TSI squeal noise problem on acceleration

[cktsi]

Yep DSG, but take off from first, shouldn't do that....

Yes 1st shouldnt do that. But the dsg is just an automated clutch than a traditional auto torque converter so the dsg will need to find friction point first or it will stall the car.

My tip for quick takeoff is either let the clutch engage before smashing down the accelerator or do the following

1. Before take off light accelerator with right foot while putting left on foot brake. Floor your right and lift your left off the brake on take off.

2. Same as 1 but use hand brake instead of foot brake.

For 1 i notice dsg disengages the clutch after a couple of seconds so you apply light throttle while foot braking just 1 second before your planned take off.

I use method 2 cos sometimes i find i get bogged down in method 1.

Sadly 7dsg doesnt come with launch control or you wouldnt have to do this

You will win most traffic light races.

i am posting on mobile but when i get access i will post link of dsg discussion.

[cwcarruthers]

Back to the thread topic... my August/September (can't remember which) build car was initially silent. Then from about 500km it started making (and still does) a soft sneezing/blow off noise when the supercharger disengages. It is very much not a squeak though.
I assume it is when the supercharger disengages because it occurs after I've squeezed the pedal for some performance (love the torque!), but then backed off to light throttle somewhere between 2000-3000 rpm.

Does this timing match with the infamouse squeak, and if it is indeed a different noise, does anyone think perhaps it indicates that the factory has made a change?

[njdavis103]

Hi all,

I am in Devon, UK and have had the GT TSI 1.4 for two weeks. I've done over 2000 miles already and at 1200 miles it started to squeak on acceleration. A short, sharp squeak, audible in the car but worse with the window down.

I went to the dealer yesterday who said it was 'a known fault', so no new news there! However, I then did some digging around the internet to discover this:

In Germany: Cars built from week 45 will have a new waterpump (and Magentkupplung- whatever that is, from the forums of the same site below), so contact your dealers/VW UK now!

http://www.michaelneuhaus.de/golf6/golf6-probleme.htm

Translation

http://translate.googleusercontent.com/translate_c?hl=en&ie=UTF-8&sl=de&tl=en&u=http://www.michaelneuhaus.de/golf6/golf6-probleme.htm&rurl=translate.google.co.uk&usg=ALkJrhil1V4LET-e1DGmBDLV1ltZFRX2dw

So from the end of September 09 cars have been built to this spec, yet VW are not officially advising any changes to cars built prior to this date. They are still waiting to see if this resolves the problem! It is very frustrating but the UK dealer assured me a fix will be on its way and be resolved but could not give a timescale. I hope this new information and it helps.

[cktsi]

Yep DSG, but take off from first, shouldn't do that....

Here is a better thread to pose DSG questions. It delves into how the DSG works... if anything it will help you understand & better what to expect from the DSG.

It's probably worth posting in & reviving this other thread for DSG questions as this particular thread is about the magnetic clutch issue for the supercharger.

[GTom]

Just for those who are having this problem, I'd recommend you contact your dealer again as apparently VW have come up with the solution.

I had the problem (after 20k km) and then the dealer lubricated it a bit and it was fine for 6 months.

The squeal came back however.

Anyways long story short I can't remember exactly but they either replace the pulley or the pulley belt (was occupied doing a few things at once when I rang unf.)

This apparently fixes the problem with the squeal...

[coastie]

Back to the thread topic... my August/September (can't remember which) build car was initially silent. Then from about 500km it started making (and still does) a soft sneezing/blow off noise when the supercharger disengages. It is very much not a squeak though.
I assume it is when the supercharger disengages because it occurs after I've squeezed the pedal for some performance (love the torque!), but then backed off to light throttle somewhere between 2000-3000 rpm.

Does this timing match with the infamouse squeak, and if it is indeed a different noise, does anyone think perhaps it indicates that the factory has made a change?

Completely different the squeak is evident upon accelerating and the initial engaging of the supercharger magnetic clutch. It does not sound when you back off on the accelerator.

[coastie]

Just for those who are having this problem, I'd recommend you contact your dealer again as apparently VW have come up with the solution.

I had the problem (after 20k km) and then the dealer lubricated it a bit and it was fine for 6 months.

The squeal came back however.

Anyways long story short I can't remember exactly but they either replace the pulley or the pulley belt (was occupied doing a few things at once when I rang unf.)

This apparently fixes the problem with the squeal...

This type of fix was attempted in Sydney or Melbourne for someone in an earlier post about six months ago. VW last advised me in late November 09 that there is still no definitive answer yet. Was your fix as a result of a VW Tech bulletin or your dealer just trying something to resolve the problem.

[brodzta_GTI]

its strange.. when there new theres no noise.. then they seem to develop it over time.. we had 3 in the one week at one stage.. personally i love the nosie.. but i can also understand people's frustrations with a "strange" noise comming from the front, they've spent $35,000 on a car..

[logger]

Completely different the squeak is evident upon accelerating and the initial engaging of the supercharger magnetic clutch. It does not sound when you back off on the accelerator.

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.

[Guest]

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.

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

[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.