand.
I'm still curious to know how often the root cause of the error was due to a faulty boost pressure sensor.

Best regards, Manuel.

barely any...

'But I've used VTG, wastegates, and control valves quite often before.'

And that's why, when troubleshooting, you'll reach the solution much faster with a nice analog LDA (Laser Doppler Anemometer) than with any logs that you have to analyze. The LDA reading in your field of view is easier to interpret than the digital value on your laptop.

CU Gremlin.

Hello,

Okay, I understand.
I'm still curious to know how often the root cause of the error was due to a faulty boost pressure sensor.

Hi Manuel

Essentially, the LDA (Low-Pressure Diesel Adapter) allows you to display the pressure without needing to connect a VAG-COM device. It is quite rare for the pressure sensor itself to be faulty. Therefore, you might as well use VAG-COM.

'Errors on the turbocharger pressure side are often measured by the engine control unit and are usually caused by issues such as a stuck variable geometry turbocharger (VTG), a faulty exhaust gas recirculation (AGR) system, defective control valves, hoses, etc., rather than a faulty sensor itself.'

A mechanical LDA is often preferred by people who don't want to carry around a VAG-COM (including a laptop, possibly a voltage converter, etc.) for every fault (or even just the suspicion of one), or who don't have an adapter, or who like to permanently monitor the pressure (ULF ). However, if you always have a VAG-COM and adapter readily available and don't mind the evaluation process, I don't see any disadvantages to the mechanical version (except perhaps the response time).

Regards,
Private.

EDIT: Gremlin was faster...