Whining on accel, deccel over-run delayed + timing chain tensioner?

[R1600Turbo]

So I've been noticing a couple things lately on my '09 GTi. (TSI) With the windows down, I can hear a whining noise when I accel. It follows the rpm of the engine, so it will also happen parked and revving the engine. Also, when cruising in gear, if I let off the accelerator it takes a few seconds for the overrun to kick in. Like, the RPM's will hang for a few seconds, then you can feel the engine braking begin. No CEL, not sure if any hidden fault codes. Can the CEL check at Autozone tell me anything, or do I need to spend $100 for the VW dealer to do it?

I thought I read somewhere that a faulty diverter valve could be the cause, but wanted to get a few opinions first.

Last, when's the recommended mileage that the timing chain tensioner be replaced? Car has 54k miles.

Thanks!

 

[R1600Turbo]

Updated to a Rev D diverter, whining still there.

Still need an answer on the tensioner(s).

 

[zrickety]

You would have a CEL if it were the tensioner. Sounds more like a turbo issue. Maybe a small leak somewhere. Your car is low miles...

 

[R1600Turbo]

I will say the Rev D did help a bit with throttle response, but didn't notice much else. I did notice when I was swapping it out that there's quite a bit of oil leakage on it and the connector, and the old valve was slightly covered in oil when I pulled it out. Not sure where it's coming from. Wondering if I have a PCV issue.

I can look around for anything that's loose, but it'll have to wait until next weekend since I live in an apartment and it's dark now when I get off from work.

 

[zrickety]

The rev hang you refer to is normal...does it last more than a few seconds? The oil is from your PCV but likely also normal. What kind of oil changes are you doing?

 

[R1600Turbo]

I think the Rev D may have helped with the rev hang a bit, have to drive it more to confirm.

Oil changes every 5k, Mobil 1. Have to double check the weight when I get home, maybe 0w40? The car isn't really burning any, very minimal loss between changes. Haven't needed to top it off.