PVT_Rod_Fitzwell

Hi everyone, I am new to the forums here and I am looking for a bit of help. I bought a 2003 Audi A4 Quattro 1.8T in July of 2014 for $3900. It is a dark blue with black interior. Within a few weeks, I had already changed out the crankshaft speed sensor, oil level sensor, headlight washer pump... (the guy who owned it previously thought there was a hole in the washer tank.) So he used that lousy crap that has a cylinder of activator with a putty on the outside, ( you knead them together and press it onto something and it will harden) and without looking at what was leaking, just mashed it around the base of the washer fluid reservoir. The headlight washer pump was old and had rusted, causing the pump to seize and the plastic outer shell to split open, as oxidation causes metal to expand. Had he removed the tire and wheel well plastic, which takes all of 10 minutes, he would have been easily able to pull the pump and plug the hole or replace it. The reason I took time to explain that is because it's really a metaphor for every single thing that guy did to this car. The night I bought it I found that the rear passenger window was braced up because after I took the door apart, I found out that the green plastic piece that the cable snaps into was broken. I fixed that too. So in November, a ball joint on the driver's side tie rod end broke. I found a garage with good reviews that specialize in German and other European cars. I had them replace both tie rod assemblies, fix my exhaust leak, and I noticed some coolant under my car so I had them fix that. $1700 total. Coolant still leaked the next day. They replaced the lower radiator hose and some flange on the rear of the engine. I had taken the car back in. After an entire week, they had the audacity to insult my intelligence by telling me that all of the coolant puddled up and they didn't do a good job wiping it up so they basically had my car for a whole damn week and all that they did was take 2 minutes to wipe up coolant with a rag?!? A few days later, it was back in the shop. Eventually I got an endoscope with a 6ft bendable arm that has 4 led lights and can take up to 720p video or 3mp pictures. The lighting is adjustable, and the arm is gasoline, water, dirt, and grease proof. I knew that the leak was on the front driver side of the engine and only leaked when the car was off for 4-5hrs minimum. Eventually I found that the o-ring on the J plug was bad. I took the proof with me and that is now fixed. I also had all control arms, shocks, struts, tie rods, rear pads and rotors...nearly every part of my suspension is new...costing $4000. For those keeping track, yes, that's at least $5700 in parts and labor on a car that cost me $3900(all parts are genuine Audi OEM.). Today, while I was on the freeway, a fast paced knocking noise caught my attention. It sounds like it's coming from the rear driver side wheel. It's not engine rpm dependant, it gets faster when I am going faster and slower when I am going slow. When I accelerate or hit the brakes, the knocking noise disappears. Only when maintaining speed or letting off of the gas pedal does it make noise, but it is a loud and irritating sound. Any ideas on what is causing this noise? Thanks in advance and for anyone who took the time to read this, I appreciate it.

Kris Hansen

1. Check the lugs. 2. Check for loose tie rod, sway bar, shock, etc mounts..

John535is

I would be checking the tire, just make sure it's not separating on the inside edge and then the CV joints as well.

You can check this yourself. Lift the rear end and put non-compressible stands under the rear of the car. Secure the front wheels on flat ground so the car won't roll away. Spin the wheel slowly and check for a clicking sound on the rear shafts. With the car in the air and the suspension at it's lowest point the cv's are under the most angled stress. The joints will make a small ticking noise, but it should be constant and even. Sometimes laying under the car you can feel rather than hear the bad joint by letting the shaft spin in your hand. (hmm- I don't believe I just wrote that!). Check the rubber boots for grease coming out. If there is a significant click on one section of the rotation or if the boot is split, grease comes out and dirt gets in. The shaft should be able to move in and out about 20mm (3/4 inch) which allows the movement as the suspension goes up and down. The outer is more susceptible to damage than the inner as the wheel moves up and down at greater angles.
Next is the wheel bearing. Less likely but based on the poor history, it's possible the previous owner hit something hard. Bearings and differentials are more a whine noise than a click that will change pitch with speed though. If the bearing had collapsed, it will click for a very short time, right before it seizes! You will know its seized because it lets the smoke out.

If its the CV, your options are to replace the CV's and boots or replacement axle (which comes with new CV's and boots ready to install. My research indicates GKN is the original CV supplier which are much cheaper than dealer supplied for the same parts.

PVT_Rod_Fitzwell

Thanks for the fast, detailed, and informative responses. I'm one of those people who loves to learn as much about as many things as I can. The cause of the noise in this case was that the "mechanic" tried to kill me by not tightening any of the lug nuts on my rear driver's side wheel after they did all of that work. I realize that people are not infallible, and in spite of the best of efforts, mistakes happen. I double check, then check one more time after driving 50-75 miles, insuring myself that when I remove a wheel, its lug nuts get checked at least twice. To let a car leave without double checking the torque on the lug nuts is really inexcusable. Nevermind the car, but there are human lives that are depending upon the mechanic to make sure that the vehicle is safe to drive. If I had lost a wheel Monday morning, the roads were icy and slippery. I could have been killed or seriously injured, possibly even disabled. I think that if something like that were to happen that the mechanic and the garage would be sued and they will likely lose, possibly resulting in the business becoming unsustainable and closing. Anyway, I appreciate the info. The Audi is engineered substantially different from the other vehicles I have owned previously. This is my first turbocharged, intercooled, all wheel drive car with a tiptronic 5-speed auto trans. My last car was a 2000 Buick Regal GS with a Supercharged 3800 Series II L67 engine (3.8L V6) and HD 4-speed trans. It was comfortable and very quick. (I built a custom fender well intake, opened up the throttle body a bit, removed restricted parts of the exhaust system and replaced it with straight pipe, installed MSD coils, had the PCM custom tuned by one of the best 3800 tuners in the country, and other things here and there. ) Like most American cars, it was great in a straight line and was lousy in the corners. I say "most" because the 98 Ford Escort ZX2 I had was incredible on curvy roads. Tons of fun to drive. Of course I know that the suspension was designed by Lotus, so great handling is a given. Overall, the A4 stands above every other car I have owned.