"Squeak" from turbo? At specific rpm

[DCS]

Hi all,

I've got a very annoying issue where I think the turbo is squeaking at the point it engages (~1500rpm).

I have a 25 plate leon st with the 7 speed dsg. 1.5etsi.

If I take my foot off the accelerator it will momentarily squeak as it passes 1500rpm on its way to zero.

If I put my foot back down it will squeak momentarily as the turbo engages again around 1500rpm.

I also think it is turbo related as if I put the car into neutral and rev past 1500 it does NOT make the same noise and my understanding is that the turbo does not engage in neutral.

I had it investigated at my 1st service by seat but they were predictably rubbish, saying they could hear it at first, serviced the car and claimed it was not possible to hear after the service. It happened again immediately on the drive home.

The after sales guy even said "perhaps it's meant to sound like that"... I have tried to record it but cannot get the sound to record, it's not loud, but it is noticable.

I was wondering if it might be the bearings on the turbo? I can live with it but if it's reducing the lifespan of engine parts then I'd rather get it resolved.

Does anyone else have this issue or can corroborate my thinking it is the turbo bearings?

 

[mty12345]

Definitely isn't going to be the bearing IMO, more like an actuator or something else entirely. Turbos run at such high speed and close tolerances, that any problem with the bearing would be evident at all rpms, and it would probably fail pretty much immediately.

 

[James_R]

It's the starter generator operating during regenerative engine braking and when it starts the engine again after.

A completely normal, harmless characteristic.

 

[DCS]

It happens when the engine remains on as well, not just when it goes from 3k to 0 and "coasts".

It can be running and will squeak when the car changes gear and lowers the revs to minimum.

Is hard to explain but it only makes the noise for half a second as it passes that specific rev range.

It's the starter generator operating during regenerative engine braking and when it starts the engine again after.

A completely normal, harmless characteristic.

Are you saying its normal, or just highlighting what you think it is, making the noise?

 

[James_R]

Without actually experiencing the noise it's difficult to be 100% accurate, but based on your initial description it sounds exactly like the starter generation operating.

 

[DCS]

I'll try to get it up on stands and (carefully) run it to record the noise

Thank you

 

[BoomerBoom]

I hear a squeak in my DSG, but only when the engine is starting or the regen kicking in, as James says.

It's not really intrusive, so yours might have a belt/tensioner issue if it's very loud?

The lurch as the car switches from regen to brake is far more annoying, or the DSG going nuts down hills and hitting 5k revs in 3rd.