werid boosting fault?

[dan2252]

hello my 1.8t agu has started holding back its werid how it does it.. ive got a boost gauge and were watching it earlyer i floored it taking it round in 2nd and then to 6 k in 3rd and i was reallly struggling in 3rd to make it rev, the boost goes up fairly slowly then upto 15 psi then backs off then climbs to 21 and does not budge, where as normaly it slowly climbs and drops back to around 17 and goes real well!  a 3 cylinder polo would be faster than my car when it goes into crazy mode! haha ive fitted a new n75 valve... it doesnt do it all the time either i then tried giving it some 10 or so min after and it went back to normal! werid!!

[cullygti]

have you checked all pipes on pcv system for leaks

[dan2252]

whats best way to check them mate? ive had a visual check of them but cant see nothing clearly leaking

[inggti]

Sorry t jump in but Pcv?? It's just it sounds a little like my problem

[xxChrisxx]

whats best way to check them mate? ive had a visual check of them but cant see nothing clearly leaking

Take the PCV valve out and blow through it both ways.
If you can... it's knackered.

Also the pipes split on the bottom side, so you have to take them out to see properly.


It shouldn't really cause major problems on boost though, a slight hint of rough running and lost economy at lower speeds and slow to switch to overrun I've found.

[cullygti]

usually and i say that sparingly its the pipe under neath the inlet manifold there is a small black rubber pipe and it splits mine was broken and i didnt know for months until it completly lost all power check them from inlet mani right through from oil filter housing and on the side of rocker cover if it is damaged you may be better off fitting a oil catch can  

[cullygti]

take a look at the pipes in the thread they are usually whats split
http://www.golfgtiforum.co.uk/index.php?topic=230053.0

[dan2252]

cheers lads! thanks for the quick and very good replys! right just nipped out to the car in the dark and noticed the pipe that goes on the side of the rocker at the right hand side isnt fully on and has turned all nasty and werid! like the oils eaten into it? plus wont push back on like its gone smaller? haha never noticed it before! would this do it you rekon?

[xxChrisxx]

All those hoses perish, when you take it off in the cold light of day, you'll find little balls of rubber and that the wall thickness is lower.

They are fairly expensive from the dealers (that little right angle piece is £13), it's probably cheaper trying to source some silicone hoses.

[cullygti]

try these but depends on your engine code a lot of ppl use crm including myself 
http://www.ebay.co.uk/itm/AUDI-TT-A31-8T-20V-180-BHP-SILCONE-BREATHER-HOSE-AUM-AUQ-AWW-AWU-AWP-AWD-/160779960686?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item256f3b816e