Why do my engine revs rise

[Paulm]

I has just started to do this. When i change gear my engine revs rise 3 or 4 hundred rpm then go down again. It idles fine and goes fine. I have done a search but could not find much

Paul

[S2 Ant]

try taking ur foot off the accelerator when u change gear

[audiman]

Soak your idle speed control valve in some duck oil, sounds like that is clogged up with breather fumes.

[GandalfS6]

It sounds to me like your DV is going. The plastic Bosch DV thingies we have in our cars don't seem to last that long. I have a Forge DVR which will hopefully last forever (you just change the diaphrams). A new DV is GBP 20 from www.vagparts.com.

[Paulm]

S2 Ant will try that next time

ok will look at Idle Valve and DV

cheers

Paul

[horvathg]

Hi Paul,

mine does something similar recently. I could say it does the same. I wanted to remove the idle valve but gave up when saw how well it was fixed to the case with some rubber tubes.....And what is DV plz?:wacked:

[Paulm]

DV = dump Valve, some call it blow off valve or recirculate valve. It dumps boost when u lift off the throttle. I have not looked for mine yet but on my coupe it was easier to get at from under the car.

Paul

[GandalfS6]

Have a look at http://www.s2-audi.co.uk/tech_articl...ve_replace.htm for a good guide on how to replace a DV.

[horvathg]

Thank you guys, a great description. I'll check out if it works.

[GandalfS6]

The thanks goes to Mike - he has a very nice site!

Paulm - if it is your DV you might find the car going much better. A faulty DV would loose boost! BTW my friends with S3's have huge problems with DV's - they seem to only last 6 months in our heat and on the S3 it is situated very close to the turbo. They loose lots of performance when the DV goes.

[i love scooby snacks]

While on the subject, does anyone know where I can get an atmospheric dump valve for a 3b from? Ive heard them on some of the vids on here but cant find anywhere in the UK that sells them.

(Sorry to those who think they're tacky boy races gimmicks that should not be used on anyhting other than an R5 Gtt or RS turbo, lol)

[audiman]

You cant find one as there is no one that sells a kit. I had one on my car for a while. Far too noisy and it made the car stall all the time. It also has to be relocated into the upper boost pipe, the one above the exhaust manifold.

IMHO dont bother, it also makes the turbo take longer to spool up than the std DV after a gear change. Car is quicker with std one in original position.

[GandalfS6]

If you want to get one GFB is quite good and can be adjusted to dump more or less air to the atmosphere. I have seen their DV's and they are very well made.

It is apparently not a good idea to use one as it confuses the ECU which is thinking that the DV recirculates. I assume you could reprogram the ECU to accept a recirculating DV.

Anyway, on www.gfb.com.au it says that www.grahamgoode.com stocks GFB.

HKS also makes a dump to air valve. I have heard one and it is quite loud.