1999 A6 Avant Back From the Dead - Update
 

Today was a big day. Back in November, I bought a 1999 A6 Avant Quattro for $800, but both the engine and the transmission were dead. This was understandable, since they were original, and the car had 368K miles on it. I couldn't pass up the deal because I already had a spare engine and transmission sitting in my barn that I had purchased as spares for my daughter's A6 last summer. I had never done an engine/transmission swap on an Audi before, and it turned out to be just as big of a hassle as I had imagined, but I got it started today. For some reason, the starter would not engage with the key, but I wired up a push-button starter switch, and it started right up. Ordinarily, I'm not sure that would be an appropriate modification for an Audi, but with this many miles on the car, I think it will meet the good-enough threshold, and I'll find somewhere on the dashboard to mount it.

I did discover, after installing the new engine, that the upper oil pan has a crack in it, so I'll have to drop the whole front subframe down to swap it for the one on the dead engine, but then it should be back on the road. Ease of service is apparently not on the list of things that the Germans pay attention to when they design their cars, so there were a few moments during this project when I thought the car would never move again under its own power, but now that it's running again, I would say it was worth the trouble. The body and the interior are in great shape, so it should have a couple hundred thousand more miles in it. Not bad for a total investment of $1,400, but time will have to tell.

As a side note, when I took the old engine apart to perform the autopsy, I discovered that the driver side cam chain tensioner assembly appears to have exploded, because the oil pan pickup was clogged with pieces of it, and there were bits of shrapnel scattered throughout the engine. There's no way that one will live to fight another day.

Subframe Removal
 

It turned out to be a simple matter of removing the four lower control arms, supporting the car, the engine, and the transmission somewhere other than the subframe, removing the engine and transmission mount bolts, unbolting the four subframe mounts, and dropping the subframe down. As you can see in the pictures below, with the subframe out of the way, you can see the entire upper oil pan. There are quite a few bolts that are covered by the lower oil pan, and two oil pickup tubes have to be removed. You can see the oil pump and the oil pump drive extending down into the lower pan. Fortunately, the upper pan can be removed without disturbing the oil pump once all of the bolts going into the engine block and the transmission bell housing have been removed. I also found something that looks like a rear engine block water jacket drain that I didn't know was there. At this point, I just need to remove the oil cooler and the front engine mount and I can drop the upper pan down.

The best part is that if I would have just checked the upper pan more closely before I installed the new engine, I could have avoided all of this. Next time I'll take a closer look.

Upper Oil Pan
 

The front motor mount, the oil cooler, the dipstick, the air box, and the starter all had to come back off to free the upper oil pan, but it came off. As you can see in the pictures, it's a complicated piece. You can also see the crack in the corner of the old one, which explains the chronic leak. The crank looked okay, and the oil pickup screen wasn't full of metal chunks like the old engine, so that's a good sign. Now I just have to put the subframe back in and put everything else back together and I can drive it out of the barn. I'm about three months behind schedule, but I think the list is finally starting to get shorter.

nice job, congrats on the resurrection!

Thanks! Like most of my projects, this one ended up being a bit more involved than I thought.

I reinstalled the lower oil pan last night and put the oil back in it and there weren't any drips tonight, so I put the front subframe back in. I had to order a lower control arm, but I can finish wiring the starter switch while I wait for that to arrive. It's really getting close now, and once I finish filling the transmission, it's coming down off the jack stands for the real test. And that's good because I've been neglecting my Mustang all winter while I was putting the wagon back together, and I have some catching up to do.

1999 A6 Avant Back from the Dead - Update
 

I installed the starter push button switch, and although it gives the car a bit of a JC Whitney look, it works great! I started it up and it was clattering a little, but that wasn't too surprising since I have no idea how many years it's been since this engine was last run. I let it idle while I filled the transmission and it slowly started to quiet down. When the transmission temperature reached 43 degrees C, the fluid started dripping out, which was great, since I didn't have any more to put in it. I shut it down, put the wheels back on, and took it down off the jack stands, and after I grab something for lunch, I'm going to see if I can actually drive it out of the barn under its own power. After a few months of work, I'm hoping for the best!