Sai removal guide

jonny87

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well as promised, heres my guide to removing the sai on the s3, first off i apologise for the lack of detailed pitures, i got half way through the job and realised i had forgot to take any, so ive done my best to highlight the important bits with things removed

DSC00173.jpg


also i would reccommend that you do the n249 bypass before doing this mod, makes sense really

things you will need:
blanking plate (http://www.forgemotorsport.co.uk/content.asp?inc=product&cat=010201TUN&product=FMEGRBP)
coolant (i ended up completley draining my system)
10w 330 ohm resistors x2 (see http://cpc.farnell.com/welwyn/wh5-330r-ji/resistor-10w-5-330r/dp/RE04125?Ntt=10w330ohmresistor)
10mm spanner
5, 6 &8mm allen keys (must be ball ended)
socket set
soldering iron (for resistors)
an extra pair of hands always comes in handy

time taken:
well it took me and my mate absolutley ages to do this, we hit a few problems such as a bolt being rounded off that secured the combi valave to the block and we didnt have a couple of necessary tools so had to improvise, but if all had gone well i would of said 2 - 3 hours

right here we go:
first off jack up the front of the car and get your axle stands under there, the higher up you can get the car, the easier you will find it to work under there! if you have the plastic undertray remove these (i took mine off a while ago and never refitted them)

get underneath and look to the drivers side inbetween the oil filter and auxillery belt and you will see the sai pump we are removing, there should be an electrical plug connected, pull this out and put it to one side for now.

now look down into the engine bay from above, remove the braided hose from your combi valave that goes to the n112 valve and now you can remove the metal plate that holds the n112 valve (put this to one side, we will come back to it later) now you can trace the two black hoses down to the pump, one will go from your airbox to the pump and the other will go from your combi valve, disconnect these from the pump (i found it easier to do from above but can be done from underneath too) if you are unsure how to do this disconnect the one from the combi valve first, just squeeze the two ribbed sides of the clip together and pull, it will take some force but it will go, once disconnected both hoses are clipped in place about half way along their length, find these clips and undo them then the pipes are free to be pulled out.

pipeoncombivalve.jpg


now get back under the car, at this point i would reccommend you wear some safety specs, in and around the pump is very ****** and i got all manner of crap in my eyes but its up to you, there are 3 10mm nuts securing the pump to the bracket, two of them are easy, the third not so but it can be got at, just a bit fiddly, now your pump is loose but i bet you cant get it out, right?

bottombolts.jpg


look at the end of the pump where you disconnected the electrical plug, there should 3 plastic tabs spaced around the diameter of the pump, these are easy to undo, get these off and that end of the pump will come away from the main body, there is a plastic bush and spring in there so watch it dont catch you in the face! inside theres two wires connected up to the motor by spade connectors, pull these off.

pumpclips.jpg

saipumpapart.jpg


now the pump still wont come out of the bracket at this point but you have just given yourself alot more room and manoveability! you should now be able to see two 8mm cap head bolts at the bottom of the bracket, jiggle the pump around to give the best access possible and get these undone, this is fiddly but keep at it, once they are cracked off they will come out by hand.

bottombolts.jpg


now you got two choices, depending on whether you got a mate to lend a hand or not, if you do then both get under the car and have your mate pull the bracket towards the oil filter (its a strong old bracket so dont be scared of giving it some welly) while you jiggle the pump around, theres a rubber hose on the aux belt side that gets in the way, you need to bend this as much as poss and slide the pump past it, trust me give it some force and you will get the pump out this way (this is how i done it) also if you choose to go this route you have the option of leaving the bracket in situ i.e you need not struggle to get the top bolt undone, just replace one of the bottom bolts to stop it vibrating

bracketandhose.jpg


the second option is to undo the top bolt that secures the bracket, looking from above again, the bolt is inbetween where the thermostat is housed and the oil dipstick, a ball ended allen key or flexi drive is essential for this as the dipstick tube prevents you from getting in there square on (be careful not to round the head off) get this bolt undone and the whole thing will fall out the bottom, simples!

topbolt.jpg


which ever way you decide to do it you will now have removed the pump, its bracket (unless you leave it in of course) and the two plastic pipes, now to be fair you have done the hard bits so have yourself a break!

all work now will be carried out from above, now if i were you i would drain the coolant system it saves getting coolant all over your bay and garage floor and is just easier imo but its up to you, whilst draining, remove your airbox and engine covers (if you havent already)

now you can see where your combi valave connects to the block and you can see the coolant pipe which is blocking access to the two bolts, so get that out the way and it is possible that you may have to disconnect the plastic coolant pipe from the block too (if you do take care there is a rubber 'o' ring seal in there dont damage it or lose it)

bplatefitted.jpg


before fitting your blanking plate i cleaned up the surface of the block using some fine emery cloth just to ensure a nice clean seal, then fit your blanking plate, replace whatever coolant pipes you removed and refill/top up your coolant system (if you drained it remeber to bleed all the air out they system)

now going back to your n112 valve, nothing needs to be connected to this anymore and so can be removed from the plate completly, although if you cant be bothered no one will see it and it can be left there, makes no odds really, the hose that runs from your dv used to lead to the n112 and inlet manifold now only needs to go to the inlet manifold, all i done is to modify my existing tee piece that i put in when i done the n249 bypass

n112valveremoved.jpg

siliconehose.jpg


now all thats left to do is to fit your two resistors, one will go in the wiring for the sai pump (trace this wiring you should be able to pull this up into the bay save you trying to solder under the car) and the other will go in the wiring for the n112 valve, easy enough, snip the connectors off, strip the insulation back and solder the wires onto the resistors, cover in insulation tape and you're done!!

if plugged into vagcom you will get an improper flow fault from the pump, but if like mine yours was knackered in the first place then you would of got this fault before removing it, other than that you should have no codes, no warning lights etc

DSC00148.jpg


please note this is a guide, i cant take any responsibility for any damage done/caused by following this guide, this is exactly how i done it and i have had no problems at all.

please leave feedback if following this guide as to where you think others may benefit from additional information, thanks
 
Cheers for the how to. I think I must have been struggling to remove the pump (2 of the bolts that held it to the bracket had sheared off and it was banging around) as you were writing it up. Getting the pump out of the bracket appeared completely impossible (although I didn't think of trying to dismantle the pump) so I went the bracket removal route which was merely almost impossible! At least I now know that I needn't try and fit it back again, I can just rip out all the cheap pipework attached to it.
 
yes mate its not the easiest of jobs to do, i cant understand why they made the pump so inaccessable

i will probably remove the bracket at a later date but like i said we didnt really have anything to get at that top bolt and id spent 2 hours trying to remove a rounded off bolt and by then was well and truly ****** off lol
 
electrical tape lol

its a quick fix as i plan on using it as a caf

if i was going to block it off i would fibreglass it from the inside
 
Nice write up!
Does the car feel/respond different?

thanks!
na, there are no gains to be had from this 'mod' except saving yourself a few kg in weight

if you get an error code on vagcom regarding the sai its more than likey ********, easier and cheaper to remove than replace

it doesnt do alot when it is working properly and audi never fitted these on the bam & amk engines (probably realised they were a waste of time)
 
LOL , just seen this dude! I did mine whilst engine was out.... what fun.....

Did you do hat on my drive? It looks exactly the same!!
 
probably would have been easier to have taken the engine out to do it lol

yes mate, i popped round whilst you were at work and done it ;)
although its probably much more likely that we have the same block paving?? lol :)
 
mentioned this to someone today and they said the secondary air system is there to feed oxygen into the exhaust system for when your starting your car from cold, apparently the car running richer(from cold) means more unburnt fuel enters the exhaust system and can potentially damage the CAT - the pumped oxygen helps break down the unburnt fuel and therefore helps save the CAT - not sure why the BAM or AMK's dont have it though..........

anyone have any views regards this? - would like to confirm before making the effort to remove what could be a useful item

Tim
 
I was told by a friend that it's used to heat the front of the cat quickly so that the cat works more efficiently in a shorter period of time, either way it's a useless bit of kit that we could do without. I wonder how much the lower part of the BAM / AMK airbox costs? It would look much more oem than having to tape the hole up. I spoke to one of the lads at R-Tec who are looking at writing the SAI out of the map so you get no DTC's, apparently not an easy job to do but I'm sure they will work their magic and get it sorted soon.
 
na it wont heat it surely...... there would have to be an element in it...... i dont want to remove it if its task is to save the CAT
 
oh man that is boring :)

although confirms what we both said, the oxygen reacting with the unburnt fuel on start up helps the fuel to break down and helps the CAT, also gets the operating temp of the exhuast system up quickly to ensure the system itself remains tiptop :)

im not removing it...... wonder why the BAM and AMK's didnt have it :/
 
might be soemthing to do with the valve timing or some additional gear we dont know about - im defo not removing it from the AUM for now unless someone comes up with a definative answer - neighbour was saying they cost a fortune which is prob why the mod became 'famous'
 
It's 'famously expensive' to repair or replace some parts, hence why some people want to remove them (that's the reason why I want to remove mine, my pump is noisy when it runs so I want to get rid before it breaks down). Makes for a tidier bay too when removed :icon_thumright:.
 
i done some research on the sai before removing too, i read that its there purely to meet emissions regulations even when running rich at first start up which audi are required to do by which ever governing body etc etc yawn yawn

i hardly think its going to destroy the cat, god knows how long mine hadnt been working for as it was full of water/mud/grass/general ***** and mine has passed emissions test on every mot cert i have for the car, the fact that bam/amk doesnt have the sai says to me that audi discovered that they are friggin useless and break easily and so done away with them, thats my train of thought anyway

as for getting the sai coded out, you could do this if you were really picky and bothered about it, ive had mine removed for well over a month now, no lights on dash but obviously if plugged into vagcom you will get improper flow or similar code thrown up but you will know why, just get two resistors, much easier imo
 
Just a note to all.

Leave the N112 valve electrically connected, if not fitting a resistor.

If you don't, this can stop adaptive fueling from working resulting in HIGH EMISSIONS and MOT failure.

Like me. LOL. :icon_thumright:
 
Need a little more info on soldering in the resisters?

cut off the electrical plug for n112 valve, strip the wires back a little, solder in resistor (330 ohm iirc) and cover in electrical tape, i also put a resistor in where the plug for the sai was but left my n249 connected, had my car plugged in last weekend, showed no faults at all

welly had problems with his because he hadnt left the valves connected nor had he soldered in resistors, we think this was confusing the ecu (badger bill explained this in a much more professional manor in wellys mot thread) and caused his emissions to be all over the shop, retest tomorrow isnt it welly?
 
Can you leave the pump in place so you don't have to solder any resistors in, and just remove the pipes etc,.

Yes.

And to be fair, getting the pump out is no joke at all. getting the bracket off the face of the engine is an even bigger PITA.
 
What would happen if I didnt put a resistor in for the SAI and just removed it all and left the plug there not attached
 
Thats all I've done and no problems so far. The only side effect I've seen is high idle 1200ish on cold start but that sttles down to normal after 20/30 seconds
 
3 months or so, i keep meaning to solder in resistors but one of cars always needs something more important doing! pretty sure someone will tell you not to do this but not had any big issues
 
Help lol. Im trying to fit the 'O' ring back in the coolant pipe. It seems too big to fit on the inside lip of the pipe.
 
Hmm, my SAI has just caused an EML (or the rear lambda sensor) on my VCDS. Is it worth removing and fitting my decat at the same time? My MOT is due in Janaury, so if I put the cat back on will the EML come back and will it pass the MOT with an EML? I've done the N249 bypass and now it's freezing outside it seems time to work on the car....(as usual)..
 
Yes.

And to be fair, getting the pump out is no joke at all. getting the bracket off the face of the engine is an even bigger PITA.

I think I'm just going to leave the pump in place too, so without doing all of that, I just remove the plastic pipes and fit the blanking plate? Should be much easier....(famous last words..)
 

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