Infamous N75 Valve
#11
09-25-2009, 12:47 PM
check into the code and check the connection/wires as suggested,
do you have a boost gauge? i would get one of them asap
do you have a boost gauge? i would get one of them asap
#12
09-25-2009, 08:33 PM
I would go ahead and check the wiring and hoses that go to it before replacing it.
does that code throw a CEL?
there are people that bypass their n75 for a MBC but leave the wires plugged in and i dont *think* they have problems with it throwing codes... but i dunno. The way I understand it is that it sends a signal to the n75, but there is only two wires so there is no way for it to measure anything it does, it just a valve. Therefore it wouldnt be able to tell its bad. Now that I think about it I guess maybe if its totally fried it then it could give you a code for an open circuit, cuz that would be just like unplugging it?
try searching around some more for that code number:
17956
Boost Pressure Regulation Valve Open Circuit.
P1548
and see if you can find some more info on what can cause that just to be sure
does that code throw a CEL?
there are people that bypass their n75 for a MBC but leave the wires plugged in and i dont *think* they have problems with it throwing codes... but i dunno. The way I understand it is that it sends a signal to the n75, but there is only two wires so there is no way for it to measure anything it does, it just a valve. Therefore it wouldnt be able to tell its bad. Now that I think about it I guess maybe if its totally fried it then it could give you a code for an open circuit, cuz that would be just like unplugging it?
try searching around some more for that code number:
17956
Boost Pressure Regulation Valve Open Circuit.
P1548
and see if you can find some more info on what can cause that just to be sure
#13
09-25-2009, 08:34 PM
Do you have a boost gauge you'd recommend?
#15
09-26-2009, 04:06 PM
MBC = mass boost controller, ive never messed with one
in terms of boost gauges, i have an AutoMeter which is decent, a lot of people use VDO
According to the Bently manual it looks like you need: VAS 5051 or VAG 1551 scan tool to peform a check of the valves actuation, but you can check the internal resistance between the two pins on the valve with a multimeter, it should be between 25 and 35 ohms
in terms of boost gauges, i have an AutoMeter which is decent, a lot of people use VDO
According to the Bently manual it looks like you need: VAS 5051 or VAG 1551 scan tool to peform a check of the valves actuation, but you can check the internal resistance between the two pins on the valve with a multimeter, it should be between 25 and 35 ohms
#16
09-26-2009, 05:08 PM
Whats a good place to pick up the VDO?
That includes all the needed accessories to hook it up.
Also, Whats a good pod distributor? and what other gauges would be good on an audi?
That includes all the needed accessories to hook it up.
Also, Whats a good pod distributor? and what other gauges would be good on an audi?
#17
09-27-2009, 10:42 AM
You don't necessarily need a pod, a lot of guys put their boost gauge in one of the vents. JC did a really clean install on the vent next to the driver's door. Obviously the downside there is that you have to hack up one of your vents, and if you muck it up its gonna look terrible. In that same vein, I've seen gauge pods that replace the entire vent, which looks pretty cool. Lemme see if i can dig up some pics and i'll edit this post to include them.
EDIT: My mistake, JC did a triple gauge pillar pod install: https://www.audiforums.com/forum/alb...pictureid=6394
I'll see what else I can find.
EDIT: My mistake, JC did a triple gauge pillar pod install: https://www.audiforums.com/forum/alb...pictureid=6394
I'll see what else I can find.
Last edited by CCA4; 09-27-2009 at 10:46 AM.
#18
09-27-2009, 12:29 PM
yeah thats actually exactly what i was looking for.
What are the other gauges that he has? Like what else is necessary?
I didnt want to hack up my vent.
What are the other gauges that he has? Like what else is necessary?
I didnt want to hack up my vent.
#20
09-28-2009, 01:37 AM
mbc is manual boost controller as opposed to an electric one. i have a vdo boost gauge that replaces my center vent and it is red so it matches the dash lights.
http://shop.achtuning.com/browseprod...and-B5-S4.HTML
you could probably get it at a better price i got mine from a local tuner for a little cheaper, but it looks good and you dont have to tear anything up, and you can always replace the vent if you want to go back. if you are going for the 3 gauges you could do an air/fuel ratio gauge and maybe an oil pressure?
http://shop.achtuning.com/browseprod...and-B5-S4.HTML
you could probably get it at a better price i got mine from a local tuner for a little cheaper, but it looks good and you dont have to tear anything up, and you can always replace the vent if you want to go back. if you are going for the 3 gauges you could do an air/fuel ratio gauge and maybe an oil pressure?