Mar 17, 2007
Yes keep me posted, Im always interested!!!
I am going to change my N75 valve. Where is it located? anyone have any pics???
Ill take some pics tomorrow for you but its pretty simple, Small hands would be easier.
Take out your drivers headlight as its easier to get to.
Its located about half way down the left hand side of the engine bay at the front. Above your diverter valve..Are you changing that too????
Theres a couple of things i am having done tomorrow.
I need a new change control valve as one of nozzles have broken so theres a vacum hose which is not connected to anything. At the same time i need to replace another vacum hose which runs from top of the cylinder head to somewhere near the manifold.
Having the N75 replaced to just a standard one, decided against the J as need to put the car back to standard code every now and then.
Also having the rocker cover gasket replaced as its leaking.
And finally upgraded the spring in the forge diverter valve i already have to one with higer PSI rating which wil hold the boost better..
I am hoping after all this the car will run a lot better with better thottle response and i am hoping ill get back the boost its been leaking for a long time....
Is this the location of the diverter valve (this might be a LHD) i am not sure.
That picture shows both the valves, although the N75 is connected the 710 is missing.
The op say's you can change the diverter valve from the top, but i have tried and it is the biggest PITA in the world
I changed mine by removing the pan under the car and there is it right at the front of the engine on the drivers side, it is a little tricky to replace the 710n as the pipe is held on with those metal clip type things, it has 3 pipes going to it, and it needs to be assembled the same way as you took it off
In all honesty the braided pipe that comes down from the top of the engine is the hardest to remove, so what everyone does it just cut it, then connect it back on to the 710 using a jubilee clip or cable tie, I went for the tie and have not seen any bad results.
i need to change my N75 now so thats the next job...
Yes thats correct, going from underneath is the easiest option but for me, living on a hill and having a Stone pebbled drive just didnt help so I didnt fancy jacking mine up and sinking on me.lol...
I had all my bits done on Friday and what can I say, my car has been transformed....!! There is constant surge of power/boost right the way up the revs. The car doesnt hold back anymore.
I am not sure which bit did the trick but a combination of the control valve, N75 valve and higher PSI spring in the Forge DV valve has done it for me...
I am in love with my car again...!
Thanks to all you guys for you help...its highly appreciated..!
J7USS, is your car chipped? and how did you get in from the top? Do have have to take anythng out (obviously air intake). Had my DV done last week and had to go in from the bottom. Would have done it myself but like you didnt fancy the car falling on me.
Is the n75/n75j prone to failure or is the n75j just seen as an upgrade to hold boost longer?
Anyone got one for sale?
Yes my Car is Remap'd, I got in by removing my headlight, Top part of air box and pipes etc and that was it, I did catch my hand few times but them latex gloves come in handy. Id say it took me hr and half to do both but thats with a cup of coffee or two!!!
As said before I would have gone from underneath but didnt trust it and didnt want to go anywhere else.
From my experience the N75 and Uprated DV done its job with me, Improved everything and as "prel2000" has stated, It hit the button and it was like driving and getting used to a new car again.
Best bet is go on Vagparts, You'll get one dirt cheap off there.
Ive heard storys of failure of the N75,sending you into LIMP mode etc but so far so good for me and many others. Go for it mate.
Aint it brilliant mate, It does the world better. It amazes you how it does it but who's complaining hey, Its like driving a new car.
Like you say, there is no holding back anymore through the pulling stage. Thats down to the N75.
Did you go for the J or the newer K edition???? Ive heard talk of this "K" edition which someone on here mentioned they were going to try....
I remember you saying you was going to use the standard, is that the H edition..??..
Cheers J7USS, I heard about going in throught the headlight too but thought that may have been for the B5 model. I did take the two main screw out to take the headlight off but couldnt work out where to go from there.
Im having a few boost issues with my standard 1.8T (150) so not sure if I will see any performance gain unless my n75 is actualy knacked and causing the problem. Did you go for the J version? Is that the one used in the 225 TT?
Petewon - - - ....(why didnt I just use quote..lol)
Yes I went for the J version used on the TT. I had slow boost problems and it just felt lame after my remap, from a standard 163bhp to approx 205bhp was a great increase really but it felt something wasnt quite right, I went through a lot of reveiws and searching the net, even speaking to MRC and I thought for what it costs ill try a stronger DV and N75 valve, worse case would be id wasted £50odd and atleast that would have eliminated them bits and I could have moved on to the next solutions...
...but they hit the nail right bang on the head because soon as I started her up and the ecu played a few tunes for a minute or 2, I noticed a diff just by revving her up....the rest you already know.
Id say go with it mate, get yourself a N75J valve, Swap it and give it a go.. Worse case is it doesnt solve your prob and you can stick it on Fleebay and take a tenner loss!!!!
J7USS, I just went for the standard N75 in the end (058906283F), got it ordered from VAG PARTS....
I experienced the same when i started the car for the first time with the new N75, the engine seemed a little unsettled for a few seconds..
However......as soon as i pulled off for the first drive after the bits were in i just knew it was a different car. a lot smoother and so much more power right the way through the rev range. Now you can tell the car is 200+ bhp...! and I am loving every second of it...I am testing the power everytime i drive the car just to check its still there....!! Thanks for your help mate..!
No probs mate, I still do that but think im starting to get used to the power now. Ive still got to sort out my irritating Rev problem, STill holds revs for extra second or 2 when I change gear, very annoying, sounds like im keeping my foot on the accelerator whilst changing...
Does your do that???
My Golf did that,i cleaned the throttle and took the battery off for 30 mins and it was cured.Dont know which one did it or might have been both.
Cheers J7USS, Im sold. Just wondering which one to go for. Ive been reading about some issues with the J valve on standard cars and thinking I might just buy a new N75.
I've still not come any closer to finding a cure for this bloody problem.
I'm thinking maybe it's the clutch starting to slip or something?
Either way it's driving me crazy, it sounds as though I can't drive.
James, I'd be interested to find out more about this.
I sprayed loads of carb cleaner into the throttle body and gave it a good clean with a cloth.
Took the battery off for 30 mins,reconnect and then switch ign on but dont start engine,leave on for about 2 mins.The throttle made some weird noises but all was fine once i started the engine.Never had that problem again.
Yeah still no closer myself mate, Im sure mine is getting worse aswell. Really doing my nut in now.
As for the clutch theory, Ive only done 1500 on my new clutch so im guessing its not that.
Heres an interesting one for you then..... I had a new engine, Not only did it do it on this one but it did it on my last one!!!!!!
Does that help....Im lost
Yeah I still gotta try that one James.
Did you do that because it was doing the rev thing or was it just a general "ill give it a clean" sort of thing...??
As I said before, before I got a new engine, it did it, it still does it on this one. My brother, my dad and Some fancy totty eyebrows have drove it and it does it on all them. Yet I drive my mates 1.8t 52 plate FWD and it dont do it...
I hate it when I get a feeling that I wanna just get rid of my motor......I know!!!!!
It did the rev thing and sometimes wouldnt tick over properly.Been perfect for over 4 years now.
Well, I took apart the Throttle Body for standard maintenance and gave it a good clean, but it didn't seem to do much.
My car gives me so many problems. I'm getting lots of white smoke from the exhausts but it's not the head gasket apparently.
Bummer, I was hoping you was going to say it worked!!!
Im changing my Clutch Switch same time as cleaning the throttle, Kill 2 Suspect birds with one Bullet ( I dont use stones,they can bounce back )
Let us know how you get on with the clutch switch J7USS, Im getting a similar thing with mine. It feels like a realy rough change, like a bit of a jerk/thud. As if Im still too high on the throttle when changing. Does that sound familiar or totaly different?? I read somewhere abut faulty clutch switches causing this, not sure if it was this thread or not.
I did clean my TB last week and it seemed to cure it for a few hours but its back now.
Somthing I was meaning to mention was, do you need to dissconnect the battery to do a TB alignment? Ive allways just turned the keys two clicks, left it for a minute and you can hear the TB adjusting itself. Never bothered taking the battery off. Seems to work for me.
I think it doesnt really matter to be honest mate, Ive heard some do some dont regarding battery and TB.
Yes I suppose you could say your prob is the same as mine and Golf's, Mines without the thud tho, its more Accelerator and clutch press same time.."major rev".
I gave it some tonight and Ive noticed it happens even when Im sloafing along but obviously cant hear it as loud so im stuck with ideas as to what it can be.
On standstill high revving, it still takes that little longer to climb down. Cold/Warm engine is faultless but soon as its Hot, thats it, Granny foot out again, led foot!!
What Engine is yours Petewon???
Same car as yours mate, A4 1.8TQ but standard earlier 150 engine. I just dont think its running as well as it should. Im gonna change N75 and perhaps N249 and if that dont solve it Im thinking about getting rid.
Been looking for a while but realy stuck as to what to get next.
I took apart the throttle body and gave it a thorough clean, and realigned it using Vag com, but it still revs slightly when I release the accelerator. I even cleaned the airbox and MAF to no avail.
Tomorrow I'm replacing the valve cover gasket, because I'm getting nasty oil leaks and I think some is getting into the exhaust manifold. It's just one problem after the other with this bloody thing.
Hmmm why is only us quattro's that are getting it??
I was speaking to my mrs friend a while back and dont know how we got on the topic but she was saying her Bloke had same problem with his S3 - again, another quattro and in the end he sold his because he just couldnt find out what it was. The dealer told him its a common thing and you have to live with it. ******** because Id rather get rid myself.
I intend to get to the bottom of this even if it puts me on my death bed.
Id say mine is running great aprt from this problem.
I know the feeling mate, my air compressor supposed to be fu**ed and could be looking at a hefy bill.
Its true though, I always find I get everything sorted on my car (so I think) and then something comes along....If it aint anything to do with parts/srvice etc then its bloody Tax, Mot and Insurance......
...But I suppose having cars like ours its part of the contract.
Ill get the air compressor done then its time for MOT....straight after that its Service.
That white smoke thing sounds like you have one of them nut ache dilemma's.
Hope you get it sorted mate.
Sorry to resurrect an old thread j7uss, but did you get to the bottom of the revs thing? Mines a fwd as you know and it does it if i revit above 3.5k then change gear, the revs hang in the air for half a second. I wondered (since im thinking of doing an n249 delete and n75j valve & DV) if a splitter DV could be adjusted to sort that out?
Im thinking maybe its when the DV dumps boost back into the intake, does that hold the revs on at higher rpm? Just a thought. Maybe a splitter would help by dumping enough to drop the intake pressure to 0 i.e. no boost or vac, just neutral.
I did have the hanging revs thing with a vectra sri years ago, but that was the throttle control solenoid, I ended up warming the engine slightly (just off enrichment) and pulling the plug off the solenoid, thereby removing its ability to prevent stall on power steering use when cold, but then it didnt actually stall anyway so was prob a precautionary feature. It did make the engine drop snappily when the throttle was shut at any revs. The vauxhall ecu was grabbing the throttle when you let it go so as to let it down gently to idle but it messed with quick gearchanges!
And hows the valves working for ya after all this time?
Yep got it sorted in the end, found it to be the component that controls your revs above your Clutch pedal, drove me nuts, took ages to find out what was causing it. Once I changed it, it was like a whole new drive, no more hanging revs at all...
Cost me £18 if I remember rightly and that was from the Stealers..
and you know what, ive even got a part number for you 1 JO 927 189 F..:icon_thumright:
ah ha! well done mate, i'll get one o them and change it. Bloody car electronics!
If yer dvd player or tv was as unreliable as some car bits you would be shocked eh? lol
And how are the n75J and the 710 since you fitted them, no more problems? I want to do the n75j to see if it smooths the vicious boost spike i get at 2k....then the boost tails off at 2.8k and feels flat after that except a wee lift at 3.5k due to the 20v bits comin on cam
(just using my butt dyno, no gauge )
Yeah the Spring weakens inside the component and struggles to pull back to drop revs hence the "pensioners gear change & foot control" lol..
Since fitting the Valves Ive been well chuffed, I replaced the bosch with a Hyperboost recirc and that ironed it out a little further.
Defo worth doing though mate, you'll see the diff, especially when you change the piece for the annoying rev issue aswell.
i have this rev hanging problem its been pi**ing me of since i got the car. my boost is smooth all the way scots ? if yours is sharp then an n75j might make it worse
Jase, get a new Clutch Switch mate, Worth a go for £20 aint it.
I was surprised such little thing like that would cause so much grief!
Jase, you might be right, thats what i was worried about, tho its easy to change it back.
when i pull away, and say get into 2nd and open it up, then the boost (well "pull" as i dont have a BG) comes on in a vicious lump at 2k, then the turbine seems to slow down slightly as it approaches 2.5k then a wee kick again at 3k then its flat all the way to 5k, i rarely push it over 4k but sometimes have tho I never go near the redline except in "oh ****" overtaking situations if necessary - then anything goes LOL (i live in tractor, trailer and horsebox country)
will do mate ill order one today
an uprated dv might sort that out scots and your gonna need one anyway if your etting a remap
Aye thats true mate, any recommendations?
dime bar moment...
are you replacing the stock N75 for a revised N75J? is that the deal?
i have a remapped 1.8T in an A6 which sounds much like the issues you described earlier. Wherre does the N75 sit in the engine bay?
However the 710N (is that the DV?) is that the TT225 unit? i have through about this for the A6, just as a matter of course.
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