boost problem

[wannabeS4]

I have a boost problem. I have stfa and didnt find the answer I was looking for. I have pressure tested. I boost 5-6 psi in all gears.

I found a leak on the brake booster line where the line creates a T. Another thing is when Im stopped at idle my vacuum reads 21 but when Im driving it reads 24. I also have my cel light on. Would the leak in the brake booster cause these readings.

[mholme]

Are you chipped or stock? You need to know what the CEL is for, you could be in limp mode because of it. A leaky brake booster hose is a common area for leaks.

[wannabeS4]

im stock, and I have a vag com cable in the mail so i will know shortly. I thought limp mode was limited to 5psi.

[mholme]

im stock, and I have a vag com cable in the mail so i will know shortly. I thought limp mode was limited to 5psi.

Limp is like 5-6psi max. Maybe someone in your area can scan the car for you, an autozone or the like could also do it.

[wannabeS4]

I will have to check out autozone to see if they can scan the car. What would cause the change in vacuum?

[mholme]

What would cause the change in vacuum?

A leak, probably

[s42k5b]

DING DING Correct answer^^

[adr3naline fix]

What do you normally boost at?

N75 valve clear? Unplug it and drive for a bit. If you boost above that6psi it may be your N75. Remember to not go WOT when it is unplugged

MAD dirty/bad? Try running without it, if problem persists, it's not your MAF

[wannabeS4]

Ok so something new, went wot today and saw that I was boosting over 15psi, the boost levels would fluctuate from 11 to 18 psi. Im thinking it may have something to do with the n75 valve. How can I tell if thats bad?

[S-Power]

Its your N75 bro, I have the same problem, I talked to Jay at JHM about this a while ago and he also said its the N75

[wannabeS4]

alright cool, is that an easy fix.

[highPSI-S4]

3rd item listed. You might be able to find it somewhere cheaper, but yeah it is an easy fix

http://www.ecstuning.com/stage/edpd/...ategory=Engine

[00s4slvr]

wait you said you were stock?? Your obviously not stock and chipped because stock boost levels are 8-9psi while chipped could vary from 15-16 with spikes to 18-19...

[gointoscott]

before you order the n75 i'd wait and get it vag'd to see what codes you are actually throwing.

if you have an intermittant egt sensor that is bad it will throw your car into limp mode and will boost sometimes at 5-6psi when in limp mode and other times it will boost normal. This also fits the description of your problem.

[Caddy7]

Is there no way of logging the EGT's readings??

[mholme]

Is there no way of logging the EGT's readings??

Sure, block 112. They should read 1035 engine off and 945 with the car running. Anything else and they are going bad.

[ThirdStrike]

3rd item listed. You might be able to find it somewhere cheaper, but yeah it is an easy fix

http://www.ecstuning.com/stage/edpd/...ategory=Engine

cant believe you pointed him to the stock valve. the 'H' Valve is a MUCH better solution and on ecs is even cheaper right now.
http://www.ecstuning.com/stage/edpd/...l=&engine=2.7T
another link to it with the part #
http://www.worldimpex.com/parts/genu...id_117475.html
op; im gonna co-sign on the 75 valve being bad.

[highPSI-S4]

cant believe you pointed him to the stock valve. the 'H' Valve is a MUCH better solution and on ecs is even cheaper right now.
http://www.ecstuning.com/stage/edpd/...l=&engine=2.7T
another link to it with the part #
http://www.worldimpex.com/parts/genu...id_117475.html
op; im gonna co-sign on the 75 valve being bad.

H valve? Your talking bout the N75 race valve right. I thought there was a thread awhile ago about. Alot of people that bought that H valve returned it cause there car would boost to high or something. For k03's the stock N75 valve should be good.

[ThirdStrike]

H valve? Your talking bout the N75 race valve right. I thought there was a thread awhile ago about. Alot of people that bought that H valve returned it cause there car would boost to high or something. For k03's the stock N75 valve should be good.

the higher spike is what the valve was designed to do. if you dont like higher spikes then run a mbc in parallel. i still say H valve is better. stock turbos or not. this is my experience, not based off what others said..

[Caddy7]

Sure, block 112. They should read 1035 engine off and 945 with the car running. Anything else and they are going bad.

Thanks, is there a way to log the N75 also?

[mholme]

Thanks, is there a way to log the N75 also?

119

[wannabeS4]

wait you said you were stock?? Your obviously not stock and chipped because stock boost levels are 8-9psi while chipped could vary from 15-16 with spikes to 18-19...

My boost doesnt always hit the same psi, sometimes it hits 12psi and some times and I can hit 18psi, so Im pretty sure Im not chipped, wish I was. Well once I get my vag com cable I will scan it. I do have a cel light on so I am throwing a code. It should be a couple days.

[highPSI-S4]

My boost doesnt always hit the same psi, sometimes it hits 12psi and some times and I can hit 18psi, so Im pretty sure Im not chipped, wish I was. Well once I get my vag com cable I will scan it. I do have a cel light on so I am throwing a code. It should be a couple days.

What he's saying is if you weren't chipped you should only be hitting 8-9 psi max and maybe a 10psi spike. but if your boost is any higher than that you def. are chipped. 18psi meens you are chipped. Might want to try and find out what software you have.

[wannabeS4]

So what your saying is if I was stock and my n75 valve was bad I would still only be boosting 8-9psi.

[S-Power]

So what your saying is if I was stock and my n75 valve was bad I would still only be boosting 8-9psi.

Exaclty

[wannabeS4]

So Im chipped!!!!! so the n75 valve would cause the boost to fluctuate. How would I go about finding out what software I have.

[Caddy7]

119

Do you happen to know what walues is normal?

[00s4slvr]

First of all i told you that if your over 8-9 psi then your chipped way back in the thread lol. Second it seems like your n75 valve is bad cause i had a similar issue exact mine would hold 15 spike to 18 then drop to 12 then back up to 15 and continue. Bought a new STOCK n75 valve and that fixed the problem.

About finding out what software you have, My money is on giac.
Since you said you bought a Vag cable download the giac flashloader for free. Try reading and if the flashloader reads then you have a giac chip. If that doesnt work then try to hold the set button on the cruise control stalk and hold it for about 7 seconds and if the check engine light blinks then you have apr software.

As for other tuners im not sure how to go about that. Maybe take the ecu out and see if there is a tuners sticker on it??

[mholme]

Do you happen to know what walues is normal?

Nope. You actually have to log requested vs actual boost as well at the same time to tell if it's doing it's job. Here's some diagnostic info:

http://s4wiki.com/wiki/N75

[Caddy7]

Nope. You actually have to log requested vs actual boost as well at the same time to tell if it's doing it's job. Here's some diagnostic info:

http://s4wiki.com/wiki/N75

NICE!!! that was some good reading right there.

[wannabeS4]

well its not apr and there were no stickers on the ecu, so my guess is on giac.
where is the best place to order the valve from

[mholme]

well its apr and there were no stickers on the ecu, so my guess is on giac.
where is the best place to order the valve from

What..and what? Did you get the car scanned for the code(s) yet?

[wannabeS4]

no I havent scanned it yet, why?

[mholme]

no I havent scanned it yet, why?

Because your CEL is on? You probably want to know what the code is for before throwing money at the car.

[wannabeS4]

well I wasnt going to buy it yet just doing some research.

[mholme]

well I wasnt going to buy it yet just doing some research.

Just going by what you said in your previous post. Get the codes read first..

[wannabeS4]

Ok so here are the codes that came up when I vag my car

17755 - Camshaft Position Sensor 2 (G163) / Engine Speed Sensor (G28): Incor. Correl.
P1347 - 35-10 - - - Intermittent
17535 - Fuel Trim - Bank 1 (multi) system too rich
P1127 - 35-10 - Intermittent
16486 - 16486 - Mass Air Flow Sensor (G70): Signal too Low
P0102 - 35-10 - Intermittent

Also the giac flashloader program didnt work. So now it is just a guessing game to find out what chip I have.

[wannabeS4]

after I cleared the codes and went for a drive. The cel came back on and I scanned it again and the only code that came up was the 17755 camshaft sensor 2/ engine speed sensor