How to: N249 Bypass - AMK/BAM Engine

BenJee_S3

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I Thought I'd do a little guide on the N249 bypass for the AMK and BAM engine which is different (and more simple) than the bypass on other engine codes.

The AMK/BAM engines dont have an N112 valve, which means there's no need to cut and t-piece anything. It's as simple as putting silicon vacuum hose from the DV to the inlet.

All that's needed is some 4mm internal diameter vacuum hose and new hose clips. I bought 2 meters on eBay for about 4 quid all in.

So remove engine cover to expose the mess that is this:

Vac chamber and N249 spaghetti junction...
This is what we will be removing:

20130826_091854.jpg


So undo the bolts which attach the vac chamber to the metal bracket and release the valve from the catch.


Follow the pipe to the dump valve and disconnect:

20130826_091856.jpg


20130826_100129.jpg


Now remove the plastic cover down near the dipstick which is secured with 2 Phillips screws.
This reveals a metal plate underneath which is removed with 2 Allen key bolts.

Follow the vac pipe from the N249 down to the inlet and disconnect. This can be found on the left of the inlet manifold on the underside:
Here:

20130826_100123.jpg



Dont forget to disconnect the electrical valve. Once disconnected pull out and keep aside:


20130826_100140.jpg



Once out the car, disconnect the piping to salvage the valve:

20130826_101027.jpg


Despite bypassing this valve, we still need to keep it electrically connect otherwise the ecu will throw up an error code.

I re connected the valve and tucked it away behind some heat proof to hide it.

Now disconnect the metal bracket which is bolted to the cam cover

20130826_092351.jpg


The bay should now look like this (ignore the fact my coils are out, I changed my plugs whilst I was at it)

20130826_100135.jpg


Now all that's left is to connect the dump valve to the inlet with the 4mm Vac hose. I used small cable ties to run the hose the route I wanted:

20130826_113750.jpg


And that's it! Re assemble the bracket near the inlet and the plastic cover and it should look like this:

20130826_113757.jpg


Since doing this my DV seems a bit more responsive, makes a slightly different noise and keeps the bay nice and neat!

Hopefully this will help some fellow AMK/BAM owners as this was a lot easier than first thought.
 
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Good work... added to stickies (as I live in hope someone will read them one day...) :)

<tuffty/>
 
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What is the benefit of removing this.

Generally speaking it removes clutter, less pipes to rot and split and improves the response of the DV...

The flip side is that the ECU loses a control feature for dumping boost if it feels it needs to... not a massive issue as the ECU also controls the throttle so can close that too...

On higher power setups it serves no real purpose and is removed along with PCV deletes etc...

<tuffty/>
 
ahh good, nice to see a guide for the BAM engine, been meaning to do this but figuring it out from other guides was just confusing matters! i'll get some hose and get on it sometime soon :)
 
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Great guide, something that Im going to have a shot at this weekend, and given Ive got an AMK this is prefect, thanks!
 
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Hey, just finished this on my BAM. Thank you very much!
 
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Would a slightly larger (5mm internal diameter) hose affect the function of this at all? I might do this tomorrow, so would only be able to buy from Halfrauds...
 
Would a slightly larger (5mm internal diameter) hose affect the function of this at all? I might do this tomorrow, so would only be able to buy from Halfrauds...

Only if its too big for the relevant nipples... 5mm maybe a bit loose

<tuffty/>
 
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Cheers chap. I might hunt around the shops to find some, failing that do it another time.

Problem is you have decided you want to do it tomorrow, so it WILL happen! Once things are in my head. ..
 
just done this. dv sounds so much better, and bay looks a hell of a lot tidier :)
 
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Will do this to mine over the weekend I think too.

Thanks for the guide!

I'm using 5mm silicone vac hose, will just nip the jubilee clips up a bit more!
 
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I fancy doing this today but can only get 5mm or 3.2mm vacuum hose. What would you guys suggest is better. And am i reading this right i need to fit it to the dv to the inlet manifold. Refit the valve . Nothing else? Just to clarify because im useless. Thanks
 
Great guide just done this to my S3 last week.
 
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I fancy doing this today but can only get 5mm or 3.2mm vacuum hose. What would you guys suggest is better. And am i reading this right i need to fit it to the dv to the inlet manifold. Refit the valve . Nothing else? Just to clarify because im useless. Thanks

I would go for 5 out of the 2, but ideally 4mm is best. I'm sure I got mine from eBay really cheap.

Yep that's it mate, as long as its an AMK or BAM engine code that's all you need to do!
 
I would go for 5 out of the 2, but ideally 4mm is best. I'm sure I got mine from eBay really cheap.

Yep that's it mate, as long as its an AMK or BAM engine code that's all you need to do!


Ok ill get some ordered in 4mm. Id rather have it right. Thanks for the reply.
 
Uploadfromtaptalk1390135573383 did mine today due to a slight leak on one of the pipes on the valve. Sharpened up the dv dump noise no end. Before it was like pssshhhhhh. Now its PSTT.
Thanks for the guide.
 
So you don't have too connect any vacuum pipes too the valve just the electrical connector and that's it?
 
So you don't have too connect any vacuum pipes too the valve just the electrical connector and that's it?

That's right. One pipe from the underside of the manifold to the top of the dv.
 
Got my pipe for this just need time to do it. washed the car instead :) so will do it next weekend if its nice
 
Just done this and the car won't start haha! Anybody else had this and can help?
 
Pics? Have you re connected all electrics?
 
Did you reconnect the plug back into the bottom of the intake manifold? I almost forgot to do it.
 
All plugs were plugged back in the pipe that's part of the PVC system has snapped! So it is taped up and cable tied until I can get 1 tomorrow it's the vacuums that go from the left side of the inlet it's the bottom pipe that has snapped going into another pipe?
 
It was this pipe that has went

Anyone know where I can get 1?
 
Just done this to my s3 today was so easy following this thread well chuffed with the end result. ImageImage
 
I did mine the other week, how did you get on with attaching pipe to standard dv ?
Mine didn't seem to work too well as I couldn't get the screw driver very low. Ended up with a cable tie on first as I could pull it tight, then hose clip that felt like it was being pushed of as I tightened it.
Dave
 
I had to put the mounting plate back on to the head because I wanted to put the cover back on, and the other tab has broken on the cover, so without it would have meant no cover support apart from at the front.
Dave
 
Done yesterday, thanks for the 'how to' great help

pujapyqu.jpg
 

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