Wanted: N75 Boost Control Valve etc - Page 2

geneandbolly · 19-06-14, 11:32 AM

yup, this photo here looks pretty much like mine - a lot of big blanks in there . . is that it?? i was expecting to see loads of fuses in there . .

https://www.google.co.uk/search?q=ur...0%3B1000%3B775

K Simmonds · 19-06-14, 05:32 PM

It's worth noting that the engine speed sensor fault code will always be there unless it's cleared with the engine running, if the speed sensor is in fact faulty I very much doubt you'd be able to start the car. The speed sensor code will reappear after each restart as it's triggered as soon as you turn on the ignition with a static engine.

The hesitation sound like coil packs or the associated low tension wiring.

ISV and N75 are indeed on the same fuse.

martinws · 19-06-14, 06:33 PM

Check fuses for sure Craig and get rid of the bleed off valve that is inline with the lower wastegate hose and the N75 then give it a shot again.

K Simmonds · 19-06-14, 06:40 PM

Ahh, there was no mention of a bleed valve before now, their dreadful things, get rid of it ASAP! Seriously though that really isn't the way to go about getting more from these engines, it could also be causing the N75 fault.

Martc · 19-06-14, 07:01 PM

Quote:

Originally Posted by geneandbolly

yup, this photo here looks pretty much like mine - a lot of big blanks in there . . is that it?? i was expecting to see loads of fuses in there . .

https://www.google.co.uk/search?q=ur...0%3B1000%3B775

Yes that's under the bonnet and there is hardly anything there

The main fuse panel is on the end of the drivers side of the dashboard behind a half moon shaped panel

http://12v.org/urs/RHDDriversEndDash...owingFuses.jpg

Andy10v · 19-06-14, 09:56 PM

Would the bleed valve not cause a code as the ecu is not seeing the boost it specifies?

Get the bleed valve off, and once the car is running properly get a proper 285bhp chipset, not expensive and will transform the car.

K Simmonds · 19-06-14, 10:10 PM

Yep, that's what I was thinking, the MAP sensor is going to be seeing more boost than is specified for a given throttle position, hence the N75 fault code.

geneandbolly · 19-06-14, 11:54 PM

thanks for your suggestions, chaps. martin spotted that bleed valve thing and i'll get that removed asap and take it from there. will be interesting to see if there's any improvement once that's sorted. as for the fuse box, both ends of the dash stated "danger - airbag" so the fuse box definitely isn't housed there. all i can see is that half empty relay box under the driver's wiper arm area.

Martc · 20-06-14, 09:19 AM

Quote:

Originally Posted by geneandbolly

as for the fuse box, both ends of the dash stated "danger - airbag" so the fuse box definitely isn't housed there. all i can see is that half empty relay box under the driver's wiper arm area.

Trust me it is!

My cover has that message on it too, the message has nothing to do with the cover on the drivers side, its just a handy place for Audi to place their H&S warnings.

At the bottom of the cover there is a cutout, that is where you can get something in to open the cover for the fuse panel.

Error404 · 20-06-14, 10:56 AM

S6 fuses are behind the cover on the end of the dash - check the ISV & N75 fuse, AFAIK the N80 is on that fuse too, so I'd expect a code from that too if the fuse was blown.
I agree with the above - get rid of that bleed valve AKA detonation device ASAP and then reset the ECU and recheck codes. If the ECU detects too much boost AFAIK it will pull the timing anyway so bleed valve is useless on these motors, leave them for the rice kids and their tonka toy turbo set-ups.

19-06-14, 11:32 AM	#11
geneandbolly 4 ring whore! Classic Audi Club Member Join Date: Sep 2011 Location: The Psychiatric Ward, North Ayrshire Posts: 7,490	yup, this photo here looks pretty much like mine - a lot of big blanks in there . . is *that* it?? i was expecting to see *loads* of fuses in there . . https://www.google.co.uk/search?q=ur...0%3B1000%3B775 __________________ 1997 Audi S6 Ruby Red Last edited by geneandbolly; 19-06-14 at 11:34 AM.

19-06-14, 09:56 PM	#16
Andy10v Grown up member Classic Audi Club Member Join Date: Dec 2008 Location: Stirling Posts: 861	Would the bleed valve not cause a code as the ecu is not seeing the boost it specifies? Get the bleed valve off, and once the car is running properly get a proper 285bhp chipset, not expensive and will transform the car. __________________ 2005 350z GT Sold-1992 3B S2 coupe-RS2+, 996s, konis, forged rods, rear torsen.... Sold-1993 ABY coupe

19-06-14, 11:54 PM	#18
geneandbolly 4 ring whore! Classic Audi Club Member Join Date: Sep 2011 Location: The Psychiatric Ward, North Ayrshire Posts: 7,490	thanks for your suggestions, chaps. martin spotted that bleed valve thing and i'll get that removed asap and take it from there. will be interesting to see if there's any improvement once that's sorted. as for the fuse box, both ends of the dash stated "danger - airbag" so the fuse box definitely isn't housed there. all i can see is that half empty relay box under the driver's wiper arm area. __________________ 1997 Audi S6 Ruby Red

19-06-14, 05:32 PM	#12
K Simmonds Senior Member Classic Audi Club Member Join Date: Dec 2009 Location: Mid Wales Posts: 1,060	It's worth noting that the engine speed sensor fault code will always be there unless it's cleared with the engine running, if the speed sensor is in fact faulty I very much doubt you'd be able to start the car. The speed sensor code will reappear after each restart as it's triggered as soon as you turn on the ignition with a static engine. The hesitation sound like coil packs or the associated low tension wiring. ISV and N75 are indeed on the same fuse.

19-06-14, 06:33 PM	#13
martinws Grown up member Classic Audi Club Member Join Date: Sep 2009 Location: Johnstone Posts: 723	Check fuses for sure Craig and get rid of the bleed off valve that is inline with the lower wastegate hose and the N75 then give it a shot again.

19-06-14, 06:40 PM	#14
K Simmonds Senior Member Classic Audi Club Member Join Date: Dec 2009 Location: Mid Wales Posts: 1,060	Ahh, there was no mention of a bleed valve before now, their dreadful things, get rid of it ASAP! Seriously though that really isn't the way to go about getting more from these engines, it could also be causing the N75 fault.

19-06-14, 10:10 PM	#17
K Simmonds Senior Member Classic Audi Club Member Join Date: Dec 2009 Location: Mid Wales Posts: 1,060	Yep, that's what I was thinking, the MAP sensor is going to be seeing more boost than is specified for a given throttle position, hence the N75 fault code.

20-06-14, 10:56 AM	#20
Error404 Thobbing Member Classic Audi Club Member Join Date: Sep 2008 Location: Staffs Posts: 490	S6 fuses are behind the cover on the end of the dash - check the ISV & N75 fuse, AFAIK the N80 is on that fuse too, so I'd expect a code from that too if the fuse was blown. I agree with the above - get rid of that bleed valve AKA detonation device ASAP and then reset the ECU and recheck codes. If the ECU detects too much boost AFAIK it will pull the timing anyway so bleed valve is useless on these motors, leave them for the rice kids and their tonka toy turbo set-ups.