Maybe Loosing Boost

[Mat]

Came a different way home from work today, and as I got near home, I was on a back road with footdown. Dunno what made me look at the bost gauge, but I noticed it was at 15psi and wouldn't go up. So changed gears (both up and down) and still didn't go above 15psi....

Only just noticed this, but I'm sure it was ok on way to pod on Sunday as I had fun on the way

Usually will boost right up to 25psi.

Also, service light is on. Had crossed my mind if there was a "safe/service" mode, but realised that the light has been on for just over a week....

Can't physically hear any leaks (any hissing etc), turbo and spooling sounds all ok. The EML hasn't popped up.

May go test it tonight or 2moz on my way out

Suggestions?

 

[SeanyK]

25psi sounds high... Is it a k03s / Stage 2 map?

My Jabba map boosts to 20psi.

Does the car still feel as fast?

 

[Mat]

felt quick yeah.... always been that high TBH! K03 with CC Stage1

 

[SeanyK]

Blimey thats high! Bet it's pretty quick!

I guess if no codes are coming up, check connections to the boost gauge, check the t-piece.

I'd say N75, but it'd be quite noticeable, same with a MAF fault, even if they didn't post up an EML, the car would feel sluggish.

Limp mode would be very low psi

 

[Mat]

Mmmm.... now you mention it, i took the T-Piece out last week to paint the exposed bit red. Best check that really

 

[SeanyK]

It's worth a check now if you have time, give it a quick look take it out for a drive and check and let us know

 

[L9 GOW]

once you get it fixed never go that way home again

 

[arron2004]

Blimey thats high! Bet it's pretty quick!

I guess if no codes are coming up, check connections to the boost gauge, check the t-piece.

I'd say N75, but it'd be quite noticeable, same with a MAF fault, even if they didn't post up an EML, the car would feel sluggish.

Limp mode would be very low psi

where is the best place to pick up a N75 over the web ?

 

[Mat]

bloody wont! had to use a different filling station. Also caught attention of new under cover fuzz car! lost them in traffic, and then later noticed was low on boost LMAO

 

[Mat]

off out to check and then go play and see

 

[SeanyK]

where is the best place to pick up a N75 over the web ?

http://www.premier-tuning.co.uk/oe-genuine-18t-n75-j-valve-9-p.asp

Thats for a 'J' valve, but you can get C's or F's too.

Although in fairness mate, your better off ringing your local Audi dealership if you want J version, and giving them 034906283J part number.

 

[Mat]

Right then, just been out and checked the T piece. All is ok.

Went for a drive, heated up fairly quickly (think I need more coolant ). Booted it in 3rd, at around 3-3.5k it peaked to 15-16max then dropped at around 4k (not normal). Did same in 5th, but proper lost boost, rapid loss.

Pulled over, looked at bay, pushed and nuged this that and other and I think I found the problem.

Heard a small "hissss" from back on engine. Nudged tip near air filter and it changed to more of a hiss. Nudged along various parts, near DV etc and gets louder around there. Wont boost about 5psi now lol. Guess I know what I have to do 2moz (luckily my day off). Check all clips and connections!

I hate cars

 

[cuprachrissy]

I hate cars

you know you love em!!! whats the difference with n75j valve to the normal one?

 

[Mat]

stronger IIRC

 

[Reuvers]

you know you love em!!! whats the difference with n75j valve to the normal one?

J will most likely cause problems.
however some people have luck with them and get slightly more boost.
I guess if you're willing to spend money on something that might very well cause problems, then feel free.
If not get the regular one

 

[Reuvers]

oh and mat, what do you mean with the 'service light'?

we have one of those, indicating the car needs to be serviced?

I do my own servicing and have had the car for over a year and a half, and never seen such a light?

 

[SeanyK]

Ah, well it doesn't sound too bad a problem mate, just a loose connection somewhere, check the dump valve is seated properly with all 3 connections tightly secured.
Also check the pipes coming off the boost pipe to the N75. There are 3 pipes going into the N75, check both ends are connected tightly.
Might be the top vacuum off the dump valve.

Cuprachrissy> The N75 'J' valve is meant to boost a little higher than the standard C or F valves. I had a C valve on mine, before it went wrong, so just replaced it to a J valve, runs lovely!

 

[cuprachrissy]

Cuprachrissy> The N75 'J' valve is meant to boost a little higher than the standard C or F valves. I had a C valve on mine, before it went wrong, so just replaced it to a J valve, runs lovely!

ok nice one, what vac pipes go where on the n75 valve bud? my car is off the road and i just changed turbo, etc. removed all my vac pipes too so dont know where they go back

 

[Mat]

yes Dutch man, the service indicator that comes up on ignition where it shows mileage. Me and a mate will be doin a service on it soon

 

[SeanyK]

ok nice one, what vac pipes go where on the n75 valve bud? my car is off the road and i just changed turbo, etc. removed all my vac pipes too so dont know where they go back

Hi mate,

Well if you have a forge TIP, one part (the longest part) of the N75 goes into the side of that, the other part comes from the boost pipe to the bottom part of the N75, and the other one goes from a vacuum pipe leading down to the turbo/actuator area (into the left of the N75).