Turbo noise on and off Tdi.

[njg02]

Moved from Polo 6R area.
Hi.
6R Tdi 7sp. No power loss. Good economy. Runs well. Mostly drive with windows down and no aircon. 100km each way to work and back. Travel mostly at 100km/hr nearly always on cruise. Curently at 228,000km.
For about 8 months when going up a slight hill I thought it was cicadas. Now I can hear the noise come on and off as power comes on uphill with windows shut. Not screaming but a squeal sound. It can be heard on the flat as I accelerate from about 1500rpm to about 2500rpm. Not in the low gears though. Not when sitting in neutral or park(no load).
There is oil around the intake to the turbo, from the hose that comes from the rear top of the engine, which I assume is recirc pollution stuff.
Any hints as to what it may be?
Thanks.
Neil

[gldgti]

Given the low engine speed and high load you're describing, it might just be a bit of surge. Hard to say though. If you can get it scanned for faults it would be a good idea, just incase its starting to overboost at low revs (perhaps a sticky actuator) - it might have thrown a fault code at some point (not one that will throw a CEL though).

I wouldn't worry about the oil, pretty normal in the intake parts - but do check the intake hose for cracks etc, you might be hearing a hole. I've heard broken intake hoses long before the hole was big enough to cause a problem.

[njg02]

Thanks mate.
Off to the dealer tomorrow.
It made another different sound when pulling out this arvo.
I'll let you know how it goes.

[Bora Sport]

I was thinking a split turbo hose. Boost is being lost and the turbo is spinning harder to compensate which is a shortcut to the turbo dying early. So I also will be interested to hear the answer.

[Greg Roles]

Dodgey intercooler hose connection? The Golf MKV's suffered from that with their C-clip connections, the MK6's moved to normal screw up clamps. Perhaps the Polo still has some C-clip connections?

[njg02]

Fixed.
They changed something to do with the pollution gear last year after I lost power.
Yesterday they found a bolt had worked it's way loose.
All good this morning on the way to work.