Just bought a 2001 1.8T and have been reading on here for a couple of days about various problems etc.
One of the things that keeps cropping up is the stock recirc dumpvalve (or boost diverter as it seems to be called in VAG circles) not being good enough and leaking off boost. Now, why do people need to replace them? I kept reading about this and was aware of what they looked like (same as the old cossie ones) and I've had evos in the past where the boost bleeds off on WOT due to the valve not being able to hold anymore. The cure was to reverse the stock valve on the evo and on boost it holds the valve shut instead of trying to blow it open.
I popped the cover off the golf last night and thought I'd reverse the stock valve just incase it wasn't holding boost and they are allready reversed as standard on these engines (which makes more sense to me) I've had cossies, evo's 944 turbo etc and they all have a similar design valve but the other way round so they leak off boost on WOT higher rpms.
So basically the stock VAG valve is already fitted so when the car is on boost it actually pushes shut rather than blowing open.
What all the above waffle is getting at is why do loads of threads on here mention changing them to stop boost problems? It looks like the way they are fitted they'll hold ok on boost?
Or do they fail in some other way? Not that I can see how as they are pretty basic and a good blow into it will see if it's sealing.
Reason I've been looking at these sort of threads is because the golf I bought developed a terrible flat feeling to it's performance, I know these engines like a MAF so bought a new Bosch MAF, cleaned the TB, bought some new Bosch Platinum spark plugs and got tinkering.
The car now idles and runs smooth as silk and doesn't have the flat feeling (like an anchor suddenly gets dropped lol) BUT the boost comes in hard at around 2krpm and you think ooh, this is fruity then it's like the power doesn't build and just feels a bit sluggish to how you think it's going to be. I realise it's only 150bhp but the way the turbo comes in is like getting foreplay from the mrs and thinking here we go, then she gets up and fooks off! The car seems to run ok now but the way these VAG engines deliver the power is very frustrating IMO I had a cupra 20v T a few years ago and the golf has brought back the memories of the power delivery.
Been thinking of a remap but does it actually make the car feel fast over 3krpm? I don't just want an amplified version of the stock MAP ie hit at 2krpm then a crawl to the redline.
My engine is the AUM engine and I've read it'll remap to 220bhp if it's got the k03-s turbo? sods law it'll be the k03 turbo though so that'll mean 190bhp?
Is there anyway of easily finding out what turbo is on the car? it doesn't look too easy to see any codes due to the position! The car is a 2001 if that helps.
