hey guys so i got the worse code ever 17705. i have a 1.8t engine. i hav done numerous hours of reading posts and cant seem to figure out the problem! i had a smoke test done on it and the shop didnt find any leaks they said. i hav also recently replaced my pcv system up on the intake inlet bracket and under it. so when i drive the car bogs down when i accelerate and makes a ticking noise which is coming from the driver side (seems like right by the firewall). ive had my exhause checked for leaks and it came out good too. ive tried putting a new N249 valve in (EGR solenoid) and ive tried a new DV which both didnt make a difference. the shop i took it to said the ticking was coming from the N75 valve. im just not sure i want to spend the money on a part that isnt evn throwin a code.....any help guys?

thnx

If you've got a friend with a 1.8T car (Audi, Jetta, Golf, whatever) with a working N75 valve then just swap them over and see if that helps. Its just a case of removing a multiplug and some hose clips. If the N75 is the problem they are about £60 (about $90) to get a new one.

ive been lookin for one to swap. i feel like the ticking is really the sound of air getting out of a hose. i checked the pressure hose last nite since tht seems to b where alot of people find their problems but it look ok, a little gunk up on the C spring. itd make sense if the N75 is making the sound since it seems to b comin from like under the steering wheel near the firewall but i feel since the car goes into limp it could b a big hose.

Ticking could still be the valve. If the valve inside the N75 has failed then air flowing through it (when it shouldn't be) would cause the valve to rattle. If you have VAG-Com you should be able to measure the % the N75 is opening under boost, my Liquid Gauge does it with a feed from the OBDII port so I would've thought VAG-Com would do it as well. From reading your first post again it sounds like the N75 could be stuck 100% open, meaning the wastegate is stuck open all the time as well, that would be why the car feels bogged down.

Edited 24 August, 201015 yr by chicken_eyebrow

hmmm......alright. like i said its a VW if i havnt stated tht yet but i brought it in to my preferred shop not a dealership but an older guy there said it should b tht vlave. but the problem is the name he was callin it was actually the n249 valve. so thts why im sketched out on replacing. an since its electrical its $100 USD i cant return haha. but like u said i need to find a friend in my area! ive literally been diggin thru my engine the last 2 months searching for bad hoses. i feel like all the hoses can sorta b bad! :no: just trying to explain my situation to see if anyone has ever experienced it. frm the ound i hear it it was a hose especially a big one i thnk i would hav found it.

Everyone's had the 17705 code at some point on their 1.8T engine :(

I tried new DV, checked all hoses, unplugged MAF, etc., etc. Guess what? A new N75 valve fixed it and I haven't seen it since (touch wood). It's got to be worth a try

really!!!!!???? im gettin excited, but i hav multiple times b4 thnkin i fixed it! i unplugged my n249 vlave one day and plugged it back in. the light went off, thought it was the best day ever so i got a new one and it came back!! haha. do u thnk buyin a used one would b a safe bet? or should i go brand new? itd b so nice to hav a buddy around. but im in the States and i dnt thn il find one on here!!!! but this is a sweet Forum. anyone else replace the n75 and hav luck?

is the ticking possible coming from the charcoal filter and nothing to do with the code? 17705 is a big can of worms but have you done things like "throttle body clean" / "throttle body reset" the hose from the top of the turbo to the DV can be a culprit (you should see oily residue around the connector if it is leaking - mine was the other day) maybe try the DIY boost leak tester to check for leaks yourself.

if you are looking for someone nearby try the vw vortex forum really good site and some freindly people on there too (some evil ones as well but there you go )

really!!!!!???? im gettin excited, but i hav multiple times b4 thnkin i fixed it! i unplugged my n249 vlave one day and plugged it back in. the light went off, thought it was the best day ever so i got a new one and it came back!! haha. do u thnk buyin a used one would b a safe bet? or should i go brand new? itd b so nice to hav a buddy around. but im in the States and i dnt thn il find one on here!!!! but this is a sweet Forum. anyone else replace the n75 and hav luck?

I wouldn't buy a second hand one, think about it logically, yes it might be cheap but why would someone be selling a second hand valve? probably because they've replaced their broken one with a new one and have one to flog cheap lol.

As said, are you sure it isn't just the charcoal canister ticking, which is pretty normal and the bogging could be needing a throttle body reset?

hmmm......alright. like i said its a VW if i havnt stated tht

same engine in most respects

the problem is the name he was callin it was actually the n249 valve.

Totally different valve. The N249 valve is at the front of the engine underneath the bracket in front of the inlet manifold, the N75 is mounted in the air pipework between the air filter box and the turbo. If the N249 valve was broken you would get a fault code and the DV would make a chattering noise when you lift off.

i cleaned my throttle body. it wasnt dirty at all. i little carbon on the walls but barely any. im not sure about this canister tho. ive nvr heard of it. ticking did begin b4 check engine light came on. about a month before. but ive read tht the code 17705 doesnt always thro a check engine light. but it has now on my car. but whn the ticking began i def. felt the power loss.

ya im aware of whr those 2 valve are and ya i dnt believe it was my n249 and im skeptical about the n75. i dnt here any noise coming from the n75 whn the car is idling.

Are you sure the ticking isn't just coincidence? I'd seriously try the N75 valve. Every two weeks I'd clear the code and reset the EML, just for it to keep coming back, and the car would start running like a bag of marshmallow farts, without any boost. There wasn't any noise from the N75 either.

Maybe I just got lucky but it sounds like you've tried everything else so you just have to move on to the next potential fix. Have a search on here for the 17705 code and you'll see what I mean

i hav searched! lol seems like everyone has fixed it in a diff way haha. i figured the n75 would thro its own code tho....but yes i no i need to keep trying. and the ticking could b a coincidence but i doubt it. since its started the car has ran like ****. seems like i hav boost at lower speeds. right off the start i cant get it up to around 5500 RPM but at high speeds like freeway driving if i pin itit doesnt get into the high RPM's unless u hold the throttle down for some time and get it up ovr 100 MPH. which i hate doin whn its running like this.

also whn accelerating there is a smell that comes intot he cabin. i wanna say it smells like exhaust but as i mentioned earlier the exhaust isnt leaking. idk if knowing tht there is a smell helps define a certain problem. let me know wht u thnk guys

thnx alot!

Have you got anywhere near you where you can put it on a rolling road? That way someone could have a listen to the N75 and check the smell out while you load up the engine.

by tht do u mean like a small hill whr i cna put it in neutral and rev it get the load going? also i bit more info i left out. so outta the month tht the light has been on there has been a couple randomly occuring days whr the light is off. i figured if it was a actual boost leak the light would nvr go off unless fixed.

Usually the light won't go off until you clear the fault code, especially if there's a big leak, so I'm not sure why it would just randomly go off :S

By rolling road I mean like a dyno, where you measure the BHP of your car (your nearest tuning shop might have one), at least it will let someone examine your engine while the car is actually running whereas if you're driving it down the road and listening to it then it's just guesswork as to whats happening in the engine bay.

i dnt no of the nearest dyno but im sure tht would help since im always observing it with no load. i feel like since the light went off randomly it could b a sensor but idk. after driving and i put the car in park it will rev between 600-1100RPM only after driving and in park tho. thats where i feel there is a boost leak. i no peole are pointing to the N75 but i just dnt feel that is the answer.

thnx guys

If you are getting a smell in the cabin when driving hard then it is coming from the engine bay and the usual culprit for that is the Crank case breather system, you said in the OP that you have replaced some of the PCV under the manifold but as well as the one that goes from the inlet mani down to the PCV Valve there is a Y shaped pipe at the top right of the engine as you look at it from the front, it splits due to the gases from the crank case being corrosive to the rubber. when you changed the pipe under the manifold did you clean/replace the PCV Valve? as a stuck one way valve can cause a boost leak into the same Y pipe which will cause more smell and poor performance.

A boost leak tester fitted to the TIP (with the breather blocked off) should eliminate most pipes but if the leak is on the VAC side then it can take a bit more effort. I replaced the one under the manifold (also put extra check valve inline - got extra 2psi) I replaced the Y pipe and the one under it. I also replaced DV, both Turbo to pancake pipe silicone bits, large pipe to the DV, and some of the vac lines before I was clear of the code.

Edit

Just reread your last post and if it is hunting at idle then you are definately looking at a VAC leak. you need to check all the pipes visually you can also try spraying some carb cleaner or fast start around the vac lines, if the revs increase then you have found the source of the leak, but if you had to replace the one under the manifold then the Y pipe and the other one will need replacing as well. HTH

Edited 25 August, 201015 yr by karlbar2k

thnx for the advice on my engine i dont have that Y piece of hosing i do no wht u are talking about tho. i chkd the idling again and it seems to idled between 600-1000RPM just sitting in park.

Edited 25 August, 201015 yr by pete6810

the pipe work depends on the engine code some have more hardlines and some like the ARX in mine have loads of VAC lines. You will need to have a look on the engine and let us know what code it is (will be three letters like ARX AUQ AUM etc) I think it is next to the Cambelt cover toward the front but not 100% someone will correct me shortly

i have a VW, its a AWD. and for wht ive read they are the worse of the two engine styles, the other being a AWW. so ive done more reading and hav read that there is a hose that connects the intercooler pipe and the turbo. i took a look at it and didnt see any tears or rips in it. also that isnt in the position where im hearing the ticking noise, again since the code went off for a whole day like twice now im torn between a electrical problem and a hose problem.

Maybe worth checking the wiring from the engine loom/ECU to the multiplug on the N75 valve.

If the wiring is damaged and the ECU can't communicate with the N75 then the N75 will fail in the open position, as a safety feature, so the wastegate stays fully open. This is to prevent the turbo overspeeding. Because the wastegate is open, the turbo isn't able to provide the pressure in the inlet that the ECU is expecting so the ECU throws a "17705 pressure drop between turbocharger and throttle body" code.

If the wiring is just slightly nicked or crushed then that could be why its an intermittent problem as you say.