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Discussion Starter #1 (Edited)
EDIT:
Thanks to Photobucket we can no longer host images 3rd party. Please send me a PM with your email for a guide and I will forward you a PDF of these instructions. File is 8MB for anyone who may have a solution to post onto this thread as an attachment.


This is a guide that is intended for informational purposes only. What you do to your vehicle is not my responsibility nor the responsibility of this website. Proceed at your own comfort level.

This was performed on a 2009 S5. Build date May 09.

I am going to try to explain this as best as I can. I did a few things that didn't need to be done, but I had no idea what exactly I had to do. I will attempt to compile ONLY the steps required to do this job (the way I plan on doing it next time, with lessons learned in hand); however, if I skip a step or something is unclear, please let me know. I will update the OP as necessary.

I did not compile a "tools required" for this job. If you are attempting this, you probably have all of the tools required for the job. This is no easy task.

Here we go:

Remove the fuel line running from the tank to the distribution block.



2 screws hold the distribution block to the car. Remove them. Also remove the electrical plug.



Remove the RH hose clamp. DO NOT worry about the LH clamp. The rubber hose will come out with the distribution block.



Follow the fuel line from the distribution block to the LH pump. There is a clamp and a line attached to the pump. Remove both. Pull the distribution block from the engine and set aside.



Pulling the intake. Remove sensor wire and 2 clips connecting the intake tube to the filter box.



Follow the intake tube up to the throttle body and remove all hoses that are clipped to the tube. Remove clamp and vacuum line as shown.



Additional connector must be removed as well. Be careful with this (I broke mine :wall:)



Close-up.



Removed.



Remove the tube from the car and set it aside.

Continued.
 

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Discussion Starter #2
Remove electrical connector on throttle body.



Close up.



4 screws to free the throttle body. Please count 4. There is 1 hidden from this view. Bottom left (of image).



Separate carefully.



This is how I remember what hardware goes where. Place them where they belong!



The PCV system on this car is fragile and unfriendly. I tried to remove it with the intake manifold and ended up breaking a piece. $100 later I want to avoid this headache for you. I apologize if these instructions are unclear. This path is a "theoretical best way" and should be followed with caution.

Remove these 2 screws. DO NOT worry about the hoses attached. They will stay in the car.
WARNING: This adapter is $100 to replace and is very fragile. There is a tube that sits inside of the intake tract that you will need to pull away from.
These screws are very hard to reach and you will have your patience tested.



Separated. Again, see how these two parts fit together.



To the front of the engine. Remove 16 (I think, please double check) screws that hold the upper intake manifold. 1 of these will also hold a clamp for the fuel lines going to the RH fuel pump.



Remove 2 of these.



Fish the shroud up and place it aside.



Start prying up on the engine using your weapon of choice. I used a long flathead screwdriver. You're going to feel bad thinking your hurting your baby. Just be gentle. Move around from one spot to the next. She'll give eventually. DO NOT try pulling the intake yet. There are still things connected. We just need to gain access to them.

Continued.
 

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Discussion Starter #3
Remove this connector (front right of engine).



As you lift. Remove this line.



There's one more line buried deep. I pulled my intake out without knowing about it. Thankfully nothing broke.

This line.



Connects to the open line at the middle right of this image (lower right of the engine bay).



Set the upper intake manifold aside. Sit back and look at the glory. BUT you're not done yet.



Removing lower intake manifolds.



Remove the screws that cover the lower intake manifold. I think there are 4 down low and 5 up high. DO NOT REMOVE YET!



There are two of these little buggers you need to remove first.



Pull from the car and set aside. Do the same for the opposite side.



Remove this fuel line to free the fuel rails. Same for the opposite side.



Continued.
 

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Discussion Starter #4 (Edited)
Remove connectors attached to your injectors. Pull on the fuel rail and the lower intake manifolds at the same time. They are interlocked. Some injectors will come out with the rail. Some will not. DO NOT pull the lower intake manifold too far. There are electrical connectors still attached.



Connectors.



You now have access to the partitions. Pull them with pliers.



Look at your ugly carbon buildup.



Test your injectors for resistance. Mine all read 2.0 OHMS.



SEND OUT YOUR INJECTORS TO BE CLEANED PROFESSIONALLY

I cannot stress this enough. This is something that you will have to perform at your own risk if you choose to do this yourself. I did not feel comfortable rigging a machine to pulse my injectors as they move fluid. $10 per injector for a professional is worth it, to me.

Cleaning valves.

I tried GM top engine cleaner and was only disappointed. The following method works best.

Buy a portable media blaster that is capable of blowing walnut shells. Buy WD-40 (but you probably already have this). Get a lot of shop towels. Buy a bore cleaner brush (gun dept. at your favorite shopping center).

Step 1. Spray some WD-40 into the valve to ensure that it is closes. If it is not closed, stuff a towel in it an move to the next. I believe 6 valves are closed at one time. 2 are open but do this step for ALL cylinders.

Step 2. Remove WD-40 to the best of your ability using towels.

Step 3. Blast with walnut shells. This makes a mess. Try your best to hold a shop vacuum near the ports to catch as much as you can. This is a two handed job.

Step 4. Using compressed air, blow out the walnut shells.

Step 5. Spray with WD-40 and scrub with gun brush. Soak up with towel.

Repeat steps 3-5 until you are satisfied with your valves. Do this for each cylinder.

Marvel in awe at your clean valves.

NOTE: This was after a walnut spray. Use WD-40 to remove walnut dust.

 

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Discussion Starter #5 (Edited)
OH... Assembly is opposite of removal :running:

Just a word of advice to remove the manifold bolts in the correct sequence and to tighten them to the correct torques and to replace the gaskets.

ELSAWIN:



Tightening sequence for intake manifold

– Tighten bolts for intake manifold in the sequence -1 to 10-.

t Tighten initially to 8 Nm

t Subsequently tighten to 9 Nm and then tighten 90° further
 

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Discussion Starter #7
I'll try to clean this up with some arrows and circles and what not to help show what to do but I need to get my car back together! I hate waiting on parts!
 

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Super guide for a common problem on the S5 V8! Thank you for all the details.

When cleaning I assume it is very importat to make sure the vales are closed to not get durt in to the cylinders. How did you check this and turn the engine to make it all closed?
 

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Discussion Starter #9
I checked to make sure cylinders were closed by visual inspection followed by a small spray of WD-40 to make sure nothing leaks through.

To move the valves, I had a helper pull the car while it was in gear. Just make sure you have your injectors or spark plugs pulled to let air through on the cylinders that are on a compression stroke.

Don't panic if some walnut pieces get into the cylinder. They won't damage anything. Too much will clog the catalytic converters so just be cautious.
 

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Discussion Starter #12
Got everything back together and she ran perfect last night. Still some slight hesitation on my commute to work this morning. I am going to try to get an OBD code to pop up so I can figure out what's wrong. I'm suspecting a bad injector, so I will be tearing into the car again in the coming months.
 

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Discussion Starter #14
I have the exact same issue, carbon cleaned and slight hesitation at about 2500 rpm. Hope you have luck as I can not find it.
I'm suspecting an injector. I need to get the car to throw a code to be sure. Did you have your injectors serviced?
 

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Discussion Starter #16
I didnt. I was going too but the injector people told me it wasnt a symptom of injectors so I didnt do it.
I'm buying a Ross Tech cable to see what's going on. I had my car go into limp mode yesterday but didn't throw an engine light code. There is definitely a connector that's on its way out on the electrical side of things. This exact same thing happened when I put the car back together without the throttle body plugged in.
 

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Just a word of advice to remove the manifold bolts in the correct sequence and to tighten them to the correct torques and to replace the gaskets.

ELSAWIN:



Tightening sequence for intake manifold

– Tighten bolts for intake manifold in the sequence -1 to 10-.

t Tighten initially to 8 Nm

t Subsequently tighten to 9 Nm and then tighten 90° further
 

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Discussion Starter #19
Just a word of advice to remove the manifold bolts in the correct sequence and to tighten them to the correct torques and to replace the gaskets.

ELSAWIN:



Tightening sequence for intake manifold

? Tighten bolts for intake manifold in the sequence -1 to 10-.

t Tighten initially to 8 Nm

t Subsequently tighten to 9 Nm and then tighten 90° further
Excellent info. I'll update the OP with this once I get onto my laptop.

do you have pictures of the intake flaps? did you replace any parts while you had the manifolds off? would you say this was a 5 hours job?
Sorry, I don't have any pictures of the flaps. They were just oily. Wiped them off and put back on the car. I only replaced the gaskets and injector seals for this job with the exception of the adapter that connects to the intake tube just before the manifold since I broke it. I need to go back in to replace the injectors though. I'm suspecting one is faulty.
I can't really comment on the time for this job. I took a week to do it but I had knee surgery while I was waiting for parts. I could definitely do the disassembly and reassembly in about 3 hours. Cleaning was a real time consumer, though.
 

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I have the exact same issue, carbon cleaned and slight hesitation at about 2500 rpm. Hope you have luck as I can not find it.
Slight hesitation around 2500-2750 rpm is not carbon build up issue, it's ECU software problem. Older softwares have had hesitation around 2500-2750 rpm (EU ...560 001-007, 560F 001,002,004, US ...560G 001-004, newer version (EU ...560 008, ...560F 005, US ...560G 005-009) has moved it to 2000 rpm.

(these are ECU examples for m.y.2008 CAUA engine with original magnesium intake manifold. Newer engines have plastic intake manifold and different ECU numbers)

This hesitation is done because swirl flaps open in these rpm.

I did make sw. change and on my car they open in 1240rpm, so no hesitation now.
It did take me 3 years and 77 sw. revisions during testing... :mallet:

Sad thing is, that Audi did last changes of ECU sw. for S5 m.y. 2008 EU cars in 2009, for US cars in 2013 (!!!).
 
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