Hi all, i hope their is some here that can shed some light on this problem I'm having. I have had my VRS about 5 years now and about 6 months after getting it I had a full custom rolling road remap done at Jabba sport. 227bhp..Yes please! ever since I get the dreaded 17705 fault code and periodically when driving first thing (when it started from cold) it drops into limp mode, I have over the years just got used to a quick switch off of the ignition and back on again and all is well again. I have had a problem occur in the last year, after I have driven it up to temperature, if I stop for say 20 mins or so, then get in and set off again, i get a really odd noise, it sounds like the turbo trying to spool up but cant properly, on acceleration it judders (like when a coil pack goes, but its not a coil pack) the juddering co-insides with the noise from what I can only assume is the turbo? then after a mile or so the noise goes away, turbo sounds perfect, boosts fine and its like nothing has happened.

I did have my service intervals dropped to every 10K miles due to the remap, but now wondering if this was worth it as im now thinking is turbo on its way out anyway. I has in the last few weeks started to do it more often, this being the reason for my post, im sorry if this has been asked before, but thought i would see if anyone had any ideas....

Sam

secondary air pump (SAI) issue maybe????? not sure

Certainly sound SAI related, on the limp mode/17705 front, check all your breather hoses are intact, as that can affect running when sai system is in play. You could always do what most of us who have not deleted system do, and just wait 60-90 secs for system to cease before driving off and all will be good.

+1 for SAI, but didn't think it came on when hot?

Sent from my Galaxy S2 not a Crapple!

my 4x4 doing this currently

System will periodically self test itself in quiet moment in the ecu duty cycle regardless of temperature - quite normal.

cant you unplug these and put in a resister? i believe the eml comes on once every 4 starts

I had hoped its isn't the turbo, not sure the SAI is much better, they are a small fortune arbt they?? One other thing I get, every now and then, I can be cruising at 70mph and monetarily all the power goes away, then after a second or two it all comes back? Is this related to the vacuume pump too?

search for sai delete threads its a common mod

Sounds like you have a air leak in system somewhere, as said above i would check breather system before you start ripping bits off it just in case its that,

have you tried cleaning throttle body out

Not had anything out or cleaned anything yet, some was saying the N75 might need up rating due to the remap?? Could this be part of the 17705 problem? Looking at. J. As a replacemet? Is this worth a shot, can the SAI be serviced, or is it a take it out, throw it away and fit a new one? Not sure I want to "delete" it as I'm sure it must surve a purpose for somting??

Check the middle of the Y pipe that connects to the cambox, and also the hard pipe that goes to the t piece on top of the oil filter housing for holes. Also, check the wiring connector onto the N75 valve is not loose or showing signs of corrosion, I use a non conductive silicone grease from maplin that I coat terminals in as I disturb them.

17705 is a pressure drop between turbo and throttle valve - on my car I found a dirty throttle body aggravates this code, but could also be the diverter valve starting to perish if it is the oem one. I would check the pipes I mentioned earlier before getting in too deep with replacement N75 valves. cntuning on here is your man to advise on N75 valves, but from memory, I seem to recall he said the original is quite up to the job I think.

SAI pump can be rebuilt with bolts rather than rivets if the housing is starting to leak, otherwise it is a new/secondhand replacement, or a delete. It's purpose is to inject oxygen to the cat during cold start to enable a faster cat warm up - emission controls

I'd say your DV is goosed. 17705 & momentary loss of power at cruising speeds is classic DV seal failure. Have a look on uk-mkivs.net there's a massive thread on the dreaded 17705 code.

As already stated SAI repair is easy. Drill out the failed rivets & replace with nut's & bolts took me about 40 mins to do a few years back. Make sure the corrugated pipes are on properly too

So would the SAI only give the problem on acceleration?? I thought it would create a constant drone until the pump stops?? It's fine on idle or gental acceleration l, only when you pull out a junction with a bit of haste dose the odd noise occur... Will get in the engine bay next week end a check all the hoses.

I've just deleted my SAI and to be fair, my cars still doing this also. It's a strange Feeling whilst accelerating, it will go first of all, come under load, the car than flat spots, recognises the call for more boost/power then accelerates again. To me it feels as if the boost regulator is delayed or the actuator/watergate is periodically sticking. It's very weird tbh.

I've Also removed the N112 and N249 valves - dunno if that's worth mentioning

I have tried to record it so you could hear what it sounds like, but it's just a load of wind noise. To me, dare I say it, it sounds like the turbo being starved of oil initially, then lubs up and away we go, does this happen?? And if so, I take it that's bad??

I had a new throttle body fitted when the 17705 fault started under warrenty, and turbo pipe to, they did a whole load of replacemet bits on their technical bulitins, lucky I'm good mates with head machanic so he sorted it all for me even with the remap, although we did have to stop as the next stage which was a fully driven data log which was going to be sent of to Skoda, boosting at 140% I think may have raised some eye brows at head office!!