Nemo Time

Remember Nemo? He's the 1997 Audi A4 (B5 body style) that T bought and wrestled with for a few years, replacing the clutch and brake master cylinders as well as the clutch slave cylinder and repairing so many other things. I also did a TON on this car (just what I posted on), so the fact that he needed more was a little, well... frustrating. When T moved to LA, he signed Nemo over to me, and then we thought we had sold it within the family, after replacing the driver-side rear axle and wheel bearing. Only to have the power steering fail... ending that transfer. So, Nemo has sat in my driveway. He has many little issues: a water leak into the driver's footwell, a broken front passenger window regulator, a big hole in the exhaust, a sunroof that won't open, some other little missing bits, and, of course, the failed power steering. Today's post covers my efforts to resolve enough of these items so he can be registered and driven again.

Before I begin, the sanding on Zed continues. I will post an update next week, hopefully, with some meaningful progress. In the meantime, I have slowly crawled along with Nemo over the last few weeks, so I thought an update was in order.

Water Leak

Schmidty sniffing the ECU box

I believe I solved the water leak when I discovered that the plastic box that holds the ECU was not entirely attached. There is an obvious nut on the outside, near the driver fender. There is a second nut inside the box closer to the engine, back near the fire wall. Underneath the ECU, is a large (like 1 inch by 3 inch) rectangle opening into the footwell. This hole has a gasket, but if the box is not held down firmly enough to engage the gasket, water which finds its way under the box (which is a for-sure here in rainy PacNW) will run straight into the driver footwell. In Nemo's case, the inner nut was simply not there. I found one, and snugged it down. Problem solved. I hope.

Accessing the Exhaust

big old rusty dirty cat

The big hole in the exhaust has been a major pain to solve. The aftermarket cat-back exhaust installed by a prior owner did not have any support between the end of the header and the rear axle. It did, however, have a section of flex-pipe immediately after the header, creating the car's lowest point. So, when the car drove over speed bumps or dramatic driveway transitions, it was the flex-pipe which hit the ground. Eventually, that flex-pipe failed. With the failure came a Check-Engine-Light (CEL) preventing a DEQ pass. To resolve, I removed the catalytic converter, downpipe and mid-pipe so I could replace the failed flex-pipe. This removal is challenged by the usual issues with exhaust hardware, but the Audi has additional things, like heat shields, in the way. So, the air box needs to come out, and the passenger front wheel comes off so you can access everything. Even then, Audi engineers seem to like to use different fastener types and sizes pretty much everywhere. Of course, the owner plays a role here too.

Cat Away

cat out

After trying a wide array of tools, I ultimately needed a hacksaw blade to cut through the rusted bolts between the catalytic converter and the down pipe. The PO had used regular steel fasteners to attach them, and even after multiple days of spraying Kroil on them, they were rusted tight. I cut the bolts, sending the hacksaw blade between the opposing flanges, at least far enough for the bolts to snap in half when I applied torque to one end with a socket-wrench. This took some time and patience, and because of how the bolts are oriented in the engine compartment, I was only able to sever 2 of them. This loosened the connection enough for the downpipe to rotate on that last bolt, allowing me to pull the 2 out the top of the engine as a unit. I cut the other bolt off, separating the 2 pieces, on the driveway. Holding the downpipe still with my boot, I cut the lip of the flex-pipe from it using my angle grinder.

Before I started, I ordered a brand-new catalytic converter, thinking that the one that was on there was 10+ years old, and of unknown working condition. After spending many hours cutting through rusty bolts with a hand-held hacksaw blade, I do NOT want to do this R&R again even if the fasteners are new. So, I'm grateful I made that purchase decision. After I got the cat on the ground I could see the Audi symbol on it, so either it was replaced at a dealer a long time ago or it was the original. Either way, at almost 300k miles, it is unlikely that catalytic converter was still doing its job well. Well enough to pass Oregon DEQ? We'll never know. Besides, the old bolts are rust-attached to that old thing, so re-install would have been considerably challenged.

new cheap hanger

On the other end of the hole in the exhaust, I removed the mid-pipe (2 bolts), cut off the remains of the flex-pipe with the death wheel and re-installed the mid-pipe. I added a support immediately behind where the flex-pipe-to-mid-pipe joint will appear so it is held up and away from the ground better. For the support, I got one of those cheap bolt-on hangers, attaching to the rear of the transmission through an unused bolt hole in the rear of the case.

Cat In

Moving back up front, I installed the new cat first, re-introducing the original O2 sensors as I went. To the cat, I added the down pipe and then finally connected the down pipe and mid-pipe with the flex pipe, fitting things together with clamps and exhaust dope. 

I got Nemo back on the ground to take him for a test spin around the usual neighborhood track. Before backing him off the ramps, I checked the exhaust for leaks, and it looked good, with a little puff of smoke coming out the tailpipe. The exhaust sounded much better, and it doesn't leak. So, around the block we went. It still hangs low, but it is fairly well tucked up under the body compared to before. The rear end ride height is so low, there is a near-constant threat of bottoming out. I will need to resolve that soon. He drove great; plenty of pull from the turbo, and the exhaust was much quieter than he had been on the last test drive. Clearly, the noise and smoke is going out the tail now. I thought I might have heard the rear passenger wheel bearing, though, so there may still be more adventure coming. And, yes, you can drive a car with failed power steering; you just need forearms like Popeye if you need to turn the wheels when the car is not in motion.... like to maneuver it out of a shop bay into the driveway through a 9 point turn. 

Oh Two

Oh Nemo.... O2

Unfortunately, the CEL is still on, with a code (P0134) indicating that the upstream (before cat) O2 sensor is bad. When I considered the smoke puff out the tailpipe when it was sitting on ramps, this makes sense: if the computer doesn't know the air-fuel mixture sent from the O2 sensor, it sends a richer fuel mixture to protect the engine from being too lean, which is why a failing O2 sensor is a DEQ auto-fail. So, I ordered a replacement upstream O2 sensor and now I'm waiting on shipping before I take another test. Since the error code did not include a code for the downstream O2 sensor, one might think that the old catalytic converter was still working. As I pondered this, I picked it up from one end, and I could hear dust settling through it. So, even if it wasn't toast, it was soon to be. When the new O2 sensor arrives, I'll slap it in, clear the code and go for a spin. If the CEL doesn't return, we may take him through DEQ before the next update. 

That's it for today. Like I mentioned at the top, the sanding on Zed continues. After sanding him smooth with the 320-grit, I did not like some of the orange-peel effect I found underneath, so I sanded the primer end-to-end with 320-grit again. Thanks, as always, for following along-