Downpipes - engine in car question

[Jim Haseltine]

OK. With the subframe and driveshafts off I've managed to get 5 of the downpipe nuts off and I think I'll be able to get the inner nut off the right side today. What I can't get to are the upper nuts. So, do I need to lower the back of the engine (or the entire thing), if so, by how much and what do I need to disconnect so I don't break things?
Or do I just give up and go through the entire engine out procedure again? I suspect it's going to be the second as the O2 sensors in the rear cats are solid and the loom have a considerable number of unreachable tie wraps.

[IanH755]

As it's the first time you're trying this I'd be heavily tempted to drop the engine again as much of a pain as that is going to be.

I know MRC drop the subframe to drop the engine a little but by now they have the experience to know exactly what to loosen and how much you can safely drop, whereas if you get it wrong it's going to be a lot more costly in the long run for you.

[welwynnick]

I used to have an ex-police Vauxhall Senator 3.0 24V (wonderful car). I changed the engine mounts, and lifted the engine slightly to do so. Engines were simpler in those days, and I was very careful to avoid damaging anything, but I still strained an oil cooler pipe, which promptly started leaking. Since then I've been very cautious about raising or lowering the engine.

On the other hand, you've already taken the engine out once, which time will probably show as being the biggest, baddest job on any car, so you can probably answer that question better than anyone. Engines are always allowed to move an inch or so in most directions. Gearbox mountings in particular are often very soft, and will normally allow a lot of movement, so if it's a matter of tilting, you probably have quite a bit of latitude.

Is this so you can take your turbo out?

Nick

[Jim Haseltine]

As it's the first time you're trying this I'd be heavily tempted to drop the engine again as much of a pain as that is going to be.

I don't like things beating me but after 3 hours on my back failing to shift any other nuts this morning I've just decided to do that. It doesn't help that the heat shield over the RH turbo allows no room to move.
Two/three reasons - I want to check the back of the RH turbo as the amount of smoke from the car is phenomenal - it could be months of condensation or it could be over fueling (but no misfire so I doubt that) but there's that noise too. I disconnected the oil return from the rh turbo yesterday, it doesn't look like it's been running dry. The neither of the flexy joints are in good condition, the left has breaks in the braid and the right has a lot of carbon on the outside. While I'm about it, I replaced the inner cv on the RH driveshaft nearly 3 years ago and I was never happy with the gaiter Audi supplied in the kit - it's far longer than that on the left driveshaft and it looks quite compressed in service so I'm going to change it while I'm at it.
At least I've a pretty good idea what I have to do to pull the engine and if I do need to deal with the turbo I'll be a fair way through the job.

[Jim Haseltine]

it could be months of condensation

Judging from the mayonnaise in the thick pipe from the PCV separator and the oil tank that's probably a lot of it. Because of the current situation since christmas all I've done with the car is run it up to normal temperature a couple of times and before that it stood unused for quite a considerable period so I wouldn't be surprised.
I'm stripping as little as possible from the engine then I'll drain the fluids and pull the engine forwards enough to get to the last downpipe nuts. With luck once the rh pipe is off it might give me just enough room to reach the O2 connectors on the box.

[Jim Haseltine]

Fiddled around taking stuff off the top of the engine last Saturday then got delayed by a covid vaccination which made me feel really bad on Sunday and major family problems this week so today was the first real chance I had to do anything. I'd been leaving it as long as possible but the sensible thing is to disconnect the battery isn't it, so that was my first job. Unlocked the car, opened the driver's door and the fuel pump primed - never really noticed that before - this time I couldn't ignore it, as I couldn't ignore the jet of fuel that sprayed out under the car, it seems that whilst I'd been under the bonnet last week I'd unknowingly managed to disconnect the quick-release connector in the fuel line.
So, oil is out, coolant is out, gear selector cable is disconnected, everything is stripped back to a point where tomorrow I should be able to get to the last coolant hoses then drop the engine on Monday - all weather permitting of course.

[welwynnick]

Which are the nuts that are difficult to get off?

On the face of it, that sounds like a fairly depressing prospect, Jim. But since you're one of a select bunch of individuals who are doing it more than once, do you think your experience is helping you because you know what to do, or does it make it worse because you do know what lies ahead?

Nick

[Jim Haseltine]

The two top nuts and the one on the engine side of the RH pipe. Having done the job about 18 months back it's not as daunting second time around - I'm doing things slightly differently as I know the things that were really awkward last time. For instance, this time I'm leaving all the pipes attached to the radiator and just removing them from the engine. There's the added benefit that not only do I know how to get to things, but rather than having to deal with fastenings that have been in place for many years they're coming undone fairly easily - the only problem I've had so far was one of the bolts holding the left intercooler and additional radiator together. I suppose that with lockdowns and having retired since the last time I did it I've the benefit of being able to take my time rather than being pushed to get thing completed during my annual leave. I'd rather the weather was a bit warmer though.

[Jim Haseltine]

Couldn't complain about the weather today as it was warm enough in the sun to work in short sleeves. I've now reached the point I should have been at this time last week with the engine and box now attached by just 14 bolts - the 6 for the engine mounts and the 8 on the transmission carrier. I had to remove the top hose at the radiator because the clip at the other end of it was impossible to reach with the tools I have. I'm pretty certain that all the hoses except the fuel line and the PS rack supply are disconnected but I'll be taking care when I move the power unit tomorrow - I very nearly missed the PS pump feed but caught that in my last check.

[Jim Haseltine]

5 hours. Engine dropped - slowly, good thing too as I completely forgot about the PS rack supply hose that I mentioned in my last post. Anyway, dropped the engine & box by about 6" and pulled the unit forward by about the same amount. Got the last downpipe nuts off then set about disconnecting the O2 sensors - that was easy, what wasn't was dealing with the plethora of tie wraps. The flexy in the LH downpipe appears to be ok but the other is shot, I suspect that it's only the braid that's keeping it together.
So: Do I replace just one and do I go for weld-on or clamp-on replacements? I'm thinking that clamp on would make things simpler if I was to delete the cats at some point.

[Doug_RS6]

What about V-bands? Nice neat solution. That would be my choice if I was to have an exhaust made.