Polo GTI turbo intermittantly not spooling

[VWindahouse]

Sorry my bad, I though you could never get it to spool so it's probably not the actuator. But that ticking noise is a worry. I say get it someone soon for a professional opinion.

[bn1986]

To me it sounds like (and dont hold me to it) like its either the n75 internals flapping around and vibrating as the ecu tries to regulate the boost, or its the actuator on the turbo, rattling around to the tune of the n75 directions. The N75 is ontop of the heads though, right?

Any tips on how to test the valve and see if its kaput?

[VWindahouse]

Yep the back of the engine and coming off the bend on the TIP.

You can just disconnect the plug and go for a run and see if there is any noise I guess.

[bn1986]

I thought the n75 was under the plastic engine cover? Or is that another 3 way vacuum solenoid of sorts?

[VWindahouse]

Should be directly off your turbo inlet pipe, between the PCV and DV. I think it's the N249 or N112 your referring to, sorry can't remember exactly.

[bn1986]

Thanks alot buddy will experiment with it tonight

[VWindahouse]

Cool best of luck mate

[noone]

A few things to try;
- bypass the N249 / N112 (google for a guide)
- chuck in a spare N75 (I have a spare race version if you need, or if you're close to someone they take 2 min to remove

If it works and stops, makes me think the N75 is on the way out or bad electrical connection. around 5psi is what you'd expect to see if the N75 was disconnected.

Bypassing the other bits just makes sure its not a vac issue (as the vac reservoir can split or one of the 1-way valves could be cactus.

[bn1986]

If I unplug the n75 from the wiring loom but leave it plumbed in will it leave the wastegate open or closed? Should I swap the n75 for a race spec one if it's cactused or just stick to the oem part and get one from vw artarmon tomorrow?

Im in roseville near the 7/11 whereabouts are you?

[noone]

the race one is just to test, feel free to try / buy.
If yours is buggered, you'd likely replace with an OEM (cheaper from ebay if you can wait, no idea what the stealership would charge).

I work in Artarmon, will be around tomorrow, PM me if you want me to have a look.

[bn1986]

Sweet as.. I'll unplug the n75 in about an hour.. I'll let u know what comes of it and I'm. Happy to buy yours if you don't need it?

[bn1986]

IT WAS THE N75

booya!!! PM'ing you noone

[nightphotographer]

I'm having the same problems at the moment, after 20-30 seconds of lots of boost, I go back to NA and do so until I restart the engine. Assuming it's my DV008 so trying to find some synthetic non-lithum based grease - does anyone know of any I could get locally or am I going to have to get it shipped? Car's still driveable, it's just annoying and getting worse.

[h100vw]

I'm having the same problems at the moment, after 20-30 seconds of lots of boost, I go back to NA and do so until I restart the engine. Assuming it's my DV008 so trying to find some synthetic non-lithum based grease - does anyone know of any I could get locally or am I going to have to get it shipped? Car's still driveable, it's just annoying and getting worse.

I doubt the DV is sticking. Just about anything would be adequate to lube the piston IMO.

When you say NA do you mean 6PSI? This would indicate to me the N75 isn't doing anything. If the N75 fails, it fails safe. If it failed closed, the actuator would never open the WG and the turbo would never back off. Same as if you had a split pipe to the actuator, the N75 would have no control and you would have lots of fun for a short time.

Gavin

[nightphotographer]

The reason I thought it was the DV was because when I first starting getting boost problems (after tune and DV upgrade) that's what VCDS was saying was the error. Back then it was only losing power every 1/25 times of starting the car and would be fixed with a restart. Now it's every time after 2-3 minutes of driving/a big squirt. I'll try the N75 - I'm not sure what 6PSI feels like, but it definitely feels NA like there is no turbo at all - it's very economical though