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revs rise during gear change

Posted: Mon May 10, 2010 8:32 pm
by Imol4vant
Hi guys,

Proud new owner of RS4 B5 and new to the forum.

I have owned the car for about 2 weeks and have noticed a problem when changing gears. If I'm using full throttle and change gear in the higher rev range the engine speed increases when the throttle is off and the clutch pedal is down. In the next gear I then have to wait for the turbos to recharge before getting back into projectile mode.
It seems to me that the turbo pressure is not being released, so is still giving boost to the engine and trying to stall the turbos all at the same time.
It has a full Miltec and a remap but have never known mods like this to cause the symptoms above.

The car, now in Scotland, is the Yellow one with the Nurbugring on the back, that used to be spotted around Swindon.

http://www.rs246.com/index.php?name=PNp ... ic&t=82595

I think it was for sale for such a long time because it was waiting for me.

If anyone has any ideas about the problem or knows any of the history of this car I would be very pleased to hear from you.

Hello again and thanks for listening.

Imol4vant

RE: revs rise during gear change

Posted: Mon May 10, 2010 8:55 pm
by jimbo1234567
get it on vagcom, rev rise will be down to a clutch pedal switch, boost will be due to diverter valves , change them for 710n,s if they havent been done already, change the maf too.

RE: revs rise during gear change

Posted: Mon May 10, 2010 9:15 pm
by Imol4vant
Thanks very much for your response.
Sorry for the ignorance but could you spell it out for me please.

RE: revs rise during gear change

Posted: Mon May 10, 2010 9:20 pm
by davs4
710N's are sited under middle engine cover (the one with the writing on) either side of engine.
MAF is the part near air box with a clip in the side.
VAGCOM diagnostic sotware.

RE: revs rise during gear change

Posted: Mon May 10, 2010 10:30 pm
by Imol4vant
Thanks, I'll look under the bonnet tomorrow.
Had a quick look on Ebay for VAGCOM, seems to be quite a choice. Are some better then others?
Does the clutch pedal switch tell the ECU to cut the power?

RE: revs rise during gear change

Posted: Tue May 11, 2010 9:55 pm
by jimbo1234567
get a genuine rosstech lead and yes it does cut the power. the fault will show up on a scan had exactly the same problem with a mates car a few weeks ago. there are a few scottish owners on audisrs who will happily help you out if you ask and get no joy here.jimbo :nogarors4:

RE: revs rise during gear change

Posted: Wed May 12, 2010 4:42 pm
by Imol4vant
Had a look yesterday. Did the switch the old fashioned way. Took bottom dash cover off, stuck my head under, pulled connector and tested it. Works as a switch should. Pedal up circuit, pedal down no circuit.
Took one of the DV's off, black pressed steel, no markings or part no's, also I could spin the two halves of the casing. I geuss this is a sealed unit and the crimp should be tight enough to hold both halves toghether as if one piece.
Had a look on ebay and found photo of dv's with part no 06A 145 710n. Same shape but look like moulded plastic. Asked at Audi today today, They came up with 034145 710b. Asked to look at S3 and they up with same part No. as Ebay, only cheaper and no P&P. Is this the right one?
If the MAF needs replaced do I replaced it with one for my car or is there an upgraded version of this also?
Rosstech leads, are they much the same price everywhere or is there someplace you recommend.
Thanks for your help,
Imol4vant

RE: revs rise during gear change

Posted: Wed May 12, 2010 4:53 pm
by mikeyquattro
You want the 710n DV's as they have a stronger diaphram than the 710b's.

Order Vag-com direct from http://www.ross-tech.com/

Star Performance in Kirkcaldy will be able to look after most of your needs if you're in the Fife area?

RE: revs rise during gear change

Posted: Wed May 12, 2010 5:11 pm
by SJS
You want 2 of the 710N valves as they are the most reliable. If your old ones spin they must be apr valves. Clean them up and stick them on ebay.

RE: revs rise during gear change

Posted: Thu May 13, 2010 2:18 pm
by Nige_RS4
Metal casing suggests an aftermarket DV - replace them with 710N as mentioned above?

RE: revs rise during gear change

Posted: Thu May 13, 2010 4:42 pm
by simon_golf_tt
Where in Scotland are you Imol4vant, I'm in Fife and have Vagcom. I wouldn't mind scanning your car if that helps you. I also have an RS4.

Posted: Thu May 13, 2010 6:23 pm
by Imol4vant
Thanks again guys,
Seems pretty unanimous my DV's have got to go, so have ordered two from Audi today. Will pick them up on Monday morning and stick them in.
Here are photos of what is fitted, pressed steel, no markings.

Image

Image

I'm in Edinburgh and would love to get my car plugged in.

Posted: Fri May 14, 2010 9:23 am
by simon_golf_tt
I'm only 15 miles from Edinburgh, so if you'd like it scanned with vagcom, PM me and you can pop over some time.

Posted: Fri May 14, 2010 2:32 pm
by ABU10
Off topic: your rs4 looks mad on the pic

Posted: Wed Jun 09, 2010 10:00 pm
by Imol4vant
Thanks Jimbo for the advice,

Fitted 710's on the Monday seemed a bit better but not cured. Had a look at the air filter, very dirty, got new one, better again but not cured. I went to see simon_golf_tt and got Vagcom'd. No faults.

Thanks very much Simon.

The car did lose the "launched into hyperspace" feel, is this because the turbos were surging and giving to much boost?

Fitted a new Maf two days ago. That fixed it. More torque, smoother, more MPG and sounds happier. Still not feeling as brutal, but no revs rising.