TSI squeal noise problem on acceleration

[coastie]

Hey Coastie, What makes you so sure it is happening during engagement of the supercharger magnetic clutch and not disengagement? I would challenge most people to be able to pick when the magnetic clutch engages unless they can see the telemetry. It is just that I reckon it actually occurs on disengagement of the clutch which also occurs during acceleration and typically only a couple of seconds after engagement.
Very often by the time you back off the accelerator the mag clutch has already disengaged long ago. So this is often not the trigger for disengage, although depending on how you drive it can be.
Logger.

Point taken, just my personal experience that it occurs immediately after I press the accelerator down (my impression milliseconds) however does not sound when I lift the accelerator up. That you have produced the telemetry indicating engagement and disengagement of the item makes it even more confusing as there is not a large period of time between the two events. I suspect sometime in the process the friction material between the two surfaces is slipping due to dust or similar by product of the friction material surface causing the noise or as vwweirdo submits a vibration causing the noise.

[logger]

As the water pump builds up with solenoid clutch, the one-piece anchorage plate on the outer pulley starts to vibrate. The volume of the noise depends on the operating conditions. STRAIGHT OF THE VW TECHNICAL BULLETIN

That doesn't actually clarify the engage/disengage thing. The water pump "builds up" all the way to the engines max rpm regardless of mag clutch position, because it is always driven by the ancillary belt and camshaft pulley. The solenoid clutch "builds up" all the way to momentarily after it is commanded to disengage when it does whatever the opposite of building up is. It does point the finger at the (outer) water pump pulley and not the supercharger pulley though, so thats useful info.

Point taken, just my personal experience that it occurs immediately after I press the accelerator down (my impression milliseconds) however does not sound when I lift the accelerator up. That you have produced the telemetry indicating engagement and disengagement of the item makes it even more confusing as there is not a large period of time between the two events. I suspect sometime in the process the friction material between the two surfaces is slipping due to dust or similar by product of the friction material surface causing the noise or as vwweirdo submits a vibration causing the noise.

Yeah I am not sure either. Intuitively I would have thought clutch slipping one or other end of the cycle, but it appears from vwweirdo's reference a high freq vibration of the water pump pulley is what we can hear. From a quick observation I thought I was hearing the chirp just as the solenoid switched OFF, but will recheck. Perhaps it is more inclined to vibrate in an audible manner when it is suddenly NOT clamped to the adjacent supercharger pulley by a strong electromagnetic field.
I will use the VCDS time stamp tool to mark when the chirp occurs and cross reference this to solenoid status and current so I can see for sure what end of the cycle it is at.

You still after the S/Charger data blocks?

[coastie]

Yes please, you can pm them if you wish. I don't have many chances to log but I am keen to put the VCDS to some better use than scans.

[brodzta_GTI]

^^ i second that.. ive read it enough times to know

[logger]

Yes please, you can pm them if you wish. I don't have many chances to log but I am keen to put the VCDS to some better use than scans.

Here you go - I am happy to make them public now:

;# Loggers CAV Supercharger measuring blocks#
;
232,0,Regulating Flap control Unit (J808)
232,1,NFI, (related somehow to G584/J808)
232,2,Regulating Flap position,(actual or commanded), 0-100% = Closed-Open
232,3,Regulating Flap position,(actual or commanded)
232,4,Voltage,Flap Potentiometer (G584), ,Specification: 0.7...4.0 V (5.1 v = sensor disconnected)
;
237,0,Magnetic Clutch Supercharger (N421)
237,2,Magnetic Clutch Current.
237,3,Magnetic Clutch Supercharger,Range: ON/OFF
237,4,Magnetic Clutch Supercharger,Range: ON/OFF
;
241,1,Intake Manifold,Pressure (G583 S/Charger)
241,2,Boost Pressure,(actual)
241,3,Boost Pressure,(specified)
241,4,Boost Pressure,(specified)
;

PM me if you need a complete label file and simple instructions on how to install it.

[Guest]

Here you go - I am happy to make them public now:


PM me if you need a complete label file and simple instructions on how to install it.

just for your own info i know this 236, display field 4, the condition of the solenoid valve (on/off)

[logger]

just for your own info i know this 236, display field 4, the condition of the solenoid valve (on/off)

Yeah thanks, it is already in my label file, however I left it out of the list above simply to remove duplication. . 236,3,4 replicate 237,3,4 but Block 237 is better as it also includes the solenoid current at 237,2 (perhaps by way of PWM) which is missing from block 236.

[gozamet]

Hi all
I'm from Poland and I'm quite new here.
We have also squeal noise problem here
But I have also somthing extra
GOLF 1,4 TSI 118kW
I can hear some clicks from the engine by 1000rpm. No gear, pressed clutch and acceleration. I can hear some switching on and off of some device.
And this is my question: which device makes this cliks compressor or water pump?
Please see movie 1:
http://www.youtube.com/watch?v=5afa_kSzLRI

Next near by 3000rpm I can hear squeal noise (well known problem).
Please see movie 2:
http://www.youtube.com/watch?v=D7DtumvYqG0

And my second question: is the same defect (water pump makes these cliks and squeal noise) or two different (compressor and water pump)?
Thanks for answer and sorry for my english.

[Silvery_one]

I visited a Dealer the other day and they mentioned that some cars (118Tsi) in Sydeny had a retro fit part they were testing over the next few weeks on cars.

If this works then they will retro fit ALL... Hope he was not just keeping me HAPPY...

Stay tuned.

[Guest]

I visited a Dealer the other day and they mentioned that some cars (118Tsi) in Sydeny had a retro fit part they were testing over the next few weeks on cars.

If this works then they will retro fit ALL... Hope he was not just keeping me HAPPY...

Stay tuned.

No def is 100% true i know this first hand