Pre-cat removal

[fukinavit]

Hi all, I know a few of you guys on here have done this. I had planned on tackling this at the weekend, however I have found some time to make a start today.
I looked over some other posts and thought I had a good idea. I have the car up high on axle stands and so far have done the following:
Loosened the front two subframe bolts (don't think this really did anything)
removed the rear two subframe bolts (with a jack under the trans to take the weight)
Removed drive shaft heatshield
I looked at V8weights post on this and I know he removed the control arms and disconnected the drive shaft but I was told this was not all necessary.
Anyway, right now the rear subframe has dropped about 2 inches max, and still theres not enough room to get to the top downpipe bolts. it seems the subframe doesn't want to drop any more, as there was little weight on the rear jack.
Any ideas or is this as far as it goes and I have to just suck it up and figure a way to get at the bolts?

[Bigglezworth]

Based upon what you have just outlined above, you have guaranteed just torn apart your rubber snubber mount located just above the alternator.... You need to put the front clip in to the service position in order to remove the snubber (or in your case replace it now that you've broken it by putting the entire weight of the engine c/w cradle on it). Well, you might be able to get to the nut from below while still leaving the snubber fastened to the chassis/bracket on top. I've never tried this as I always put the clip in to service position and remove the snubber. In order to get to the bolts on the top, it's best to remove the Y-pipe as it blocks access to things. The Y-pipe can also hang things up on the front as it can only shift so far with the upper intercooler hoses still attached.

You can access the DP's with the lower control arms still attached, but in order to ensure you don't over torsen the upper control arms I recommend you look to remove them from the upright. Depending on how tiny your hands are, tools used, etc., it's highly likely you will also need to disconnect the struts from the lower control arms in order to ensure the cradle can drop enough. You also need to disconnect the radiator hoses leaving the firewall and feeding the recirc pipe and temperature sensor located on the back of the heads. Finally, be careful on all your cooling lines on the drivers side as they don't all have sufficient slack to do what you are trying, and also be careful on dropping the rear more than the front so that you don't impact with anything on the front clip (which should be okay as long as you are in service position).

You can leave the drive shaft hooked up and all drive axles hooked up, but as you drop more on the rear, you need to ensure the heat shields are removed and also best if you unbolt the center support bearing bracket.

Then, and only then, hope that your bolts aren't rusted on and remove nicely without destroying your studs or snapping off....

[fukinavit]

thanks for the info, on all the posts I have read about doing this no one mentions anything about the snubber mount, but good to know. from what I can see it looks okay as there has been little to no movement at the front, like I said its only dropped a little at the back. the jack still has some weight but I can tell its not loaded fully.
I think like you say its being held back by the control arms.
ill loosen the upper mounting plate and let the struts come down a little.
I was just going by a thread which basically said "just loosen the four subframe bolts and tilt the back down enough to get at the dps", think it was Doug whom I believe has a shop or something. Anyway, ill plug away and see what else I can damage!

[lswing]

Nice of you to help Bigglez...nothing is as easy as it seems or people say. Just wait until you get to clearing the cats!

[Bigglezworth]

Just wait until you get to clearing the cats!Gutting the pre-cats is no small feat. Conservatively takes 1 hour per pipe. An air hammer with a long chisel greatly assists. Otherwise a host of arm work.

[fukinavit]

That's why I asked here as guys like bigglez have been there and done it so all input is greatly welcomed. so true when people say"yeah did the whole engine swap and rebuild in a day" most of the time its bullshit. ive done precats before on my 2.7t, so I now all about those. they were tight but the RS makes that look easy.

[Bigglezworth]

so true when people say"yeah did the whole engine swap and rebuild in a day" most of the time its bullshit.Yep. There's no easy way to remove the powerplant from this chassis. There are some minor efficiencies and as with anything, you do it enough times you become quicker and wiser. There's a very good reason why book time is billed out a almost $4K for just the R&R - without doing any actual maintenance or repair...

[kruat]

So do gutted cats flow as well or close to what aftermarket dps do? Is it worth the money for aftermarket dps?

[Bigglezworth]

Have never used after market so can't comment. See posts #95 & 97 on other thread.


http://www.rs6.com/showthread.php/25915-10SECS4-Tune-anyone-tried-it/page6

[fukinavit]

So do gutted cats flow as well or close to what aftermarket dps do? Is it worth the money for aftermarket dps?

from what ive heard, the standard RS6 dps once gutted flow really well due to their size, very close to true free flow dps.

On my other 27tt A6, I gutted the dps first with original exhaust system, it was a big improvement and greater spool up noise. then I bought a turbo back magnaflow (with 2.5in dowpipes) exhaust system and then noticed another gain, although this was mainly down to the full exhaust I believe.
in my opinion the cost of aftermarket downpipes is not worth the coin compared to gutting the originals.

[ttboost]

Sorry, just saw this...I seem to recall removing the front wheels and inner fender wells gets you in there too, at least for a bolt or two. Have fun gutting. Half way through the job, you will be second guessing the return on your "investment". It will be worth it, but you will be thinking...

[ttboost]

Yep. There's no easy way to remove the powerplant from this chassis. There are some minor efficiencies and as with anything, you do it enough times you become quicker and wiser. There's a very good reason why book time is billed out a almost $4K for just the R&R - without doing any actual maintenance or repair...

Yep. Some guys drop it out the bottom, some come out the front, after removing the front clip. A lot of things CAN be done with the engine in the car, but ultimately, it's almost always easier to just pull the engine anyway. If you have a lift and can swing a wrench, engine and trans comes out the bottom in 5-6hrs hours with no help. Easily 5 with another set of hands and eyes...

[s8prtotype]

Downpipes are being made for under $400 as you're doing this, might be wise to wait on them to finish and save your stockers for later.

[ttboost]

Downpipes are being made for under $400 as you're doing this, might be wise to wait on them to finish and save your stockers for later.

Yep...I had a spare set...needed my stockers for emissions here...with the manual, it was only a hour or so job to swap them...

[lswing]

Great time for ceramic heat shield coating too. I did mine, just feels better knowing some of that heat is kept off the trans.

You say pre-cats...I assume you're doing all cats and scrapping emissions? Just the little uppers would help I guess. Upper pre, lower main right.

[fukinavit]

Great time for ceramic heat shield coating too. I did mine, just feels better knowing some of that heat is kept off the trans.

You say pre-cats...I assume you're doing all cats and scrapping emissions? Just the little uppers would help I guess. Upper pre, lower main right.

Yes, just the pre-cats, going to leave the mains for now. The uppers make a big improvement.

im thinking of holding the engine from the top with my engine hoist as the rear jack kinda gets in the way. nice thing is I can pick away at it as like most its not my DD, got the 2.7 for that. tons of snow here now anyway so its not going anywhere soon.

ill probably just wrap them, ceramic and aftermarket is nice but this way its free, kinda.

[ttboost]

Hmmm, not sure I would wrap a header I couldn't see and inspect once in a while. Header wrap collects oil, and whatever else leaks...fire hazard...sometimes free isn't good...ceramic coating is the best...reflects heat back in, where it belongs...better spool too...

[Bigglezworth]

http://gecarchitecture.send6.com/b19c2de4/
Files:

<tbody>


Filename

Size



1

ENGINE REMOVING.pdf

1.00MB



2

ENGINE INSTALLING.pdf

225.48KB



3

ENGINE AND TRANSMISSION SEPARATING.pdf

409.58KB


</tbody>

[fukinavit]

Sorry, just saw this...I seem to recall removing the front wheels and inner fender wells gets you in there too, at least for a bolt or two. Have fun gutting. Half way through the job, you will be second guessing the return on your "investment". It will be worth it, but you will be thinking...

looked at this some more tonight, I don't think removing the fender wells does anything for access to the dps. in fact I can lower the rear of the engine probably 2.5in max before theres tension on the heater hoses going into the bulk head. The front of the engine doesn't move due to it resting on the mounts so loosening the front subframe bolts achieves nothing either, you have to remove the engine mounting brackets to actually lower the front.
ultimately lots of small details left out in peoples experience of removing these with the engine in place. realistically I can maybe get to 3 of the bolts on each downpipe and hope the come nice, but the top one just no way with that amount of drop. ive heard you can achieve 6 inches but I don't see how. I know my engine has never been out before, so all clips and hoses are original, so maybe this makes things tighter?, also guys with a 6 speed conv would have a way easier time due to the increased access form the trans side.
I have on order the bufkin pipe and also noticed the valve covers are leaking so this has made my decision to pull the engine much easier. may aswell as fighting this way just seems pointless.
im not saying it cant be done as obviously guys have done it, just on this occasion its not the best route for me.

thanks Bigglezworth for the links, very useful.

[ttboost]

Yeah, I've had my engine out 2 or 3 times now, and it's been a few years since I've had mine, so memory escapes me. Not sure if you saw this, but you can 100% remove the cross member under the transmission, with the engine in the car, which allows you considerably more access on each side. Just support the rear of the engine (under the transmission) with a floor jack, or post jack, and remove the "U" shaped cross member (1 big bolt on each side in the front and the 3 bolts/bracket in the back). You will have to leave the jack there, but it will be easier to reach up in there.

[Bigglezworth]

As I posted, you need to be able to drop the cradle enough to get your hands up in there. Once you drop it 4-6", you will be in the zone. You will also then be able to see the nuts that Mike references being visible from the sides behind the wheel well cover, AND you can also gain access to the top pair from above between the head and firewall. There is no question that you need to have the chassis in service position, remove the front stubber, remove the rad hose and heater hoses, and also remove the Y-pipe and upper and lower intercooler hoses. If you don't do this, you're going to reach maximum stretch on parts that aren't designed to support an engine. The entire cross member can be removed to get more access as Mike indicates, which necessitates bracing rear of transmission, and hanging engine from crane at front (just like shown on the engine removval and installation docs I posted a link to). I do believe that you don't need to go this extra step, but it's subject to how much you're struggling with tools, access, and coorperative fasteners....

If you're going to change the oil cooler coupler with a nice aluminum milled piece, along with valve covers, etc., then just bite the bullet and remove the front clip, disconnect all coolers, drive shafts, etc., and drop the hulk. Great time to clean things up also. You're welcome to PM me to discuss further as I've done this a trio of times also.

[Bigglezworth]

Further to confirm that you can in fact do this work with all electronics still hooked up to the engine, AND all cooler hoses full of fluids except for the upper rad hose, heater core hoses, and aux rad hose that takes off from lower rad hose pipe. Of course front clip is in service position, lower intercooler hoses removed, Y-pipe removed, and engine snubber removed. Also, headlight sensor removed, the coolant recirc pump unmounted from the drivers side frame, and the starter/alternator harness zip ties snipped to ensure sufficient slack. I've attached photos showing a dropped engine with the suspension still mounted and the cradle still in place. Driveshaft still mounted also, with only the exhaust decoupled, heat shield removed, and shifter cable unbolted (but still hooked up to PRNDL unit). I have an engine hoist so I use that to make mince meat of the weight while lowering/raising the hulk. Can be done with a pair of floor jacks and blocking given enough patience.

1601816019160151601616017160201602116022

[lswing]

Bigglez, is this your 20th or 50th time "pulling" the engine? You've got it down that's for sure, nice work!

[Bigglezworth]

Bigglez, is this your 20th or 50th time "pulling" the engine?I've only officially pulled the entire hulk twice. Once one my gray car to perform a tranny swap, and once on my blue car to swap turbos. All other work has been performed by dropping the cradle as needed as shown above which was only done to address EGT's, O2's, and a leaking banjo fitting at one of the turbo's coolant lines. Not good financial planning to own more than one of these cars if you can't wrench yourself....

[fukinavit]

so after being on shift for the past 2 weeks I am back at it again.
Engine is out, downpipes are gutted. next on the list is the oil cooler pipe, sai delete, valve cover and tensioner reseal and finally timing belt.
16093
awaiting their fate
.16090
before
16091
these tools made this an easy affair
16094
restriction be gone
16092
after

[Bigglezworth]

Yep. Have a few of those exact photos here. I kept the internals and am still looking to drop them off at the metal recycling place here. Worth some $$.

[Dmb408]

Question for this thread. Pre cat removal requires no coding or early failure of parts right? The primary 02's will still hold up the same amount of time, will the main cat fail quicker and start dropping cat efficiency codes?

[RSoverAll]

Question for this thread. Pre cat removal requires no coding or early failure of parts right? The primary 02's will still hold up the same amount of time, will the main cat fail quicker and start dropping cat efficiency codes?

The small cats are only in place to get the main catalysts to operating temp quicker. I don't believe removing it could cause the main cats to degrade any quicker or present a P0420 catalyst code.

I am pretty sure if the main cats do not get to temp quick enough to start turning the CO into CO2 in a certain amount of time the ECU sees this through the post O2 and could possibly set a code.

Don't quote me on that though...

As I wanna do this pre cat removal myself I am searching for answers as well.

[Bigglezworth]

I've driven with gutted precats on a pair of RS's here for the past couple of years. All temperatures of weather. All sensors OEM spec and in OEM locations. Have never thrown any code(s).

[RKturbo]

Finally got mine done today. A tip I found very helpful was to use a extra long masonry bit and drilled like 10 holes through it before I started chipping away at it with big screwdriver and hammer. Tried an air chisel and various long bits on the first one which really seemed to just make it harder and easily took a couple of hrs and then some to get done. The 2nd one I used the pre-drilling holes technique and it was done in 45 min tops. Now time to start putting everything back together tomorrow. :)