3b turbo leak

[teejay]

Hi just got the car back after engine rebuild and i have got turbo leak.
To start from the beginning.... When i got it back it was with standard ecu and it was cutting out at around 4000 rpm and waste was opening at 0.4-0.5bar.
Changed ecu for the chipped one and it suppose to allow 1.2.
after the change it is reving perfect but waste is still opening at 0.4 thats spring rate. Ecu underpressure hose is connected dont know if it not blocked thoug.do not know if plaing with the wate will help.any ideas what shall i check?
Thanks.

[K Simmonds]

Start by pulling the fault codes, however if your only getting spring pressure then it would suggest a problem with the N75, there should be no need to adjust the wastegate.

[teejay]

Just to make things easier would you tell me please where is it located and if there is any way of checking it?
What color and is disconecting will do anything?

[teejay]

Got the location.disconnected it and it is the same.will try to take it off and clean it and see then whats happening...will try ecu pipe for blockage.....

[teejay]

Yesterday i took n75 out cleand it and put some wd40.when engine is running it is clicking on when connected but after a second or two its clinging off on idle.is it normal? What should be next thing to check? Underpressure connections to ecu?

[newsh]

You need to do a boost leak test.
Also try disconnecting the MFTS , the big sensor under the middle of the water manifold.

[Quattronaut]

The motor is completely stock? Then for failure search you should use the stock ecu.

How do you know it is boost leak, do you hear it? 0,4-0,5 bar is emergeny program, which is the same as driving without N75. This can be caused by defect N75, defect MFTS, defect IAT sensor and a couple of other things. First I would try is a boost leak test. Things like the N75 I would not check or measure, better try another one that is proven to work.

[Error404]

boost leak check, check MFTS. Check knock sensors.

[UrS4boy]

3B, ABY, AAN and ADU Boost leak testing

S2 3B and ABY and RS2 ADU Boost Leak Testing:

http://www.s2forum.com/forum/showthread.php?t=63974&highlight=3b+boost+leak

[teejay]

Thanks guys.will try to do the boost leak check.disconnecting mfts didnt help.
Let me say that before i took my car to have engine rebuild it was running perfect apart from smoking blue when hot ( valve stem seals cured it but decided to do it all in one go ) on standard ecu. When i collected the car ( 6 weeks later ) it was cuuting off at around 4000rpm,the turbo was blowing up to 0.5 max and then you could hear blow off opening droping the pressuee and building it again up to 0.5 when accelerating steady.
Today is the day i am going to take it back there and leave it with them untill it is in the same state as before.
I was waiting 3 yers to have it on the road so you can imagine how dissapointed i am...

[teejay]

Just came bk from holls.collected the cat from fitters and guess what.it is as it was.nothing changed.i have got boost gauge and it is going nicely to around 0.4bar then pressure is going down and up when trying to hold it steady.it will go over 0.4 but going higher you can hear the noise like air leak or like pressure is going through crack or gap.don't know if they pressure tested the system but all they said is when they were pulling the codes n75 was causing the problem. I ordered new one and waiting for delivery.
do not know anymore if can trust them and would like to have second opinion so maybe anybody from around wales or west mids will have a time to have a look and discuss the cause over the weekend?

[SteveH]

Sounds like a boost leak if you can hear air escaping. They have probably left a hose clip loose or perhaps a split in one of the hoses. Both are really common problems and easy to check with some bungs and a compressor. Try that and then disconnect/check the other sensors already mentioned. I'm in Bristol if you want a hand.

[teejay]

Thanks for reply. Problem is finding time to do the check.got too much stuff going on at the mo.
I do think it is leaking from some hoses as you said as if I'm correct if the blow off was opening too soon I would not hear it like that.hopefully will have a minute during the weekend and will check it by hand and eye for loose bands.

[K Simmonds]

That does sound very much like a boost leak, which garage did you use, one in Hereford or elsewhere?

I'm 30 miles away from Hereford and could pull the codes and do a leak test tomorrow afternoon as long as it's dry It doesn't take long to conduct the test and most leaks are easy enough to address as long no hoses are split.

I'd also stick with the stock ECU until the car is running properly.

[teejay]

Hi.sorry.just had a look on forum.bit too late for that.....
I think it is a boost leak somewhere alongvthe way.will put standard ecu tomorrow after work.i can come and see you next weekend if that ok with you.