2004 A8 That sure nose dived in a hurry.....
 

Had car in dealer shop in Ft. Collins, Colorado. Last I talked to shop manager was Friday afternoon, agreed to them removing transmission to inspect torque converter and flex plate. I'd understood they were going to start that day and by this morning, have transmission backed off and components inspected.

Well, just spoke with shop manager and a rod just went through the engine this morning. They had driven the car out of the shop Friday, drove it back in this morning to start working on it, and while idling, engine made a noise and quit.

So, repair for engine with used block would be approximately $7,000, with no guarantees that there still isn't a second problem they suspected. He said car was worth $3,000 now, would apply that towards a trade with them, think he might have said would alternatively write out check, not sure.

How about them apples?

What caused the failure? With the number of symptoms they had to diagnose with, I wonder if they missed something they shouldn't have? For an engine to implode like that, it's unusual without it having been improperly performed work. I'm really sorry to hear about your problems.

Hmmm....crap luck! That mysterious rattle sounds like it was probably down to a partially spun big end bearing that finally seized, throwing the rod.

Either way, it's a very unusual failure mode on the 4.2 which is near as damn it bullit proof.

Sorry to hear
 

Sorry to hear. Yes, a very unusual failure.

Hard to walk away, but this sounds like one of them. New/rebuilt motor cost (even absent other issues) could be applied to getting a newer one already on the road. Only exception case I've had a few times is where I know the whole rest of the car is well kept up. That is, it is well above the average similar used vehicle you buy with who knows what lurking issues to come, especially with spotty or oral only description of supposed service history from about the fourth owner. So if you have babied it, kept it up and know it has a lot of miles left in the balance of systems, maybe. But, w/ ten year old cars maybe sold several times over previously, more likely an exception than norm.

I think the first VW guy was right.....
 

Farmjazz,

Sorry to hear this, but I think the first diagnosis may have been correct, "diagnosed as timing belt slip due to tensioner failing" and "Code showed misfire. So, Volkswagen shop that diagnosed timing problem was wrong" and "cause mechanic there crawled under and got his hand on the timing belt, and it seemed loose to him",
The reason it felt loose to him is that the tensioner was must likely loose when he checked it, it sounds to me that the he was correct and it was out of time, which let the valve or valves tap one or more pistons causing the misfire, "code showed misfire", that noise they heard was most likely the damaged rod bearing from the piston being jammed into valves, "also detected a rattling/rubbing on the backside of the engine. Detected at startup, absent for 15-20 seconds, then noticeable again", that was must likely the rod bearing spinning, so sometimes getting oil, sometimes not, and I do have to say, a rod knock does not sound like a bad T/C, or flywheel, and a good mechanic should know that sound, and should not run the engine without checking the oil for metal, etc.

I myself have over rev'ed one of my race engines and floated a valve, the valve although bent did not come in contact with the piston again after first strikes, and the engine only had a very light misfire, BUT the rod bearing on that cylinder showed signs of being hammered....

To me, there are so many signs that lead me to feel this was, I would ask to have all eight cylinders bore scoped and video recorded to show all pistons and valves.

Johnny J J

ps. check these.

2004 Audi A8 4 2L Vin L Engine Motor 78K | eBay

http://www.ebay.com/itm/ENGINE-LONG-BLOCK-ASSEMBLY-4-2L-V8-Audi-A8-D3-2004-2005-2006-04-05-06-BFM-62-331-/271840446115?hash=item3f4af406a3&vxp=mtr2004 Audi A8 Quattro Base 4.2L in Complete Engines | eBay

Ask your wife if a big red light was on for the last 50 miles.

+1

I'd appreciate hearing more. Tomorrow I'm driving out to Casper from central SD to pick up wife, expected to call dealership tomorrow to see about getting salvage check, but if there is something for me to pursue, I'm sure game. Whole thing seems odd as can be to me.

"To me, there are so many signs that lead me to feel this was, I would ask to have all eight cylinders bore scoped and video recorded to show all pistons and valves."

Signs that lead you to feel this was.............timing belt slip? I assumed if timing had slipped, a code would show that. Is this correct, or can the timing belt slip and only show misfire? By asking for all cylinders be bore scoped and video recorded.......I don't know enough about this to read between the lines. I'm just guessing since I don't know, but would you be looking for other cylinders to show damage also, and that would evidence or suspect timing problem causing multiple cylinder damage?

Since I'll be taking off tomorrow, would be very grateful for comments and further thoughts soon. I'm in no hurry to wrap things up, especially if there is something further to explore with this failure. But, seems from some other comments this could just be exceptional misfortune.

Again, biggest question I have is about code when car got to dealership in Fort Collins. Will timing belt problem show up as code specific to timing belt problem, or can it simply show misfire and be timing failure?

Thank you for your help. Please help further if you have something to add or emphasize.

Definitely not. Specifically said warning light came on, she drove approximately 1-2 miles and exited interstate, pulled into parking area and turned off car. Tried starting, wouldn't start. Turned over but didn't fire.

Okay, first, what warning light came on, please be specific, oil pressure, temp, check engine, etc., ALSO did your wife hear any noise of any kind, chirping, anything ?
Johnny J J