CBZB engine from 2012, with original turbo, odometer says 161k miles. Runs quietly and smoothly engine-wise.

However, since acquired, the car feels a little less responsive than I might guess it ought to, and isn't as good on fuel economy as hoped.

A neighbour with a lot of car experience mentioned at time of purchase that he'd be concerned about the turbo being worn out, on a small capacity TSI with that many miles.

I acquired a secondhand turbo with far lower mileage (<60k I think), but didn't fancy swapping it in without some decent evidence of fault with the original.

I think I found such evidence today, without much effort.

With just 5 torx Tx30 screws removed from the heatshield, I could get it far enough out of the way to get to the linkage connection and carefully remove the C-clip to separate actuator rod and linkage.

If you know what you're looking at, this video may demonstrate the problem reasonably well.

The potential replacement turbo has no such ovalling of the hole in the linkage, and less shaft waggle within the bush that takes it through the housing to the wastegate itself.

Losing all that waggle should help turbo control quite a bit, right?

It can't be good with that much slack in the spindle. But it would still be worth doing some logging of the boost live with VCDS if you have it to see if it's making its correct numbers. Of course it should have underboost codes if not but if it's only a little down it might not be enough to flag them. It can't be great with that mileage if it's the original turbo though.

Good suggestion, thanks @Rheumy

I should be able to gather some such data.

Specified and actual boost, yeah? Anything else good to grab whilst I'm at it?

As long as it's genuine VCDS you hover over the figures and you get pop ups to give you the rough figures to expect. MAF and MAP logged together I think I'd go for but I'm not a tuning or logging expert. Make sure throttle opening is included (I think it will be) possibly shown on VCDS as 'Load' in %. It does need to be done on a nice clear road with a warm engine and full throttle through say third and fourth to show up maximum boost. A good hill is handy to get the boost level up (and stop you getting pulled up by the fuzz!) Don't forget to use the 'Start' button after clicking 'Log' and the 'Stop' button when you have finished. :)

The logs are a great long list of the recorded numbers from your drive which can get a bit confusing so I like to upload the whole unopened log to Tunzilla's free graphing tool. You might have to sign up for a free A/C but it's a handy tool. From there you can see the peaks more easily. The reason I said unopened is because I think if you view the log with something like Notepad first it alters it very slightly and Tunezilla's tool might not recognise it.

Hope to have an opportunity tomorrow.

Many thanks for your time and advice.

Took a pic just now of the elongation in the hole that the wastegate actuator attaches to on another manifold. A really extreme example I expect.

I think the one on the car isn't as bad as this, but it's easy to imagine the electronics/electrics having a hard time trying to position the wastegate accurately with this degree of slop in the system.

Edited 1 October, 20251 Oct by Breezy_Pete