Last post on May 13, 2013 at 11:21 AM
You are in the Audi A6
What is this discussion about?
Audi A6, Sedan, Wagon
#1205 of 1402 Re: 1996 A6 Electrical Gremlins [chandler661]
Dec 05, 2009 (6:32 am)
Electrical Gremlins for sure:
The singular most difficult problem on any vehicle.
1. That Jekyl even has a voltage meter is highly unusual, but OK if you say so.
I'll get back to that in a moment.
1st I'm not familiar with a "Head Unit" is that a Cylinder Head device or something to do with your radio/stereo?
Variations in voltage output to the battery from the Alternator are normal dependent upon what's being used on the vehicle at any given time. Of course this is under the assumption that all other electrical equipment is functioning correctly.
The list of electrical options is long, but if you start turning them on you increase the amount of voltage used from the battery and in turn the amount of alternator out put to produce the electrical energy used.
By way of elimination based on what your telling me:
a. The battery is new (12 Volt, AMPS RATING ???????)
b. The radio/stereo is OK.
The first place to look is the Alternator. Why ! Because Alternators have built in voltage regulators and brushes.
The first test would be a voltage output under load test, Not just at idle. of the alternator.If it does not meet the rated output range for your model car with it's optional electrical equipment then it's one or more of three things.
a. The Voltage Regulator portion of the Alternator has gone south.
b. The Alternator contact brushes are worn and need to be replaced.
c. The Drive belt for the Alternator which also drives the water pump may be to loose or worn and needs replacing and adjusting.
d. Also take a look at the battery cables, Clean and tighten to the Plus & Minus poles. While your checking cables go back and find out what the Amp rating of your "New Battery" is, it maybe that you bought a battery which is not sufficient for your car. It should be a least the rating indicating in the Owners operation manual.
I Always start with the cheapest things first. The regulator portion of the alternator maybe part of the contact brush assembly.
NOW, Having said all of that the questions is ! Does that have anything to do with your " No Start/Engine dies problem" The short answer is MAYBE.
The motor not starting/dies is one or more of several areas:
I am going from the assumption that when your car does not start the starter motor turns the engine over.
a. Fuel, Air, Temperature, Electrical, Vacuum hoses, and Related sensors for any one of the above.
Having said that and based on your previous comments about "Head Unit" Power Booster of some kind, and that the car has 200,000 plus miles on it that the problem is alternator related.
In particular the High Voltage Coils on each spark plug have a particular voltage and amp rating requirement that they can cause the spark plugs to ignite the fuel.
If that voltage requirement is not meet the engine may not start or die if the battery
is not being charged to a particular capacity to keep everything running.
Note: Just an after thought but does your 96 A6 have a safety switch on the Gear Selector which precludes the car from starting when it's in a gear other than Park????
In any case a reliable Audi dealer or third party shop that has the correct diagnostic equipment for your car is the best choice.
I will stop here as I don't want to confuse the issue by talking about AIR, FUEL, Vacuum Hoses and related sensors.
Good Luck Chandlier661
#1206 of 1402 Re: 1996 A6 Electrical Gremlins [jkaudia6]
Dec 05, 2009 (9:19 am)
Hey JKAudiA6, Thanx for the quick response. I was hoping I didn't write too much. I'll cut too the chase and answer some questions.
First, just to clarify, "head unit" is another term for CD receiver because it controls everything for the stereo. The capacitor is used between the battery and the amplifier in the power chain. It's used to supply extra juice to the amp when the music needs an extra boost as not to drain the battery all the time. When you run high power (big watts), the lights will dim or blink. Using a capacitor will alleviate the problem as long as it's sufficient enough for the wattage, aka Farad size. 1 Farad per 1000 watts. I stated that because it's part of the electrical system now and is usually the first thing mechanics will question for electrical problems. I know how to wire a stereo, but factory wiring diagnostics can be confusing and daunting. I ruled that out because no matter how loud it plays, there is no draw on the meter. The meter shows a drop with or without the stereo connected.
I do believe the car has a shifter safety switch. My wife leaves it in drive all the time and I try to start it not realizing it's still in drive and nothing. So I think that answers your question.
The car calls for 600-650 amps and the first battery I installed was rated 700 amps and the 2nd is 750. I do believe they are both sufficient. I swapped them out after the one that came with the car just to rule it out.
I contemplated changing the alternator for a while, but decided not to for 2 reasons. 1, they are ridiculously expensive. 2, I figured that the car will draw power, naturally, when stuff is on. But I also figured that if the alt was bad, it wouldn't charge the system back once the car was back under power. Every time, the meter would go back up. If the alt was bad, it would continue to draw off the battery til it was out of juice, right?? I didn't want to just start replacing stuff until ti was fixed and I'm out a couple grand.
The dash has a series of gauges: tach, speedo, warning lights, fuel, coolant temp, clock, oil temp, and volt meter (last three above the center stack). The S6 has all the same, just a different color. I also have a volt meter on the capacitor for the stereo and for the amp. Both are digital and always read the same #s as each other and the analog meter on the dash.
The car has one serpentine belt for everything. I replaced that in the beginning of the summer. I also replaced the timing belt and tensioners.
Battery cables are ok. There's no corrosion, breakage, and they're bolted tight to the terminals. The thing is that it's done the same thing with three different batteries. I replaced the one that came with the car because it wouldn't take a charge anymore. I bought a new one and nothing changed. I then swapped it for the one in the S. Same thing. So I'm ruling out the battery.
Yesterday freaked me out and I actually thought the transmission was shot. Another question: what does the oil pressure waring light have to do with anything? Is there possibly a circuit that tripped that and stopped the engine??
Don't worry confusing me with anything. Actually talking about sensors might be appropriate hear seeing how sensors are electrical. Maybe the oil pressure sensor is faulty or something along that circuit.
I appreciate your time and trying to resolve my issue. Get back to me if you have anything else. I just don't want to spend 3 bills on an alternator and still have the same problem. Hope to hear from you soon.
#1207 of 1402 Re: 2000 Audi A6 Quattro [abniz]
Dec 06, 2009 (2:49 pm)
Hi abniz I had the same problem with my window. I had to replace the window motor to fix it. However, I have learned the trick of revving your engine to have the widow go up. Please let me know if this helps.
#1208 of 1402 Re: 1996 A6 Electrical Gremlins [chandler661]
Dec 07, 2009 (12:45 pm)
Well at least we can say with reasonable certainty what it is not.
I did not mention this before but I am not an Electrical Genie. If I take a cable from it's connector I can remember where it was and put it back.
As for the "Engine Oil Pressure light" and a related sensor, it could be wired in such a way that when the oil pressure goes below a certain level it would shut the motor down. I don't know if the S6 Audi has such a sensor/switch wired that way or not. Actually I don't think they would wire a switch in that way for a street car. Have you ever tried to steer a car with power steering when the engine suddenly dies (All but impossible). It may be located on or near the base of the Oil canister mounting bracket, Dip Stick or Oil Pan.
It sounds to me like your in to working on your own vehicle but at some point money will have to be spent. For that reason I would strongly recommend getting reliable info from Audi. For your problem there are several ways to go with this line of thought.
a. There is an Audi Web Page called "ERWIN.COM" for Audi USA. They have all the Documents, service INFO and Tool recommendation one needs to do self repair. The Hourly Flat rate as I recall is $21.00, you buy what you need, Manuals, diagrams, tools and research your problem in advance. How it all works is on the web page.
b. Or ! Get an Error Code read out from the on board computers *ECU's in your car from a dealer\service facility. I have know Idea what that cost.
c. The other option is go to the Vag COM web page state side and look in to buying
a diagnostic software package and interface cable for your car.
Note: Depending on your skill level this may or may not be for you.
Should you decide this last option be advised that it's very easy to render your vehicle inoperative (Make a mistake).
As for the problem:
a. I'd do one last test on that Gear shift lever when it's in the "PARK POSITION"
Wiggle it to see if you can recreate the problem.
b. The sensors control several different areas of the engine operation:
1. Air Flow(Volume), Ignition spark, timing, Air, water, coolant and Ambient temperatures. All of this data is sent to one or more "Electronic Control Units"
(ECU) which is really a small specialized computer. In it's memory banks (Chips) are tables of control parameters for each given area, Air, fuel, temperatures, Spark and ignition. The most simple of all these are most likely the thermal type sensors
Hot/Cold, sends an electrical implus to the ECU which interprets the data received
looks a tablle of data and sends a message back to the control devices which provide the Air, Fuel, Ignition etc.
Note: If this data is not being interpreted correctly then an error code is generated and stored in the ECU for Service personnel to interpret with VAGCOM software.
The other posiblitiy is a "COLD Soldier Joint" in a Sending unit or ECU which most often is effected either by
1. Vibration or HOT & COLD Operational Temperature or Ambient Temp's.
Back in the 70's I had a Porsche 914 which would stop running while driving on the Freeway in Los Angeles.
One last note which I found refreshed what knowledge I do have.
The Web Page is called: THE CAR BIBLE Google it the author is very knowledgeable about how cars work.
As I'm sure you understand Chandler661 and as we confirmed earlier Electrical Stuff is tough.
Best Regard & Be patient.
#1209 of 1402 Re: Akebono Ceramic Pads [allmet33]
Dec 07, 2009 (12:57 pm)
Thanks for the TIP on Ceramic Brake pads. I'd never really considered anything else.
Living in Germany, we have a whole different set of rules as it pertains to cars & Maintenance. But if they are approved OE perhaps I can use them here as well.
I'll dial in on the net and see.
#1210 of 1402 2003 Audi A6 blows cold air
Dec 07, 2009 (4:03 pm)
My 2003 Audi A6 blows cold air even when the engine is hot. The only way that I can get any warm air in the cabin is to set both thermostats to Hi, have the defrost on front window and have the heater in econ mode. Even then it only blows moderately warm air and not enough to heat the cabin. Any ideas on what is causing this?
#1211 of 1402 Re: Akebono Ceramic Pads [jkaudia6]
Dec 08, 2009 (12:33 pm)
No problem...I can tell you that I used them on my '96 Camry (never changed the rotors) and the car had about 140k miles before it was totaled. I used them on my '02 Sonata and put over 100k miles on the original rotors before having to replace them due to warpage (installed custom wheels with no torque wrench), but the thickness of the rotors was not an issue. Currently, I've been using them on my '06 Azera with almost 80k miles and the original rotors as well. With around 300k miles of experience with ceramic pads...I feel comfortable recommending them. If you're a hard driver...then I would suggest swapping out the regular rotors with cross drilled slotted rotors so that the heat will dissipate much faster and fear of warpage to to extreme heat becomes less of an issue.
#1212 of 1402 Re: 2003 Audi A6 blows cold air [qfixer]
Dec 08, 2009 (2:28 pm)
Heating problems, I had the same thing happen to me on my previous ride a BMW
520i 1990 with 200,000 + Kilometers.
I'm going to assume all of your heating vents are functional and you don't have any moisture under the dash on the floor area from a leaking Heater radiator or control value if it's under the dash.
a.The first thing to check is the water/coolant level in the cooling system. If you have coolant/antifreeze use that or buy some. (Be Careful, if the engine is Operating temp it's HOTHOT WATER, Wear Gloves and don't stand directly over the radiator when adding coolant/water.
b. There are two radiator hosed on your engine one for returning the water from the engine (at the Top of the radiator) after it's made it's way through the engine and heating system.
The other hose should be at the bottom which then feeds the cooled water back in to the engine to maintain the correct operating temperature for the engine.
What your look for are the following symptoms after the engine has been running long enough to reach what should be normal operating temp as indicated by the Water Temp gauge on the Instrument cluster.
a. First Make sure that there are no water leaks from any of the radiator or heating hoses, the engine (around the Cylinder head gasket area) or the radiator. This includes removing the Oil filler cap and the Dip Stick to see if it has a Milky brown film on either part which would indicate moisture in the engine.
Note: If you find Milky/coffee brown film on either of those, and the engine is running
turn it off, wait for it to cool down then remove and mark each spark plug according to the cylinder it came from. What your looking for is an abnormal coloration of the electrode (The Ceramic tip), Go to this Web Page on the Net and Read About Spark plugs and blown head gaskets. http://www/thecarbible.com
b. Make sure that the over flow system is in operational condition:ie, radiator cap gasket is not leaking & the pressure re-leaf value in the cap is functioning. Also that the overflow tank is sealed, and that the cooling system has sufficient water/coolant, fill to the mark on the tank. The coolant should be about 50% of the total volume of the coolant system capacity;ie, 5 gal.capacity should have 2.5 gals. of coolant.
Coolant or Antifreeze as it's most often referred to is the stabilizer of the water temperature in the engine. It keeps the water within a predetermined operational temp.range. Look to your Operational manual for the correct capacity.
c. The heater hoses which feed the heating system are most always smaller in size
having an outside diameter of about 1inch. They are connected to fittings on the firewall behind the engine and run from there to the engine block and to a "Heater Control Valve" which regulates the water flow based on heater control settings on the dash.Note: The heater control valve will either be Mechanical or Electromechanical depending on whether or not you have electrically control regulators for heating on the dash (The Knobs) heating/Air conditioning system. If there are electrical wires connected to the heater control value it's electro-mechanical.
d. Once you've determined the cooling system is sealed, no leaks anywhere, and there is sufficient water/coolant the next step is:
While the engine is running, press the Lower Radiator hose with your hand and note two things.(CAREFUL for the FAN Blades ROTATING)
1. Does the hose feel soft like it has little or no water in it ??????
2. Is it COOL to the touch?????????????????????
Note: If one or both of these conditions exist then I would say your Water Thermostat is not functioning correctly;ie, not opening or closing allowing the water to follow based on it's predetermined temp.range. This may also mean AIR in the System which prevents the Heater in the Car from reaching normal operation temp's.
Note: If your Thermostat is bad then have it replaced and if you have high mileage on your car and have never had the water pump replace, now is the time because it
most always near the Thermostat.
e. Finally ! If things improve after adding water but normal operational temps for the heating system are not totally reached then do this:
In rapid succession turn the HEAT control knob to FULL ON and OFF several times, if you the heater starts putting out more heat after this then your control knobs are partially controlling the heater control valve. There is most likely a Printed Circuit board (PCB) on the back side of the control knob area which sends electical impulses to the Hearter control valve and they are not working correctly.
This could be in addition to bad Thermostat and would require replacement or repair. Repair if you can find a Service which repairs PCB's, Look to the Net for
this type of service, your dealer will always just replace the part, they don't repair parts on cars anymore.
Well Gfixer,, I'm sorry this had to be so long but a simply question does not mean a simply answer as you can see.
I may have forgotten something and I'm sure after you've check all these things out
you may even have a second question
#1213 of 1402 Re: 1996 A6 Electrical Gremlins [jkaudia6]
Dec 09, 2009 (11:25 am)
I appreciate the help and the words of encouragement. Unfortunately it may be a few days before I can get under the hood 'cuz we just had a snowstorm and I can only work outside. I'll let you know how I make out when I can. In the mean time I'm gonna check out the online stuff you let me know about. I'm pretty patient, but this car is for my wife to drive and it seems that when the holidays come, the car decides to take a vacation. So time is usually of the essence, but I'm also annoyed 'cuz I put a bunch of $$ and time into this car and I think it's a great car and has plenty of life left in it. I plan to get the car up to snuff, but just wish it wouldn't go bad when we really need it and the cash flow is low. I'll keep you posted.
#1214 of 1402 Re: 1996 A6 Electrical Gremlins [chandler661]
Dec 09, 2009 (12:33 pm)
Ya your "Snow Storm hit the European news this morning on CNN, bad timing to say the least. No fun working on a car outside, been there, done that.
A tip for you during the repair time. WAECO accessorizes company has a slip over Electric seat heater that plugs in to the Cigarette lighter, has a two position switch and an overload circuit built-in. That would be a perfect gift for the wife while the heaters not working and the Snow is falling, cost about 30 Euro here, that's about twenty bucks. Don't forget the Big Red Ribbon. I put one in the Father-in Laws car about a month ago, not for him, for my Mother-in Law.
Nothing like a bit of pressure during the Holidays.
Hang tough, Chandler:
Best regards to you and the family.
Have a great Christmas.