Hey everyone, had an issue with my 2014 a6 z51 the other day and am curious if anyone has experienced anything similar. I stopped at a light after driving 40 mins with no issue and the engine stalled out. All the other electronics (dash, radio, doors, etc) stayed on and didn’t flicker or anything but rpm’s dropped to 0. Tried to start it back up but it just cranked slow as if it had a dead battery. Also noticed a bit of white smoke coming from the passenger side of the hood. When I was able to push it out of the road to get a better look, we tried to jump start it and the cranking speed stayed the same and the battery showed 13v. However when we went to try a second or third time to crank it there was the same white smoke coming up from near the starter area that smelled like burning plastic/ electrical. Towed it home and was thinking maybe the starter shorted but not sure, but I noticed the ground wire next to the starter looked like it was starting to melt and the heat wrap was starting to come loose. Managed to get a a pic of those wires looks like it’s two grounds that go to the block. Does anyone know what could have caused this? And also was trying to see if there was a part number for that part of the harness/ if anyone knows where those grounds lead to. Any information helps, thank you.

Glue melting from top of wire insulation and dripping down the heat wrap

 

Have you done or changed anything to the car the last few weeks?

 

Either the bolt is loose or corroded, or the crimp of the wire into the eyelet terminal is internally corroded.

 

Starters can overamp / overheat when there is internal engine damage making the engine hard to turn.

Does the starter have 12 volts at the terminal? Is the 350 amp fuse on top of the battery positive blown?

Obviously fix the ground wires / connections too.

GL

Ron

 

I did change the alternator about 2 1/2 months ago, I’ll have to check back tomorrow when I can get it on a lift and test voltage at that ground. Also to the other replies, I can see the starter overheating if there’s too much resistance cranking but would that have made it die at the light like that? It also has been taking the same amount of time to crank normally before all this and never sounded sluggish or harsh.

 

There are other threads where an engine stalled and would not restart. The root cause turned out to be a broken valve spring, bearing, or other internal issue that caused the engine to lock up. My point is that the failed starter may be a symptom of the real problem.

Time for some heavy duty troubleshooting.

Ron

 

 

Was the torque tube ever replaced or taken out of car for any reason .....

Dave

 

Yes, the torque tube was replaced last August

 

Why the question about torque tube work? If the torque tube is not properly installed on an A6/A8 C7 there could be thrust bearing damage.

See this Chevy procedure:

Torque tube replacement

There are also many threads...

Ron

 

So still doing more diag, but after towing it in to the shop, the starter was the cause of the smell and smoke so that was replaced, which popped the 350 amp fuse to the main power wire. It didn’t pop on start up, instead it drove about 100 feet before popping while driving. They ended up putting a new 350 amp fuse in the place of the one on the fuse block and it started up fine, but then was fluctuating during idle as if if was relearning or something which we originally thought it was what that was. However when we went to pull it out and drive the lot to see if it would steady the idle, it blew again in the same way after about 100 feet. After swapping another fuse in, we noticed a tapping that’s very concerning coming from the back of the engine seemingly around where the torque tube attaches. I’ll attach a video of the sound, you can hear it loudest from under the car right behind the front wheel. Time for some serious digging now, but not too hopeful on the outcome.

 

Will definitely look into this as well, thought i was far enough out from the torque tube replacement to have any issues like that but the article does say it typically happens 3,000-5,000 miles after replacement, and it has been about 5-6k miles since it was done.

 

What was fluctuating ???...if a 350 amp fuse blows you need to trace some wires...you have a direct short to ground especially if it blows during driving...where are you in Florida ??

 

Agreed... check for a short circuit as its amont impossible to blow that 350 amp fuse , also if they did not install the torque tube following the proper installation procedure for setting end play your thrust bearing could be gone which could be why it starts and then stalls .... .. its only a matter of time before it locks up

Dave

 

It was the rpms fluctuating, it was as if it was struggling to idle. It would stay steady for a second or two then rpm’s would drop as if it were trying to stall, then jump back up. Sounded like someone was reving it slightly right before it would drop to a point where it would stall, but it seemed almost random there wasn’t like a consistent pattern to it. We have traced most of the main power wires and everything coming off of the starter and alternator and nothing looks like it’s shorting, especially not bad enough to blow the 350 amp fuse. The odd part is the timing of when it blows, the last two times have been about the same 50-100 feet from pulling out of the bay into the parking lot, even after letting it idle for 20-30 mins total the second time. Also I’m in the Tampa area.

 

That what I was thinking, tomorrow we are getting it back in the air and checking to see if it has any play or if it’s jammed up in there. I’m just curious as to how it would relate to the starter burning up and fuse blowing, feels like too much of a coincidence for it to happen at the same exact time. I’d get if the starter blew while trying to start, like if there was resistance from the thrust bearing putting too much load on the starter, but I don’t see the correlation since it’s dying while driving with the starter disengaged.

 

Agreed ... but once again it takes a direct short or a crazy electrical draw to pop that 350 amp fuse, you no doubt have a one of the above. I would disconnect the positive cable , then ground one side of your ohm meter , then touch the remaining probe agaist the positive clamp ... if zero ohms , move up to the rear fuse box, then front fuse box .... rinse and repeat

But before you do all of that work , You also need to perform a visual inspection, especially at the starter selonoid connections, you must drop the starter ..but why you ask 🙂 ???

Well , my money is on the positive connection at the starter selonoid is your problem . The positive connection has to be angled just right on the selonoid or ... it will short agaist the heat shield... or it will short to the block if not precisely angled when tightened....

When pushing the starter up to get the bolts started ... you can not see if the cable is rubbing the block or the shield.... I am willing to bet if you look at that end of the positive starter cable you will find that it was rubbing .

Ask me how I know ....😁 I drove my car for about 20 miles after replacing my starter because of a slow start condition.. I jumped in it to take a short trip to the supermarket. As I was leaving I made a left hand turn out of parking lot and bam everything shut off leaving me stuck in the middle of the road .... a tow home, and I found my 350 amp blown .. but since I just replaced the starter ... I checked those connections first and what a surprise, there was a tiny bit of clearance between the postive and the block but I guess vibration caused a tiny worn spot in the insulation, I guess when I turned left the engine torque was enough to make the wire rub till it finally shorted

Now I have replaced starters in a lot of cars and boats in my time ... and never had something like this bite me in the A$$...

Good luck with finding your short ....👍
Dave

 

Also you dont need to buy a new complete fuse and plastic holder that mounts on the top of the battery, a 350 amp fuse of the same type is avaliable on Amazon and its easy to mount...

 

I’ll definitely investigate this further, power went out at work today so can’t get it on a lift until that’s figured out. The only thing I’m still concerned about is that noise

 

Yes that’s what we’ve been doing, luckily I saw that on another thread before replacing the entire fuse block, we snapped off the original and have been using the generic Amazon 350 fuses, only blew one of those so far and have 3 left to do diag and testing with before putting the new $80 part on.