TSI squeal noise problem on acceleration

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Originally Posted by Tommy

Interestingly, I followed a brand new 118TSI down the freeway on Saturday as it belched black smoke under acceleration and squirted out a large amount of fluid out of both exhaust pipes. This does not look normal at all, nor does it look very 'appealing'... Should a brand new petrol car be doign this sort of thing?

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Most turbo cars produce a plume of dark exhaust when given full throttle. The ecu runs the mixture rich to prevent detonation etc.

The problem (squeal noise) hasn't been fixed yet, right?

My car hit 2500k's over night, and today I noticed the supercharger became a lot louder now, never used to be audiable from inside the car, only in car parks with the windows open lol.

I also noticed the aqueek noise from the S/C clutch today for the first time, could these two thing be part of the one thing?

Could they possibly be a little cut back for the first 2500k's and then after it spins harder, which makes the clutch engage more audiable also?

just a thought....

Stoney!

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Originally Posted by logger

Fair enough. You don't have the time to be stuffing around with the trivia when you have things that need fixing and established methods to do so, that work.
I have been doing some research and there is a certain amount missing from the Ross-Tech label files and what they know of the twincharger. But with a little bit of strategic fiddling I have managed to identify a couple blocks that are useful but were previously unknown to them. So far I have found G583 which is supercharger OUT manifold pressure and today I am fairly certain I found G584 which is the regulating flap position. Controlling Air into the supercharger. Its noisy little bugger by the way. Have not found the PWM yet, but will keep looking.

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Have you looked at MVB 00 that is the running numbers that the ECU see's. It does most of its calculations based on the those numbers. Those numbers are a direct feed from different sensors on the motor. I would almost bet you would see one of those change as the PWM was changed. I am not sure as to how long the delay would be from when it happend to when it would show up on there though. MVB 00 is how we can see if the fault memmory has been changed in the few days before a car come in with a problem. When the fault memmory is cleared I think 7 or those numbers will reset to 128 untill all of the basic settings have all been set (The Readiness code of the car).
Just something you could look at.

FYI, my MkV TSI has just hit 32K and I haven't noticed this chirp for a long time, probably the last 3 months or so (approx 4000km).
As stated previously it never really bothered me so didn't realise for a long time that the noise wasn't present.
Nothing else other than the fact that it may not be a permanent "feature" :crazy2:

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Originally Posted by v.w.dave

Have you looked at MVB 00 that is the running numbers that the ECU see's. It does most of its calculations based on the those numbers. Those numbers are a direct feed from different sensors on the motor. I would almost bet you would see one of those change as the PWM was changed. I am not sure as to how long the delay would be from when it happend to when it would show up on there though. MVB 00 is how we can see if the fault memmory has been changed in the few days before a car come in with a problem. When the fault memmory is cleared I think 7 or those numbers will reset to 128 untill all of the basic settings have all been set (The Readiness code of the car).
Just something you could look at.

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I don't think I can get MVB 00 with VagCom, if by that you mean measuring block 00 as in zero. VAGCom has measuring block 001 through 253 with four fields in each. But perhaps your 00 is the same as my 001 field 4 or 001,4 which seems to contain Basic Setting requirments as a binary number. I can see from my old logs already that this changes when I disconnected the Regulating Flap control Unit. So will take a close look to see if it also changes with PWM. Thanks for the suggestion.

Eureka - I have finally worked out how to do it. I can now see the supercharger magnetic clutch in VAGCOM. :banana:
So I can now log the magnetic clutch, the pressure regulating flap and the supercharger output pressure along with lots of other stuff. None of this is documented by Ross-Tech for the MK5 BLG or MK6 CAV twinchargers. So I have got me a pretty unique label file for these engines now. I will add this to my comprehensive DSG7 label file, and I will be set. I have also found two simple methods of disabling the SCharger. Drives a bit different when there is no boost until 3000rpm. Bit like a GTI I expect :P
Standby for some CSVs showing what is really going on with the supercharger.

Awesome work Logger!!

Can't wait to see the results

:D

Thats amazing that you worked out how to disable the scharger.

So does this mean the control flap is still closed when u disable the scharger till the rpm where it starts to handover to the turbo (around 2500rpm according to the vw site)? Can you also control when the flap opens?

I also look forward to the updated spreadsheet.

An update for those worried about the squeak i now only get it under hard acceleration so it dissipates with time. However i will go with the fix in case it solves my other issue

Nice work, can you post up the vagcom blocks you are measuring as well as the csv file. It will be interesting to try on mine as the sound if still there at the 15000 service they asked about it and they gave an update from VW who are still seeking a solution. Lots of if's but's and maybe's but no definitive answer to when it will be fixed.