What's this?

[Rushn]

Plastic bottle of some sort with a green screw-on lid, tucked way down low in the engine bay under where the battery would be (GTI), passenger side. Difficult to get at.

I don't have pics, but can get some if needed.

Cheers

[staz88]

Power steering fluid.

[nomadx38]

Sorry staz88 it is not power steering fluid. The power steering for the polo is a closed electric system pumping hydraulic fluid.

No the green bottle under the left headlight is the oil container for the 7 speed Mechatronics Unit. Apparently it's designed to last a life time so don't bother changing it.

[alexaescht]

What's this?

I'd love to agree with you nomad, but I pulled off the fog light cover (on the battery side) of my Polo and it has the same green bottle with a green lid. If you check my signature, I've got a manual - so I don't think it's DSG fluid. I'd get a photo for you but it's in at Berwick Prestige getting its 45,000 service.

[Diesel_vert]

I think staz88 is correct, it's the reservoir cap for power steering motor/pump unit.

[nomadx38]

I'm always willing to be corrected and I think it could actually be for the power steering.

Upon checking the rack and pinion I can see some pipes heading down and around to the front which could be for the power steering. Personally I thought it was for the gearbox because its right next to it and the Polo does have electric / hydraulic steering, but hey you learn somthing new everyday

Thanks for the insight!

[gavs]

What's this?

I can confirm that it is the power steering fluid cap. The mechatronics unit while having its own oil supply contains all its oil inside itself.