"Blow by" Gase mit VAG-COM messen? | Posts 16+

Hello to everyone participating in this issue.
Of course, there are several ways to measure 'Blow by - Gases', with the volume being the most interesting measurement, rather than the pressure. If these gases are essentially 'exhaust' from the turbocharger's intake air mass, their mass can be measured using appropriate software by tapping or plugging the KWG ventilation hose, along with the values from the MAF sensor. In this way, the exhaust gas recirculation itself is also monitored. However, these values do not provide information about whether they are the cause of the missing km/h. I have been working with diesel vehicles at a Bosch service for over ten years, and it would be the first vehicle where I have identified a lack of compression based on the measurement of 'blow-by gases,' and furthermore, that the consequences are not seen in poor cold start performance but in a lack of engine power. My personal opinion on this issue is that the problem is being looked for in the wrong place. The standard troubleshooting process should begin on a dynamometer to accurately determine which RPM ranges the engine is experiencing a lack of power, and then one can truly consider the cause. However, I also do not want to completely rule out the LMM, because depending on the condition of this HFM 5, different error patterns can result from it.
So, as I said, don't waste time measuring 'blow-by gases' or anything, but rather look for the right errors...
Best regards - Rumpi