n75 issues

[CCCupra]

I have had boosting issues since getting my car, i feel a surge in power when i put my foot down but it doesn't seem to like holding the boost.

While replacing some pipes that looked worse for wear, the N75 actually snapped off. I had been told it could be a faulty n75 too, so i bought a new one.

Fitted it today, now say I'm in 3rd, I can put my foot down, ill get a lot of boost, then non, then a lot, then non. Like every other second i get boost and then it goes!

Faulty new N75? Should I get the codes cleared first?

 

[DrewCole]

I would advise getting the codes read and cleared first of all yes.

Do you know if you still have the factory recirc valve or has it been replaced? Reason for asking is the factory ones do fail so could be dumping boost with the diagram flapping open and shut.

 

[CCCupra]

Ill get them cleared tonight. Its all standard, so I'm guessing its on the original recirc.

 

[DrewCole]

My one is still running the OEM valve and it has just started to dump whilst on boost, which is annoying!

87k miles.

Going to change it for a piston type one.

 

[CCCupra]

Ah really? Mines on 130! Any recommendations? Shall i just get a new OEM one?

 

[cookie225]

Have you got the right N75 , there's a letter after the numbers, each letter N75 needs to match the same letter as your broken one is set up different for the boost

 

[CCCupra]

Its 058906283C - so the same as the old one isn't it?

 

[cookie225]

If the old one is a c the new one must be a c Aswell,

 

[ibizacupra]

dont just randomly buy things fella..
DV is most unlikely to be your boost fluctuation/cause..

UNLESS, it chirps on gear change in which case its probably split.

Unplug your maf and see if the pulsing boost goes away.
If not then find yourself someone who can do a smoke leak test for you...

Throwing parts at it randomly is going to cost you more than it needs to...

 

[CCCupra]

Well id rather not! But if they go at 80, then surely my 130k car is due one..

Its not chirping, just pulsing boost, never experienced anything like it.

Ill unplug the maf tonight if clearing the codes doesn't solve it, see how we get on.

Thanks for the help.

 

[ibizacupra]

what codes if any does it have?

 

[CCCupra]

Ok so I've got the following codes:

16795/P0411/001041 - Secondary Air Injection System: Incorrect Flow Detected
17963/P1555 - Boost Pressure Control: Upper Limit Exceeded
16487/P0103/000259 - Mass Air Flow (MAF) (G70): Signal too High

Cleared them, still exactly the same.

Ive just noticed, my old N75 ends with F, not C

 

[cookie225]

You need a f then, good chance I will solve it

 

[CCCupra]

Just read that the "e" version is a better and revised version of the f. Should I give it a try?

 

[cookie225]

Yh that's what I had to do with mine tbh get the newer type an It sorted out my boost problem, get an original one tho not a copy off ebay

 

[CCCupra]

Yeah bought a genuine E now.

We will see how that one goes!

 

[CCCupra]

Thought I would update the thread.

So I just fitted the E n75 valve now, without clearing the codes etc as I won't have a reader till later on.

The problem with the boost surging and losing pressure while at the same throttle position seems to be gone, but I'm still not happy with how it holds boost, It seems to have a nice bit of torque when I accelerate, but just doesn't have that "turbo" feel in the higher revs (even though i can hear the turbo).

It is totally standard, is this normal behaviour?

My previous turbo car was an Octavia VRS with the same motor (AUQ) but did have an exhaust and induction, but it boosted and held the boost throughout the entire rev range.

 

[ibizacupra]

std - turbos the size of a dolls hair dryer

 

[CCCupra]

Fair enough, does feel better after clearing the codes though, maybe the best it's been but I may be imagining it.

 

[ferriss1]

im getting the same also AUQ i dont have any fault codes tho.......