B7 RS4 - Looking for DIY on downpipe removal

B6/7 S4/RS4
#1

I’ve searched a bunch of different ways and on different sites and have not been able to locate a DIY on removing the downpipes on a B7 RS4 - anyone know if one exists or have any advice? I’m planning on doing it this weekend and want to make sure I have the right tools & any replacement parts for the job.

my assumptions are that you need to get it up high on jack stands so you have room to get them out - but how hard are the bolts to get at - I read the S4 top bolt is a PITA… also should I expect to need to replace bolts or anything in the process? I’m planning to gut the pre-cats. I’ve read how they are different than the S4 precats - but I’m not sure what else to expect.

Thanks!

#2

RS4 downpipes are a lot easier than S4 downpipes

the S4 has a small exhaust manifold, and the downpipes reach all the way up to that and bolt on
the RS4 has tri-y headers which extend quite a ways off the engine, so the downpipes are about 6-12" shorter than S4 downpipes…and are MUCH easier to get at

With that said, if you live in a snow state/province, and they have never been removed before (not likely they have) you will probably have some pretty angry bolts and may snap a stud in the process. Be prepared to deal with that.

#3

What Saki said.

I would spray the nuts and studs with penetrating oil a few times before trying to get the downpipes off. That way the studs are less likely to break.

#4

I’m thinking it might be best just to get this kit before I attempt?

http://www.ecstuning.com/Audi-B7_RS4--V8/Exhaust/View_All/ES2580177/

http://c1552172.r72.cf0.rackcdn.com/458227_x600.jpg

#5

I think I might have a few pictures of what you would expect to see. Let me look and I’ll try to do something quick to help. And give you a idea on what it will take. The RS4 Dps are simple to do. But as the other guys said rust is going to create a big issue with the studs.

#6

I can’t find all my pictures so I just tossed something quick for you.

The first thing the guys are talking about is broken or studs that back out. This one broke and then I had to drill it out. I had to do one that was so bad I had to dill it out and then the drill made the hole bigger so I had to use a nut and bolt rather then a stud.

http://audirevolution.net/addons/albums/images/44482203.jpg

The Dp removal on the RS4 is pretty strght forward other then making sure to check for and spray the studs on the Dps.

Here is what it looks like under the car. This is the JHM 2.75 full exhaust. Stock obviously isn’t going to look this good but this helps show a much cleaner idea without the cats in the way.

http://jhmotorsports.com/products/pictures/exhaust/B7-RS4/JHM_RS4_2-75_V2_Exhaust-X-pipe_installed_undercar_horiz.jpg

Here is a quick look of what the RS4 dps look like off the car they are not very big at all

http://jhmotorsports.com/shop/catalog/images/JHM_B7_RS4_Piggies.jpg

If your not formilure with how the audi stock exhaust works its clamped together by a sleeve system. When you look at it under the car the sleeves look like this. You can see it here with the two big 14mm bolts sticking out

http://jhmotorsports.com/products/pictures/piggies/JHM_Piggie_Pipe_Install_Help.jpg

In the picture above it talks about getting the 02s unplugged. Most of the Audi cars the 02s are on the fire wall on the Rs4 the 02s are bolted on the passenger side of the transmission. It can be hard to see but this is a look up at them. Its hard to see you need to get the right angle.

http://audirevolution.net/addons/albums/images/307229384.jpg

Just to give you a refrence if your laying on the ground this is how close the bolts are on the driver side dp.

http://audirevolution.net/view-image/959/rs4-driver-dp

Really the entire thing is easy to do.

Jack the car up. Let me know if you don’t know the jacking points. There easy to spot of you don’t

try to have the car semi warm
jack the car up.
spray the dp studs before you do anything
Pull off the clamps. You might have to pull back on the catback to get the clamps off.
By this time the penetration spray should have taken effect. Take off the nuts on the Dps.
From here you can take out the 02 sensors. They are a 21mm or you can reach up on the side of the passenger side of the transmission and un hook the wires from the holder and then unplug each wire.

This should give you a good idea on what it will take and what your looking at.

#7

Excellent info: thanks for the details!

#8

Yes - let those studs soak! My car had one break as well.

#9

I jacked it up tonight and blasted it with “PB Blaster”. the bolts do look pretty crusty…

#10

Don’t be afraid to soak them a few times.

#11

well crap. I did soak them a few times - once last night and once again this morning.

the studs laughed at the PB blaster - chuckled at the torch and snapped as soon as I applied some torque… the bolts/studs are pretty much fused together.

so on the passenger side, I have the two lower nuts off - but only by snapping them off…

Problem at this point: the top bolt on the passenger side is inline with the O2 sensor. I’ve tried every wobble extension I have and still no love. I have a O2 removal kit - with lots of different socket options, but because of the way it sits right on top of the pipe I don’t have a way to use any of them.

when you guys did this - did you remove that O2 sensor first and then try and get to the top stud? or did you find a way to get at the bolt without removing it?

I didn’t want to start on the drivers side if I cant get the passenger side off…

oh, and I need smaller hands…

#12

Remove the 02. Its going to be much easier if you take the time and disconnect the wire from the harness. Other wise you just twist the wires and it can damage the 02.

I would remove the 02 and then get a long extension and get far enough back you can get a straight approach on it. If you get too far at an angle you can round the bolt and then your really up the water.

#13

If you can load some of the damaged pictures up to the site here. I think it will help others in the future understand how jobs like this can go.

#14

KEEP IN MIND…those front o2 sensors are wideband and will be about $250 each to replace if you wreck them. So be ginger.

The pre-twist is a good technique. i.e. gentlry twist the wires OPPOSITE of the the way you’re about to unthread or thread the sensor where it plugs in the bung…that way you’re giving some slack for the turning while you remove it.

unless you mean you’re going to disconnect at the trans…

#15

fun fun. Well, I’ve run out of time this weekend for the project and didn’t get to finish - I didn’t anticipate this much complication. :stuck_out_tongue:

passenger side bolts pre-soak - pretty rusty.

http://www.voidopolis.com/images/rs4/downpipe/Downpipe-bolts-1024.jpg

And after PB Blaster, hitting them with heat and more PB Blaster - both studs snapped.

http://www.voidopolis.com/images/rs4/downpipe/studs-snapped-1024.jpg

this is how the bolts look after 7 years of exhaust duty. It doesn’t look like the loosened up at all…

http://www.voidopolis.com/images/rs4/downpipe/bolts-1024.jpg

I wish the nut cutter I picked up would have fit up there, it would have been easier to just cut the nuts off and deal with the studs separately. Its such a small space to work in that it make almost every move difficult. I may try that on the drivers side and I will definitely do that on the clamp bolts - as there is enough room for that.

The Driver side bolts are very close to the top/primary cat and getting at them is more difficult than the passenger side. I did try a combination of wobble and hinge sockets to try and get a socket to even fit on the bolt… I also tried some different wrenches. there just isn’t much room to work and that is very frustrating.

I removed the O2 sensor from the passenger side downpipe. it is inline with the top most bolt. So that must be removed before you attempt to remove that bolt. this tool form Harbor Freight helped quite a bit - I used this in combination with a stubby ratchet and used another ratchet as a pry-bar and got it unstuck.

http://www.harborfreight.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/i/m/image_13142.jpg

from there, I could just remove it by hand (with help from the tool).

the nuts that hold the clamps on are pretty much rusted over as well. This is after the 2nd treatment with PB Blaster (the first time I let all the nuts sit overnight and then hit them again an hour before I started) and hitting them with the wire brush.

http://www.voidopolis.com/images/rs4/downpipe/exhaust-clamp-1024.jpg

I guess I shouldn’t have been so surprised - 7 years of the elements and the heat cycles that those nuts/studs see - I’m not surprised they snapped.

#16

That’s snow state rust no doubt about that. Where are you located?

#17

Cleveland, Ohio - I’ve only had the car for about a month - it was previously in southern Ohio (still snowy) and I believe in the New England area before that. So, yes, snow & possibly salt air.

#18

Rust, we really get hit hard up here.

A quick tip on getting the bolts, on the driver side. Get a long extension, about 2’ to 3’ if you get a pivot ball extension you can get back by the tail section of the transmission. When you’re that far back you can see and get to the bolts with less restriction and a better view.

#19

Great thread, very informative.
Planning another attempt at this myself in a couple of weeks.
Had a go last weekend, one nut released no problem, second sheared a stud, then I gave up :-[
Now have a set of new studs but might end up being a nut and bolt job once drilled out.

Been doing some research but this is the only thread I’ve come across covering this.
According to Elsawin there is a requirement to drop the gearbox mount and lower the box by up to 60mm.
Is this not necessary??

On the drivers, R/H side on mine there is already a bolt with a 10mm head in place of one of the studs with a load of thread protruding above.
Obviously been changed at some point.

Will get some pictures up when I get back to it, if I remember.

#20

so, I’ve got two broken studs so far… and I believe, knowing the condition of the two that snapped, that I’d probably break the others if I try and remove them. I have a shop estimating $900 or so to finish the whole job for me. That seems high. And, if they remove the pipes and break more studs, the cost will go higher.

how difficult is the extraction job or worse - drilling and tapping with the headers still on the car?