Turbocharger Wastegate Solenoid

So, my 2003 TDI Golf has become remarkably nutless in the past couple of weeks. I noticed that the turbo never kicks in at all regardless of how i drive. I've got a new error code on the check engine light that says P0246 (Turbocharger Wastegate Solenoid 1 High Voltage). I would very much like to make my turbo work again, as the Golf _DI is not nearly as much fun to drive. Before buying a scangauge and running the numbers, i read over the whole turbo removal, VNT overhaul, rebuild procedure, and it sounds like a lot of work. I don't know where to find the solenoid, and i'm hoping it may be something that's easier to fix. Anyone have any good tips on where i should start?

Thanks!

VW seems to have used a poor choice of words to describe the valve. Your turbo doesn't even have a wastegate!

I'm going to assume they mean the N75 valve. It's a solenoid with a couple vacuum hoses attached to it that sits on your firewall. One of the hoses will goto the VNT actuator on the turbo. (There's a couple solenoid valves that look identical on your firewall, find the one that is connected to the turbo, that's the one you need).

They're at the very top of the firewall, easily visible.

Plugged that DTC code into Ross-Tech wiki and got nothing. You should try finding someone with VAG-com to take a look at it. Not only does it give you the correct codes, but you can also diagnose the turbo directly.

Yeah, a Vag Com would be nice. I also have two other codes showing (P0671 and P0673), but they're both Glow Plug codes as far as i can tell and probably not related to the problem.

I looked for the N75 valve this morning and did notice the several identical looking solenoids. They looked like they couldn't be that expensive. Maybe i'll just swap it out and see what happens. If that is the problem, would the ECU just detect that the problem is solved and start firing up the Turbo again, or would i have to do something to re-set it?

It is likely that your glowplug problem is the harness, not the glowplugs. Any cheapo multimeter will tell you... just check the resistance of each glowplug. If they are all the same, use a really good contact cleaner on the glowplug harness connections... I recommend Caig's DeOxit and ProGold (you'll find them at most Radio Shack stores or online -- not cheap, but work great!).

On your firewall, there are two vacuum solenoids. One is all black, the other is black and white. The all black one is your EGR valve controller, the black and white one is the N75 valve. It'll be the one on your right as you look at them. Now would be a good time to replace the vacuum hoses, too... as long as you are in there. They only last about 5 years, and you'll have the same sort of problem (low power) if they crack and or leak.

I pulled the N75 valve out and got a look at it. My Haynes manual says that the resistance across the terminals should be 25 to 45 ohms, and i'm measuring 4.8, which could be the problem. I've also read in some of the various descriptions on here that i should be able to test it by blowing through the valve. I get a lot of resistance to moving any air through the two larger ports and can't move any at all through the small one on top. Hmmm.

Sounds like it's dead. $69.95 over at TDIparts.com:

http://www.tdiparts.com/catalog/product_info.php?cPath=29_74&products_id=447

Yeah, i'm hoping that's the problem. I got impatient and tried the local dealers, but they're out of stock. I guess i'll have to wait a few days. Thanks for your help, everyone!

Don't buy it at the dealership... you'll pay too much. Buy it from TDIparts or another discount supplier. TDIparts ships quick. WorldImpex is closer to you, so you might get it even sooner if they have it in stock.

Get the N-75, seems like yours has hung itself up a long time ago...

Peter(TDIparts)
Worldimpex(Joe/John, etc...)
AZautohaus

They are all good vendors, just who can get it there first!

About the GP harness, clean all contacts w/radio Shack electric cleaner @ Q-tips. Insert the Q-tip into the press cap for the glow plug AND rotate a couple of times, do this two/three times(new tips), to all press caps.

Try this before buying a new harness.
The electric cleaner will clean your MAF sensors contact really nice, so it is advisable to purchase...

Success

Thanks for the tips everyone. My new N75 came in today, and the turbo spooled up like a champ. The kick felt even better than usual after getting used to an NA diesel for the past few weeks! My impatience actually ended up working out with the dealer. They would have charged $78 if in stock, but they were out. I thanked them anyway and said i'd order it online since it's cheaper, and they offered to bring one in in a day and sell it to me for whatever price i would have gotten online. Worked out for me!

It's nice to get through my first repair beyond basic maintenance with a good feeling and not too much out of pocket. Thanks for your help!