TSI squeal noise problem on acceleration

[MurphyTheElf]

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

Yes, a 1.4 litre GTI.

[logger]

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)?

No - Would seem it that it is a pre requisite for the mag clutch to be engaged for the flap to close. So when it is disabled, no clutch and therefore no flap action.

Can you also control when the flap opens?

Not exactly - But I can disable it too.

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

I sometimes get the chirp too. I was only able to identify it after downloading a sound recording of it from erwin. To me it is a non event, however I appreciate how it could bug others.

Nice work, can you post up the vagcom blocks you are measuring as well as the csv file.

Sorry - Nope not yet. Bit much time and effort has gone into finding them. Want to chat with the Ross-Tech guys first but will prolly make the whole label file avail soonish.

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.

Yeah I would not be holding your breath on a fix anytime soon.


Anyway here is the XLS log. Again, like some of the other stuff I have posted, it highlights how briefly the SCharger actually runs for. Typically the Magnetic Clutch is engaged for 2 or 3 seconds at a time. Three minute drive at varied speeds, I think it runs about Ten times. Also records the torque commands from the gearbox as it often intervenes. Unfortunately the sample rate is ~ 1/sec. A trade off between sample rate and logged blocks.

Enjoy...

Charger Log

[coastie]

Thanks for the spreadsheet. Interesting data and I like the comment notes it helps explain a lot more. I hope the Ross Tech staff reward your effort and IP.

[nicandlance]

Wow, they really are trying to walk allover you, I really despise this ( walking all over the little man) because i'm quite spitefull when it comes to things like this, i would do the lemon thing, especially on a Saturday, there busiest day. When they see potential customers looking at your car reading the list of problems then driving away......... bottom line pain for the dealer principal.

I'm actually getting angry reading this. Ha!

I had really bad experiences with VW as well. My 2006 beetle had this annoying groan between gear changes and when I went accelerate. At first they treated me as though I was imagining it, until the noise progressively got louder and they couldn't ignore it. Went back to the dealer around 12 - 14 times within 6 months, came back 'fixed' about 4. Noise reoccured again. I wrote to VW demanding a new car too. No joy. I was angry, frustrated and bitterly disappointed that my beautiful new car could give me so much grief. Ended up the noise was a solenoid valve (or actually - something attached to it) 10 months down the track, finally fixed.
It is incredibly annoying to sit down and painstakingly research a car to make sure you've made the right choice, only to have ****ty niggly and frustrating things happen....

[logger]

Did another run this morning. 32 minutes drive around suburban Melbourne. Supercharger ran for total of 109 seconds or 6% of the time. From a cursory look the average engage time was still just on 2 seconds with the max period of around 3 seconds. XLS is ~ 8,000 lines and 0.5mb. If someone is good with Excel & feels so inclined....it would be good to to work out what the actual min, max and average clutch engaged periods were. along with the number of cycles.

138.6	 
138.72	 
138.83	 
138.94	 
139.05	engaged 
139.19	engaged 
139.3	engaged 
139.41	engaged 
139.53	engaged 
139.64	engaged 
139.77	engaged 
139.9	engaged 
140.01	engaged 
140.12	engaged 
140.23	engaged 
140.36	engaged 
140.47	engaged 
140.58	engaged 
140.7	engaged 
140.81	engaged 
140.96	engaged 
141.07	 
141.19	 
141.31	 
141.42	 
141.54	 
141.65	 
141.76	 
141.88	 
142	 
142.14	 
142.26	 
142.37	 
142.48	 
142.59	 
142.71	 
142.82	 
142.93	 
143.04	 
143.15	 
143.28	engaged 
143.4	engaged 
143.51	engaged 
143.62	engaged 
143.73	engaged 
143.85	engaged 
143.96	engaged 
144.07	engaged 
144.18	engaged 
144.29	engaged 
144.41	engaged 
144.52	engaged 
144.63	engaged 
144.74	engaged 
144.85	engaged 
144.98	engaged 
145.1	engaged 
145.21	engaged 
145.32	engaged 
145.43	engaged 
145.55	engaged 
145.66	engaged 
145.77	engaged 
145.89	engaged 
146	engaged 
146.14	 
146.25	 
146.36	 
146.47	 
146.58	 
146.71	 
146.82	 
146.95	 
147.07	 
147.19	 
147.32	 
147.44	 
147.55	 
147.66	 
147.77	 
147.9	 
148.02	 
148.13	 
148.24	 
148.36	 
148.49	 
148.61	 
148.73	 
148.84	 
148.97	 
149.1	 
149.22	 
149.33	 
149.44	 
149.55	 
149.69	 
149.8	 
149.92	 
150.03	 
150.14	 
150.27	 
150.39	engaged 
150.5	engaged 
150.61	engaged 
150.72	engaged 
150.86	engaged 
150.97	engaged 
151.09	engaged 
151.2	engaged 
151.31	engaged 
151.44	engaged 
151.56	engaged 
151.67	engaged 
151.78	engaged 
151.89	engaged 
152.03	engaged 
152.14	engaged 
152.26	engaged 
152.37	engaged 
152.48	engaged 
152.61	engaged 
152.73	engaged 
152.84	engaged 
152.95	engaged 
153.06	engaged 
153.2	engaged 
153.32	engaged 
153.43	engaged 
153.54	 
153.65	 
153.78	 
153.9	 
154.01	 
154.12	 
154.23	 
154.35	 
154.46	 
154.57	 
154.68	engaged 
154.79	engaged 
154.91	engaged 
155.02	engaged 
155.13	engaged 
155.24	engaged 
155.35	engaged 
155.48	engaged 
155.6	engaged 
155.71	engaged 
155.82	engaged 
155.93	engaged 
156.05	engaged 
156.16	engaged 
156.27	engaged 
156.38	engaged 
156.49	engaged 
156.61	engaged 
156.72	engaged 
156.83	engaged 
156.94	engaged 
157.05	engaged 
157.18	engaged 
157.31	engaged 
157.42	 
157.53	 
157.64	 
157.77	 
157.88

[logger]

This one shows the Current regulation to the supercharger mag clutch at 0.1 sec intervals. Interesting how if can spike the Amps to 1.5 on engagement and then back off a fraction of a second later. Perhaps this is the PWM doing its thing to minimise engament jolt. Also it appears to regulate the Amps within a run cycle too. Significant point is that there is more to it that just ON or OFF.

Time	 Amps
167.55	0
167.67	0
167.78	0
167.89	0
168	0
168.12	0.44
168.23	0.52
168.34	0.48
168.45	0.56
168.56	0.56
168.69	2.72
168.82	2.72
168.93	2.72
169.04	2.72
169.15	2.72
169.28	2.72
169.39	2.72
169.5	2.72
169.63	2.72
169.74	2.72
169.88	2.72
170	2.72
170.12	2.72
170.23	2.72
170.34	2.72
170.46	2.72
170.57	2.72
170.68	2.72
170.79	2.72
170.9	2.72
171.03	2.72
171.15	2.72
171.26	2.7
171.37	0.74
171.48	0.54
171.6	0.26
171.71	0
171.82	0
171.93	0
172.04	0
172.16	1.52
172.27	0.7
172.38	0.48
172.49	0.52
172.6	0.56
172.73	2.52
172.85	2.7
172.96	2.7
173.07	2.7
173.18	2.7
173.3	2.7
173.41	2.7
173.53	2.7
173.65	2.7
173.78	2.7
173.91	2.7
174.02	2.7
174.13	2.7
174.24	0.6
174.35	0.5
174.47	1.52
174.58	2.7
174.69	2.7
174.8	2.7
174.91	2.7
175.04	2.7
175.16	2.7
175.28	2.7
175.39	2.7
175.5	2.7
175.63	2.7
175.74	2.7
175.87	2.7
175.99	2.7
176.13	2.7
176.24	2.7
176.36	2.72
176.47	2.7
176.58	2.7
176.71	2.7
176.83	2.7
176.94	2.7
177.05	2.7
177.16	2.7
177.3	2.7
177.41	2.7
177.53	1.24
177.64	0.56
177.75	0.5
177.88	0.08
178	0
178.11	0
178.22	0
178.33	0
178.47	0
178.58	0
178.7	0.44
178.82	0.62
178.93	0.5
179.06	0.58
179.17	1.16
179.28	2.7
179.39	2.7
179.51	2.7
179.64	2.7
179.75	2.7
179.87	2.7
180	2.7
180.12	2.7
180.25	2.7
180.37	2.7
180.48	2.7
180.59	2.7
180.7	1.24
180.82	0.56
180.93	0.5
181.04	0.08
181.15	0
181.26	0
181.38	0
181.49	0
181.6	0
181.71	0.7
181.83	0.48
181.96	0.5
182.07	0.5
182.18	0.54
182.29	2.66
182.4	2.7
182.52	2.7
182.63	2.7
182.74	2.7
182.85	2.7
182.96	2.7
183.09	2.7
183.21	2.7
183.32	2.7
183.43	2.7
183.54	2.7
183.67	2.7
183.79	2.7
183.92	2.68
184.04	2.7
184.18	2.7
184.3	2.68
184.41	2.7
184.52	2.7
184.63	2.68
184.75	2.7
184.86	2.7
184.97	2.7
185.08	1.08
185.19	0.58
185.32	0.54
185.44	0.06
185.55	0
185.66	0
185.77	0
185.9	0
186.02	0
186.13	0

[LiFers]

XLS is ~ 8,000 lines and 0.5mb. If someone is good with Excel & feels so inclined....it would be good to to work out what the actual min, max and average clutch engaged periods were. along with the number of cycles.

Pivot tables are your friend. They will take MBs of data in clean tables and show you calculated values within seconds. They can be graphed with 1 click.

If you want instructional help with excel pivot tables, please msg me.

Dom.

[golfyvic]

I'll put my hand up for another GT owner who has the noise.

Like Paul haven't really let it bother me as it happens rarely and before the supercharger (or while it is about to kick in)

Yeah me too... Hasn't happend for a while, all though now I notice sometimes when I put smash the pedal down (not when the engine's cold!) I get a total loss of power for a second. Extremely annoying!!!!

[cktsi]

Yeah me too... Hasn't happend for a while, all though now I notice sometimes when I put smash the pedal down (not when the engine's cold!) I get a total loss of power for a second. Extremely annoying!!!!

Do you have a DSG? If it's a DSG that "loss" of power may be due to it swapping cogs if it "guessed wrong" when trying to anticipate the gear change.

If it's a manual.... whole different kettle of fish.

[golfyvic]

Do you have a DSG? If it's a DSG that "loss" of power may be due to it swapping cogs if it "guessed wrong" when trying to anticipate the gear change.

If it's a manual.... whole different kettle of fish.

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