WGFV & Diverter Valves low boost

[iain1067]

Folks

what are the symptoms of these items failing, after spending the last few days messing with my urs4 and failing to find to it's missing boost runs 1.7 on the gauge should be more like 2.0 or 2.1bar. i am pretty sure i don't have any leaks and have replaced the michelin man hose on the intercooler just for good measure. I have cleaned the diverter valve,wgfv,inlet air temp sensor, replaced a few suspect hose clips on the crankcase vent system, checked the wastegate diaphragm (no splits or tears), replaced the hose clips on the moisture trap.

I am sure someone has messed with the wastegate in the past because i found under the spring seat a thin nut and the screw is quite well turned down maybe 8-10mm, obviously a sign of someone elses attempts to cure this problem. I have also ran the ecu output checks with a jumper wire, all the relevant parts buzzed at me even the wgfv but i guess this may not tell me that it's toast. Oh and why change to the S3 type of diverter valve??

Where else should i start looking??

Thanks

Iain

[4WheelDrifter]

I've just changed the A3 DV to an S3 (710N). The old one had got very loud and was chattering. I hear that the S3 DV has never been known to fail. Plus it was only £17 from my local Audi dealer.
HTH

[GandalfS6]

I hear that the S3 DV has never been known to fail.

My mates with S3's have them failing every 5000 km! But they are better than the S2 / RS2 TBV!

[4WheelDrifter]

I now hear different then. So I'll still keep my eye (ears) on it then.
It's a good job they're cheap, and easy to replace.

[GandalfS6]

@4WheelDrifter - Don't worry - we live at extreme conditions at 5000 feet above sea level and temps up tp 40 in summer (right now). I actually think it is the heat that gets to them - on the S3 they are very close to the turbo. My wife's 944 T has more or less the same Bosch DV and being placed further from the turbo it has lasted 10 years!