Audi 100/A6 (C4 92-97) FAQ Digest
11-23-2006, 06:30 PM
#121
Fix for broken light switches above doors
<center><img src="http://pictureposter.audiworld.com/57225/map_light_fix_1.jpg"></center><p>Both of my front door map lights had broken slider switches. Unfortunately, only one slider switch was found in the car.
I repaired the broken back of the switch by drilling a 1/16" hole at an angle and then screwing in a #4 x 3/8" long phillips head screw.
I was careful not to run the drill bit through the front side of the switch and I only threaded in the screw (at an angle) far enough to make the light switch functional again.
Note: As you screw in the screw, the metal contact piece wants to climb the threads and distort. This will lift it's contact feet off the contacts of the switch housing. So, once you have the screw installed, push the middle of the metal contact so it sort of climbs back down the screw threads and gets back into a normal working position.
A second note: After writing this, it was brough to my attention by AW list member "Evol(Jonathon)" that you can install the map lights above the rear doors, into the positions over the front doors. This gives you the additional bonus of having lights that come on over both front seats when you open the front doors. The light switches are already wired for this feature, so this nice little mod is 'plug-n-play'.
I repaired the broken back of the switch by drilling a 1/16" hole at an angle and then screwing in a #4 x 3/8" long phillips head screw.
I was careful not to run the drill bit through the front side of the switch and I only threaded in the screw (at an angle) far enough to make the light switch functional again.
Note: As you screw in the screw, the metal contact piece wants to climb the threads and distort. This will lift it's contact feet off the contacts of the switch housing. So, once you have the screw installed, push the middle of the metal contact so it sort of climbs back down the screw threads and gets back into a normal working position.
A second note: After writing this, it was brough to my attention by AW list member "Evol(Jonathon)" that you can install the map lights above the rear doors, into the positions over the front doors. This gives you the additional bonus of having lights that come on over both front seats when you open the front doors. The light switches are already wired for this feature, so this nice little mod is 'plug-n-play'.
11-30-2006, 09:02 PM
#122
How to replace your power steering pump
Very simple, less than 30min to do the job, no special tools.
1) Remove the top and front plastic engine covers
2) Remove serpentine belt
3) Wrap serp belt around power steering pump pulley from the driver's side, and hold tight with your fist, like a strap wrench. Now undo the 3 allen head bolts and remove the pulley.
4) Remove the 3 vertical allen head bolts that hold the coil pack to the top of the power steering pump.
5) Pull the spark plug wires off of the coil pack.
6) Lift coil pack up and lay over to the passenger side out of the way.
7) I pulled the vacuum ball off completely. This broke the cloth covered 3mm vacuum hose that goes from the ball to the green hard plastic vac line, but I had new stuff, so no big deal.
8) Stuff rags or paper towels around the back and driver's side of the power steering pump
9) Loosen the 22mm top pipe fitting. Move pipe rearward a bit and snug up fitting with your fingers.
10) You can now get to the 2 vertical 13mm bolts at each rear corner of the pump. I have a 13mm wobbly socket, which was perfect for this location.
11) Remove the hose going to the driver's side of the pump and wad up some paper towel to stuff in the end. Stand the hose up so it doesn't leak onto the engine.
12) Remove the 2 horizontal allen head bolts on each side of the front of the pump. They're sort of back low behind where the pulley covers.
13) Remove the 22mm banjo bolt and both aluminum crush washers from the pipe on the top of the pump.
14) Lift the pump up and out.
I reused the aluminum crush washers on the 22mm banjo bolt. No need to over tighten this fitting, just snug is all you need.
I set the pump in and got all 4 mounting bolts started, before I fully tightened any of them. I also left that 22mm banjo bolt loose and didn't fully tighten it until the pump was fully bolted in place. But, I got the banjo bolt started while the pump was still sitting loose. This helps get the banjo bolt started with just your fingers and keeps you from wrecking the threads!
To tighten the 3 allen bolts on the power steering pulley, I wrap the serp belt back around it, but this time I hold it in my fist from the passenger side....and tighten the 3 bolts.
Once you get it all back together, leave the plastic engine covers off. So you can check for leaks.
Top up the power steering reservior with 11S Pentosin.
Start the car and turn the wheel lock to lock slowly and top up the fluid as needed. Continue turning the steering lock to lock until no more groaning or gurgling is heard. I actually rev the engine to about 2 grand and do this. Bleeds the pump fast and gets you back on the road.
Go for a test drive....I went up to a parking lot and did a bunch of parking manuevers to see if it was really fixed.
Check for leaks.
If there are no leaks, top up the fluid if needed and put your engine covers back on.
1) Remove the top and front plastic engine covers
2) Remove serpentine belt
3) Wrap serp belt around power steering pump pulley from the driver's side, and hold tight with your fist, like a strap wrench. Now undo the 3 allen head bolts and remove the pulley.
4) Remove the 3 vertical allen head bolts that hold the coil pack to the top of the power steering pump.
5) Pull the spark plug wires off of the coil pack.
6) Lift coil pack up and lay over to the passenger side out of the way.
7) I pulled the vacuum ball off completely. This broke the cloth covered 3mm vacuum hose that goes from the ball to the green hard plastic vac line, but I had new stuff, so no big deal.
8) Stuff rags or paper towels around the back and driver's side of the power steering pump
9) Loosen the 22mm top pipe fitting. Move pipe rearward a bit and snug up fitting with your fingers.
10) You can now get to the 2 vertical 13mm bolts at each rear corner of the pump. I have a 13mm wobbly socket, which was perfect for this location.
11) Remove the hose going to the driver's side of the pump and wad up some paper towel to stuff in the end. Stand the hose up so it doesn't leak onto the engine.
12) Remove the 2 horizontal allen head bolts on each side of the front of the pump. They're sort of back low behind where the pulley covers.
13) Remove the 22mm banjo bolt and both aluminum crush washers from the pipe on the top of the pump.
14) Lift the pump up and out.
I reused the aluminum crush washers on the 22mm banjo bolt. No need to over tighten this fitting, just snug is all you need.
I set the pump in and got all 4 mounting bolts started, before I fully tightened any of them. I also left that 22mm banjo bolt loose and didn't fully tighten it until the pump was fully bolted in place. But, I got the banjo bolt started while the pump was still sitting loose. This helps get the banjo bolt started with just your fingers and keeps you from wrecking the threads!
To tighten the 3 allen bolts on the power steering pulley, I wrap the serp belt back around it, but this time I hold it in my fist from the passenger side....and tighten the 3 bolts.
Once you get it all back together, leave the plastic engine covers off. So you can check for leaks.
Top up the power steering reservior with 11S Pentosin.
Start the car and turn the wheel lock to lock slowly and top up the fluid as needed. Continue turning the steering lock to lock until no more groaning or gurgling is heard. I actually rev the engine to about 2 grand and do this. Bleeds the pump fast and gets you back on the road.
Go for a test drive....I went up to a parking lot and did a bunch of parking manuevers to see if it was really fixed.
Check for leaks.
If there are no leaks, top up the fluid if needed and put your engine covers back on.
12-03-2006, 06:48 PM
#123
Cure for front suspension noise
There have been quite a number of posts from owners who are experiencing some sort of noise from the front suspension. Either clunking, popping, clanking, or other such sounds. While there are numerous causes for these, from lower control arm bushings, to upper strut mounts....and the list goes on, I thought I would detail what it took to solve the noises from the front end of my '95 A6 Avant Quattro with 175,000mi on it when we purchased it in June '06......
Quick review as this has been ongoing since buying the car and I finally decided to just let it get so bad that it was easily duplicated.
This adventure started with clunk/thud type noise in the floor that could be felt in me feet when I just started to accelerate or just before coming to a stop.
Recentering the front snubber mount helped, replacing front motor mounts improved it, replacing the rear transmission mounts cured it...or so I thought.
About a month later, we started getting a popping sound during take off, and then right before stopping....*pop-pop-pop* Sort of a binding type of sound.
Replacing the new front KYB GR-2's with Boge Turbo Gas didn't help and the top strut bushings were already new.
One thing I noticed was that the noise wasn't present at all when the car was cold, but after driving for 10-15min would commence and get worse the longer you drove. At it's worse it was popping even while turning the tires left or right, or going in and out of driveways.
Okay....so fast foreward to the repair. After a number of errands on a hot day and it's about 75*F out, the noise was just crazy. So bad infact, that I could finally just sit in the driveway and turn the steering lock to lock. It would pop like crazy.
Got my wife to start turning it lock to lock while I listened, watched, and grabbed every part of the steering, suspension and subframe to feel where the popping was occuring.
Weirdest thing I've ever seen. The noise was transmitting through every piece of suspension to the point that it almost seemed like steering rack.
Ultimately, I pulled the belly pan and watched the front right swaybar mount popping and moving due to loose bolts.
Just tightened up the foreward most bolt with a 1/2" air impact gun and the noise is now gone...at least in the driveway. The rear bolt is really loose and spinning with the gun, so I've got to come up with a way to grab the top of the bolt.
So, with the stiff power steering fixed and now this, I'm a happy Avant owner again....
.....just back from a test drive and it's all quiet.
Quick review as this has been ongoing since buying the car and I finally decided to just let it get so bad that it was easily duplicated.
This adventure started with clunk/thud type noise in the floor that could be felt in me feet when I just started to accelerate or just before coming to a stop.
Recentering the front snubber mount helped, replacing front motor mounts improved it, replacing the rear transmission mounts cured it...or so I thought.
About a month later, we started getting a popping sound during take off, and then right before stopping....*pop-pop-pop* Sort of a binding type of sound.
Replacing the new front KYB GR-2's with Boge Turbo Gas didn't help and the top strut bushings were already new.
One thing I noticed was that the noise wasn't present at all when the car was cold, but after driving for 10-15min would commence and get worse the longer you drove. At it's worse it was popping even while turning the tires left or right, or going in and out of driveways.
Okay....so fast foreward to the repair. After a number of errands on a hot day and it's about 75*F out, the noise was just crazy. So bad infact, that I could finally just sit in the driveway and turn the steering lock to lock. It would pop like crazy.
Got my wife to start turning it lock to lock while I listened, watched, and grabbed every part of the steering, suspension and subframe to feel where the popping was occuring.
Weirdest thing I've ever seen. The noise was transmitting through every piece of suspension to the point that it almost seemed like steering rack.
Ultimately, I pulled the belly pan and watched the front right swaybar mount popping and moving due to loose bolts.
Just tightened up the foreward most bolt with a 1/2" air impact gun and the noise is now gone...at least in the driveway. The rear bolt is really loose and spinning with the gun, so I've got to come up with a way to grab the top of the bolt.
So, with the stiff power steering fixed and now this, I'm a happy Avant owner again....
.....just back from a test drive and it's all quiet.
12-28-2006, 07:38 AM
#125
AudiWorld Senior Member
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Phatnoise Adapter for C4
Audi C4 A6 CD Changer Harness Pinouts
I've been researching the pinouts for my 1997 A6 Sedan so I can install a Phatnoise box. The Phatnoise does not support the stock Delta CC radio so I bought a Concert I head unit on eBay and replaced the Delta. See my Concert I install in the <a href="https://forums.audiworld.com/a6100/msgs/31818.phtml">100/A6 FAQ.</a>
Not wanting to rip the car apart to replace the changer harness, I decided to make an adapter that will allow me to plug a standard Phatnoise 13-pin Audi cable into the factory C4 8-pin harness. <a href="https://forums.audiworld.com/a6100/msgs/57727.phtml">MAA6 did it differently, cut off the connectors and soldered the Phatnoise adapter cable directly to the harness in the trunk</a>. I didn't want to cut the harness but that's just me.
Here's what I have discovered from many places but primarily Audiworld Forums. The C4 A6 CD changer harness pinouts are not documented anywhere that I could find so I did a continuity check from the head unit end of my harness to the 8-pin DIN connector in the trunk.
<img src="http://pictureposter.audiworld.com/56914/c4_harness_pinout.jpg" />
The radio connector is as seen facing the rear of the radio. The C4 A6 8-pin female connector and the 99 A4 13-pin male are shown above facing the end of the open connector. Pins 13, 14, 15 on the Concert I have different functions than the Delta CC. The rest of the pins are the same. The C4 CD changer won't work with the Concert I.
Notice that the 8-pin connector has no pin for the Data Ground. The shielding on the DI and CLOCK lines is grounded to the head unit but that ground won't be carried across the 8-pin connector to the Phatnoise chassis. It doesn't seem to be an issue even though I didn't ground the Phatnoise box to the car chassis.
Making the Adapter
To make the adapter, I cut off the 13-pin connector and 18" of the CDC harness from a 99 A4 in a salvage yard. Then soldered an 8-pin connector to the cut end. The 8-pin DIN connector is available from <a href="http://www.mpja.com/listitems.asp?dept=95&main=83&type=1">www.mpja.com </a> and, if you can't find a donor car, the 13-pin connector from <a href="http://www.cablesandconnectors.com/26500-26.HTM">www.cablesandconnectors.com</a>.
Here's the exposed end of the 99 A4 CDC harness.
<img src="http://pictureposter.audiworld.com/56914/adapter_wires.jpg" />
The wires need to be connected to the 8-pin male connector this way. The colors of the A4 harness wires are given.
<img src="http://pictureposter.audiworld.com/56914/adapter_connections.jpg" />
This is the tedious part. Getting all the wires cut to the same length, positioned, soldered and covered. Takes decent soldering skills.
<img src="http://pictureposter.audiworld.com/56914/soldered_to_8-pin.jpg" />
And here's the finished adapter. On the left is the 8-pin DIN male connector that connects to the C4 harness. On the right is the 13-pin DIN male connector that connects to the Phatnoise cable.
<img src="http://pictureposter.audiworld.com/56914/finished_adapter.jpg" />
In my sedan, the CD changer harness is located in the trunk behind the right side trim material. It was zip-tied to the gas filler bracket. In my Avant, the harness is on the left side inside the storage compartment.
I plugged my adapter into the C4 CDC harness and plugged the Phatnoise cable into the other end.
Now for the smoke test. Ignition on, radio on, press Mode, wait a few seconds, bingo...voice from the Phatnoise comes over the speakers. I didn't have to configure for my Concert radio head. Apparently, the previous owner had already configured the Phatbox for the right radio.
I've been enjoying the music for a few weeks now. The quality of sound is excellent. My method of grounding works just fine, i.e. no static. I figured out how to set general random mode so songs are selected across everything on the hard disk. Over 1600 tracks and counting.
Only a year since I started this project and I'm still working on it (5/30/2008). Just 2 more tasks:
(1) Fabricate a permanent mounting bracket for the sedan trunk
(2) Install a German voice in the Phatnoise.
More to come...
I've been researching the pinouts for my 1997 A6 Sedan so I can install a Phatnoise box. The Phatnoise does not support the stock Delta CC radio so I bought a Concert I head unit on eBay and replaced the Delta. See my Concert I install in the <a href="https://forums.audiworld.com/a6100/msgs/31818.phtml">100/A6 FAQ.</a>
Not wanting to rip the car apart to replace the changer harness, I decided to make an adapter that will allow me to plug a standard Phatnoise 13-pin Audi cable into the factory C4 8-pin harness. <a href="https://forums.audiworld.com/a6100/msgs/57727.phtml">MAA6 did it differently, cut off the connectors and soldered the Phatnoise adapter cable directly to the harness in the trunk</a>. I didn't want to cut the harness but that's just me.
Here's what I have discovered from many places but primarily Audiworld Forums. The C4 A6 CD changer harness pinouts are not documented anywhere that I could find so I did a continuity check from the head unit end of my harness to the 8-pin DIN connector in the trunk.
<img src="http://pictureposter.audiworld.com/56914/c4_harness_pinout.jpg" />
The radio connector is as seen facing the rear of the radio. The C4 A6 8-pin female connector and the 99 A4 13-pin male are shown above facing the end of the open connector. Pins 13, 14, 15 on the Concert I have different functions than the Delta CC. The rest of the pins are the same. The C4 CD changer won't work with the Concert I.
Notice that the 8-pin connector has no pin for the Data Ground. The shielding on the DI and CLOCK lines is grounded to the head unit but that ground won't be carried across the 8-pin connector to the Phatnoise chassis. It doesn't seem to be an issue even though I didn't ground the Phatnoise box to the car chassis.
Making the Adapter
To make the adapter, I cut off the 13-pin connector and 18" of the CDC harness from a 99 A4 in a salvage yard. Then soldered an 8-pin connector to the cut end. The 8-pin DIN connector is available from <a href="http://www.mpja.com/listitems.asp?dept=95&main=83&type=1">www.mpja.com </a> and, if you can't find a donor car, the 13-pin connector from <a href="http://www.cablesandconnectors.com/26500-26.HTM">www.cablesandconnectors.com</a>.
Here's the exposed end of the 99 A4 CDC harness.
<img src="http://pictureposter.audiworld.com/56914/adapter_wires.jpg" />
The wires need to be connected to the 8-pin male connector this way. The colors of the A4 harness wires are given.
<img src="http://pictureposter.audiworld.com/56914/adapter_connections.jpg" />
This is the tedious part. Getting all the wires cut to the same length, positioned, soldered and covered. Takes decent soldering skills.
<img src="http://pictureposter.audiworld.com/56914/soldered_to_8-pin.jpg" />
And here's the finished adapter. On the left is the 8-pin DIN male connector that connects to the C4 harness. On the right is the 13-pin DIN male connector that connects to the Phatnoise cable.
<img src="http://pictureposter.audiworld.com/56914/finished_adapter.jpg" />
In my sedan, the CD changer harness is located in the trunk behind the right side trim material. It was zip-tied to the gas filler bracket. In my Avant, the harness is on the left side inside the storage compartment.
I plugged my adapter into the C4 CDC harness and plugged the Phatnoise cable into the other end.
Now for the smoke test. Ignition on, radio on, press Mode, wait a few seconds, bingo...voice from the Phatnoise comes over the speakers. I didn't have to configure for my Concert radio head. Apparently, the previous owner had already configured the Phatbox for the right radio.
I've been enjoying the music for a few weeks now. The quality of sound is excellent. My method of grounding works just fine, i.e. no static. I figured out how to set general random mode so songs are selected across everything on the hard disk. Over 1600 tracks and counting.
Only a year since I started this project and I'm still working on it (5/30/2008). Just 2 more tasks:
(1) Fabricate a permanent mounting bracket for the sedan trunk
(2) Install a German voice in the Phatnoise.
More to come...
01-19-2007, 06:47 AM
#128
Power Steering System Flush & Filter Cleaning
Over time the power steering fluid, "11S Pentosin" full synthetic, gets dirty and the power steering filter in the reservior bottle gets packed full of crud.
The result is usually stiff steering during parking, and groaning from the power steering pump, especially first thing in the morning.
The link below from the Audipages.com forum is a nicely detailed and photographed set of instructions for flushing the power steering system and cleaning the power steering filter.
That filter runs about $69, so take care of it!<ul><li><a href="http://www.audipages.com/Tech_Articles/susp_whls_brake_steer/psflush.html">http://www.audipages.com/Tech_Articles/susp_whls_brake_steer/psflush.html</a</li></ul>
The result is usually stiff steering during parking, and groaning from the power steering pump, especially first thing in the morning.
The link below from the Audipages.com forum is a nicely detailed and photographed set of instructions for flushing the power steering system and cleaning the power steering filter.
That filter runs about $69, so take care of it!<ul><li><a href="http://www.audipages.com/Tech_Articles/susp_whls_brake_steer/psflush.html">http://www.audipages.com/Tech_Articles/susp_whls_brake_steer/psflush.html</a</li></ul>
01-21-2007, 09:23 AM
#129
Transmission Wiring Harness Failure Technical Bulletin
These bulletins are thanks to Viv "fair cape" in South Africa who was kind enough to scan and post them recently.
<img src="http://pictureposter.audiworld.com/87187/clip0077.jpg">
<img src="http://pictureposter.audiworld.com/87187/clip0078.jpg">
<img src="http://pictureposter.audiworld.com/87187/clip0079.jpg">
<img src="http://pictureposter.audiworld.com/87187/clip0080.jpg">
<img src="http://pictureposter.audiworld.com/87187/clip0077.jpg">
<img src="http://pictureposter.audiworld.com/87187/clip0078.jpg">
<img src="http://pictureposter.audiworld.com/87187/clip0079.jpg">
<img src="http://pictureposter.audiworld.com/87187/clip0080.jpg">
