boost control valve

[Jay sx]

Hi All, Fault code is flagging up boost control valve fault on my 240 tfsi cupra. Has anyone replaced one of these , its only a small thingy but after rolling around under the car I've come to the conclusion that its going to be a total pain. Any tips from anyone who's done one would be much appreciated.

 

[R3k1355]

Boost control valve is the N75 valve, fairly easy to replace.

 

[Jay sx]

Yes I believe the code relates to the waste gate controller ( N75 valve ) Is the diverter valve the dump valve ? R3k1355 , have you changed one, Access from the top looks very limited and not much better from underneath. Haven't receive part yet but will endeavour to have a bash then, cheers.

 

[R3k1355]

No, I've only done one on a Diesel Mk2 Leon, 5 minute job. Probs not what you wanna hear, but it is literally just bolted to the top of the firewall.

Have you logged boost vs requested boost on VCDS??
Thats what showed mine was broken, it was asking for boost but only getting 50% of requested.

 

[Jay sx]

Haven't got VCDS , friend at work has some fancy reader (cost 1600 apparently) I'm getting P2261 08801 boost pressure control valve (mechanical malfunction) After searching the net I`ve narrowed it down to the N75 or the N249 ( which is the diverter valve I believe) Im trying the cheapest first . I have rising revs at idle which seems to be a common problem but very hard to get a definitive cure. Changed the PCV valve , no joy so had the fault read.

 

[Hawkers]

Haven't got VCDS , friend at work has some fancy reader (cost 1600 apparently) I'm getting P2261 08801 boost pressure control valve (mechanical malfunction) After searching the net I`ve narrowed it down to the N75 or the N249 ( which is the diverter valve I believe) Im trying the cheapest first . I have rising revs at idle which seems to be a common problem but very hard to get a definitive cure. Changed the PCV valve , no joy so had the fault read.

How does the car drive at full throttle, any issues with boosting?

 

[Jay sx]

Car doesn't really feel any different than normal. Only noticed because the revs started going up and down when idling , only when car is up to temp. Have checked for vacuum leaks but cant seem to find anything.

 

[Hawkers]

Rising revs at idle is most definitely an air leak somewhere, have you got an aftermarket air intake? Check all hoses you can, under the car etc. I would say PCV but you've replaced that..

You could try taking out your dipstick with the engine running and if it doesn't start running rough then would suggest PCV.

The thing that has me wondering is generally the N75 valve and diverter valve regulate turbo boost, so you come into issues when pressing on with the car and requesting boost which the car can't maintain, common issue is for the DV to split and leak boost causing performance issues. Here's a guide on the DV http://www.mk5golfgti.co.uk/forum/index.php?topic=87824.0

 

[Jay sx]

Thanks for the information. Am going to change both valves, double check hoses , fit new (another) pcv and take it from there. Hopefully this problem wont beat me lol