mbames

In my continual playing to get my turbo to work properly I had a fiddle on Tuesday. Initially I disconnected the vacuum hose from the n75 to the turbo. I was able to suck that and get some movement, but not much - I could just seem something on the vacuum mechanism working.

From under the car I was unable to really push the control arm at all.

Next I applied a vacuum to the hose and that seemed to get some more movement from the control rod. So I assume that means the vanes can’t be totally gummed up.

I reconnected the hose to the n75 and started the car. I was interested to note that as soon as I started the car a vacuum was applied to the turbo unit, and that did not seem to change even if the engine was revved. I thought the purpose of the n75 was to adjust this as the rpm changed? and why should a vacuum be applied as soon as the car starts and idles?

Could this be an indication that the n75 is knackered again? Nothing shown in vag-com since I cleared the last overboost error a few weeks ago (caused when the car went into limp home mode).

Cheers,
Matt

Lummox

The VNT arm shouldnt move when the engine is revved, if should remain open as the turbo doesnt require boost if you stood still. The only way to check it effectively is in measured value clocks up the road.

Also just because the control arm is moving doesnt mean the vanes are.

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mbames

mmm, so maybe I need to actually take the turbo off and apart to check that it is working as it should?

greg123

Why don't you run a output cycle in vag-com. I thought a cars were seized and I ran it, the arm could be seen working perfectly and changed the engine note which it wouldn't have done if the vanes were stuck. It opened the vanes for about 10 sec then shut them then open them - info on how to do it on here or tdiclub I'm sure. or pm me.