Light Smoke in Engine Bay

A6 All/ S6 All
#1

[Continuation of topic: “C6 S6 Misfire”. See topic for contextual and potentially relevant information associated with the below]

It turns out that the smoke and smell coming from the driver side engine bay was a leak in the oil pan, according to Audi. At high velocity, some of the oil would come in contact with a component that generally operates at a high temperature, causing it to vaporize and smoke to emerge. At least, they’re fixing that now, and it seemed to make sense to them.

I have yet to pick up the car, so I’ll find out on the BRAKE indicator light pretty soon. I haven’t had a misfire in quite some time, so after I get the car back, I’ll have to get up to my usual antics and see if the issue resurfaces. I generally keep the gas tank at least half full (seem to have fewer issues when I do), but I’ve ran it lower recently to put Techron in and haven’t had any of the issues with rough starts or anything that I’d had before, but I’m not convinced the problem is solved completely yet.

Will definitely keep you guys posted, thanks for your time so far.

Was playing around with an SRT8 on the highway, and I swear I could smell the smell that was associated when the car would produce that smoke I talked about earlier. I could be crazy, but I also notice that my car pulls to the right slightly when breaking. The smoke could potentially be coming from the brake on the left side, but I can’t tell for sure. The other day, just that rotor was covered in rust–it looked like water had dripped all over it, and where the water contacted the rotor, it rusted. I looked a day later and the rust was gone.

[Update]

I’ve noticed the car having a bit of a rough idle, and I think it’s pretty much always had that issue. It may be related to the ZF Lurch, I’m not sure, but the issue in that topic is definitely what I’m experiencing as well. Someone had mentioned the potentiality of bushings or control arms in the front causing an issue with alignment and tire wear, I wonder if that could be that? If the bushings need to be replaced, would that make the car idle rougher possibly? Also, the car definitely has a rougher start as my gas tank gets lower, as well as in very cold weather (well, this was true last winter, can’t tell if this is still true yet) and sometimes on certain inclines. I’m guessing fuel pump, filter, or both? Not sure.

Also, couple of things that I think might be connected I guess, but have no idea:

  1. when turning the car sharply, the car rumbles depending on how sharp of a turn you’re making. I’ve been told (at least, this is how I undestood it) that this is just an AWD issue caused by all the wheels not being able to turn fast enough at certain angles but are still rotating, so the ratio of the car’s velocity and the steering angle is too high and cannot be accounted for by traction control or any other feature. Could this be false and could something be rubbing on the driver side that is causing smoke at high speeds and high steering angles at high speed?
  2. I haven’t had to do it in several months, but reversing (either up or down, I can’t remember, sorry) a hill would cause a metal-to-metal sound that seemed to be produced by steering at certain angles. Control arms maybe?
  3. Sometimes, on heavy acceleration, the car seems to stop accelerating at a fixed RPM (usually 6000) at random times. I’ve primarily noticed it in 2nd gear after accelerating to around the redline in first and then approaching it in 2nd from either a stop or a slow rolling start.

The other day, the EPC light came on for a while. I believe I was below half a tank of gas, but I didn’t catch what triggered it. I don’t remember doing anything too crazy on the RPM-scale but could be wrong. If I did mess around, the car would have been about 75% on the way to operating temperature. The engine does seem a little rough when it’s not at operating temperature, but I’m guessing that’s normal for an engine this size (the biggest I’ve ever really experienced, so I don’t know for sure due to lack of reference)

No misfires for quite some time now.

#2

Lots of stuff to cover

The oil from an oil pan leak makes sense. The crank case is under pressure when you accelerate that will push oil past seals on the pan… heads … and crank at times if they don’t have a good seal.

As for the rotors. Rust build up is normal and if you have water somehow get on the rotors after a long drive they car get surface rust quickly. It’s not an issue it happens to every car. The rust is scrubbed off the first time you hit the breaks. It’s normal

On the v10 it seems to like to eat injectors if you don’t have the car carbon leaned often. One way to combat this is to make sure to add a good fuel injection cleaner every few tanks of gas

As for the fuel. How old is the fuel filter. Fuel filters are general maintenance parts. So you want to change them every few years.

Cold start rough running is almost a combination of a few things. Carbon…injectors that are dirty. General Sai cold start running. This is the system that’s runs to warm up the cats. It always seems to make every ones car run rough in cold weather.

I would look at the suspension including the end links and control arms. It could also be the exhaust hitting on the drive shaft at low speeds. This can happen from time to time when people modify there stock cat back exhaust and the hangers are not adjusted.

I think that’s most of the questions

#3

I try to use only Chevron, as I have the best luck with them. Costco claims they have top tier but my car didn’t run as well when I was using their gas. Shell is probably safe but I haven’t tried them over Chevron yet. I use Techron (that I ironically get from Costco in packs of 6 lol) every few months now after getting a carbon cleaning done a while ago.

What is General Sai? Will the cold weather cause any permanent damage that is preventable or is it just something that happens in cold weather?

Also, I do have a muffler delete. Would that cause the contact you were talking about?

#4

Oil pan replacement was supposed to clear up the issue with the smoke, but did not. I’ve included a video to show as best I can what it looks like and where it’s coming from. The smoke only ever comes from the driver side of the engine bay. Let me know if you can’t view the video.

https://onedrive.live.com/redir?resid=9A90E5A8422EE8CC!5555&authkey=!ANWWx39IsO_sB-E&ithint=folder%2Cmp4 Microsoft OneDrive link

Potentially unrelated, at high RPM’s (6k if I recall correctly), the car threw a code for Low Fuel Rail Pressure. Also showed misfire for cylinders 2 and 9 I believe. I took it to the shop foreman of the dealer I service my car at and he said the cylinder positioning doesn’t really indicate anything in itself, but it seems to me that these are both the same cylinder in terms of “firing order”, just reversed, so I feel that it could be related? He said to keep an eye on it to see if it starts driving weird, and it hasn’t (except at those high RPM’s). Not necessarily related to the smoke, but I’ve seen this code only once before, nearly a year ago I believe. Maybe it has something to do with the weather as I believe the timing could be similar, and I only saw the code once (this is the second occurrence).

Thanks again guys.

#5

I got a chance to watch the video one time and then after that it never worked. It loads but no video plays or it plays up to the point where you open the door.

From what Isaw thatss a constant amount of smoke. If you take off the oil cap while the car is running will the smoke slow down or stop.

Also will it smoke like that all the time or you did you need to really beat on the car to get the smoke to come out like that.

#6

Thought I replied to this, I must not have hit post…

I’ll have to test the oil cap thing next chance I get. The smoke is for no more than 5 minutes, and only appears after “spirited” driving. Generally if I’m going over 100 mph I’ll definitely notice it depending on how much time it is until I stop (obviously can’t see it unless I’m stopped). It may also happen at low speeds under extended heavy acceleration, but I’m not 100% sure. With the misfires happening at high rpm’s again, I can’t test it until I get it fixed. I’m dropping it off this Tuesday. My sense of smell is pretty bad due to allergies and stuff, but I swear it smells like burning rubber.

I’ll see if I can upload the video to the site.

#7

See if you can load the video to the site. Just use the load tab in the upper right hand side of the page.

Also one big thing we want to start telling every v10 guy is start using inector cleaner.

#8

Will do on both fronts.

What kind of injector cleaner(s) should I use and how often? If you could be as basic as possible that’d be awesome (e.g. gas tank level, how to drive the car while running the cleaner, whether it’s cold outside has a factor or not, stuff like that).

#9

Uploaded just now under Zip Technical and DIY

#10

The type is really up to you. I like redline as its the most powerful according to some tests. Stuff like seafoam is ok but some say its too harsh. You need to be careful as there is a ballance between a good cleaner and something too rough that it does damage to the cats.

I would suggest doing on each tank for a few months. Driving wise. Just do your normal driving. After a few months maybe a few good WOT pulls would be a good idea

#11

Car has been in the shop for the last week and a half or so fixing a fuel leak. I’m thinking this may be causing the issue but I guess we’ll see.

Sounds good, I’ll take a look at some different ones and go from there.

#12

I would tend to think this isnt a fuel issue as far as the smoke is concerned. If it was fuel chances are it would have been flames not smoke