0.7 bar on stage 2 lc... starting to loose my patience.

[jamie1]

Right, have a stage 2 lc. Had it mapped about 3-4 months ago by amd, all was fine.

About a month ago i realised i thought i had some sort of boost leak as the boost would peak at 1.4 bar and drop off very quick down to around .5 bar.

I did a boost leak test and checked ALL vacuum lines and boost pipes etc and found no leaks or splits.

Was using a 007 with yellow spring. I inspected and serviced the dv with no change and even tried another one but was still the same.

I also tried a friends standard n75. (was using a j valve, which it was mapped with), but was still the same. The boost would peak at 1.4 and drop off very quick. I cant guarantee that the borrowed n75 was working properly as my friend has no boost gauge but were pretty sure its working fine.

Anyway, i brought a brand new n75J, tried it, and still no difference!

Over a period of about 2 weeks i have noticed that from boosting to 1.4 and dropping off, it will only boost to 0.7. This would happenn intermittently.

But, recently when full boost is requested it will only boost to 0.7 bar,no more, which is standard boost and holds it fine?!

But like i said, iv noticed that over a period of 2 weeks that the boost has been getting worse, even to the point where i am now where it wont boost any more than .7 bar. Its as if something has been breaking down, but what??

Im not sure if it could be down to the map possibly? I dont think it is but it could be a possibility? Iv tried a new n75j, but have read that some maps dont agree with these sorts of valves?

Unfortunatley i dont have vag-com so cant record logs which sucks as i know it would help me out but cant get it so thats out the question..

Can anyone shed some light please as im loosing patience with it big time now!

Thanks!

 

[seatcupramad23]

take back to amd i'd say

 

[IanTheBiker]

When I had a boost leak I was getting a huge spike for the turbo trying to compensate the loss but of boost I changed my N75 valve for a 1 out of a ttrs and still spiked its nutts off...

in the end it was a tiny little pipe that was coming off the intake manifold to the going to the N249 valve the ugly box on the rocker cover.
Replaced the pipe and that sorted that issue... which led me to a full engine rebuild lol
boost gets you laid baby and you know this !!

 

[jamie1]

n249 is bypassed and had been removed before the map.

 

[IanTheBiker]

Well if its not a leak or the N75 or the dv I carnt really see hoe the map could fall progressively over the days so there not much left to look at to be fair apart from the expensive part lol the big T check the actuator nut has not came lose have you changed the pipe at the end of the intake the brake vacuum hose that splits on all S3s making a huge boost leak ..

boost gets you laid baby and you know this !!

 

[rk696]

Your car is going into soft limp mode. You really need to get it hooked up to vagcom and see what's going on.

My Octy vRS used to do this, it boosted fine to 18 PSI, then dropped it to about 8 PSI. It was like someone had put the brakes on. Does it do it at random, or do you need to do somethign to trigger it. It could be anything - Excessive inlet temps, boost leak, overboost, misfire, loads of stuff it could be.

I'd take it back to AMD. They should be able to do some logging to find out what it is.

 

[armo]

Is this the first map the car has had from standard?