When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Well, I am about to make my first large repair to my beloved S8. About a month ago I reported to the forum that I was attempting to repair my lower oil pan that was leaking. During some pretty weather I got her up on stands and started into the project. Removed the protective covers, wiped everything down and was fairly certain I had identified the leak. So here we go with amateur driveway repairs. Removing the oil pan is very simple and straight forward until you arrive at the bolts across the back row that are tucked neatly under a very sturdy and thick aluminum cross member. To access those I had to fashion a long handle open end 10mm wrench and come from back towards the back of the engine/transmission. No hill for a stepper though. After draining the oil and letting it sit overnight I removed the pan and then the fun begins. I let it drain for another night ensuring all the oil was out. I then used a razor blade to chisel off all of the old silicone gasket. Not too difficult and fairly cathartic for someone that likes this sort of thing. I had very good visibility of the machined surface of the block and had it super clean and dry of all oil. After about an hour I noticed that some oil residue had started to form at the area that I had identified the origin of the leak. I wiped it down again and let it sit for a while and came back in an hour or so only to find more oil. This time I place a small piece of cloth on the inside to help determine if the oil was coming from inside the engine block or the outside. You already know the answer. It was coming from outside and from above. Long story short, I had it flatbed towed to the repair shop for further diagnosis. Got a call at noon today with the shop owner asking me if I could come down to the shop. That's never good and we all know it. After getting it up on the rack, they had to remove the entire front bumper, radiator, condenser and here we arrive at the real culprit. The seal between the block and the upper oil pan has sprung a significant seep/leak. Enough to warrant a repair as it leaks down and starts to blow back across everything making quite a mess. So, with a quote of $2800.00 (and that's with about a $700.00 discount) I gave them the go ahead. In order to fix this the whole dang motor basically has to come out to get to everything. Arrrggghhhhh !!!!!! The upside to this debacle is that they are gonna allow me to come down and replace my rotors and pads while its on the rack. Generous of them. Most places wont let ya step foot in their work area for insurance fears. Lastly, they could tell the front end had been off the car previously as it was missing a stud that holds the front bumper on and broken tube to the left airbox that would only be this way with a full "front off access" procedure. The book quotes 29 hours of labor to get this job done but they are working with me. As the icing on the cake, the tow truck drive damaged the condenser with the chain as he drug it up onto the flatbed. They get to fix that!!! Gonna be outta service for about 10 days as this all comes together.
Yes, that's unfortunate. Chance to look at other suspect areas.
I know from pulling the lower pan even on my 2000 C5 4.2 with the common engine cradle/subframe set up, that if that upper pan area is compromised, the motor basically has to come out, or the whole lower frame dropped away while the motor is supported to get at it.
Since you will also be at the shop nursing the baby back to health, you might take a look at anything known to be an S8 issue that is super problematic to get to and you could access better here. Depends on miles too. Sub 80-100K I wouldn't be looking for lots of new issues, but by about 100K I would be thinking about anything pre emptive. For example, several have reported issues with 02's, including the always tough to deal with post cat ones. I have some sense maybe the rear cylinder forward ones may be in a tough place too from what people post. W12 pre cat ones are all accessible (contra old web "truths"), but post cats would be in "step one, pull motor" territory. Have you ever had any 02 related codes?
Another could be lower suspension arms given the attachment points, but those don't seem to wear to any significant extent. Also look carefully at the front torque motor mount (besides the main two). Very hard to get at on W12's. Did my C5 4.2 fairly easily, but only because I had the passenger head off and all the timing belt related drive stuff. The torque mounts crack open and leak a brownish oil. They crack all the way around it and the oil stains around or below it are the give aways. Motor shakes a bit more when the torque mount goes, and it in turn can compromise the main mount longevity. Also the ever popular $25 coolant sensor; don't know where that is on S8. On 4.2 it is awkward and buried. On W12 it is just one step under pull motor (which is the official Bentley line). BTDT in last few weeks with only intake off, barely.
Good luck on the repairs. Consider a post here and any other similar boards like QW asking the general question for those with the V10, what repairs have come up that need a motor or near motor pull? Maybe the C6 board too given the V10 is even more tightly shoehorned in to that one. What ever gets flagged, thats a possible suspect list.
Good thinking. My car only has 72K on it and they have been looking around for other stuff that's not up to par. Good idea to post over on the S6 forum since as you stated its shoehorned into an even tighter spot. I hear people complain about not being able to get to anything with these cars because of the way things are packaged but I cannot imagine any other way of jamming all this stuff into a small area without actually making it a bigger area.........defeating the point of course. In any case, with the whole front end off you sure can see a lot better and it gives you a much better visual for where things are and how to possibly get to them later. I don't wanna make a habit of pulling the front end off the car and dropping the motor. Bentley says its a 29.5 hour job and at roughly 100 bucks an hour, that's 3K every time. Not a fun way to spend 3K........I'd rather buy tires , exhaust, wheels........anything but pure labor.
In addition, I would look higher the upper oil sump - bedplate, which contains main bearings caps and high and low pressure oil passages - looks like oil leaks originate from there too on both sides. :-(
Misha may be on to something. I think I remember a post where somebody with an S8 had a bunch of blown seal issues. If I remember right, it maybe had something to do with the oil vapor system somehow, which pressurized the motor and then all hell broke loose. Can try searching for posts. You might also simply take off the oil cap with motor running briefly and make sure you don't have some obvious pressure blow off. To be careful and since it connects directly with the oil, carefully inspect the whole oil vapor system--lines clear, nothing broken, no signs of over pressurization, suck valve (the weird Y thing so many Audis have) in order, world's most expensive way overdone PCV valve at least the 4.2's have is functioning (not sure my W12 has that; it has oil separator boxes on each side near throttle bodies that may integrate that function), etc.
All, thanks for the input. According to the shop this is the origin of the leak and its not pouring out or blowing out. Its a significant seep that has accumulated over time and it coagulates when the engine isn't warm. It only trails down when hot and takes quite a while to result in drips in the driveway. Of course it needs to be fixed once we are this far in but to start preemptively replacing things unless its clearly in need doesn't seem like the right thing to do. MP, I have that SSP and will be digging into as a learning tool for sure. In terms of the O2 sensors, I've not had a in issues with those but if they require the full drop to get at them in the event of failure, then its prolly a good idea. The starter hasn't given me any issues and doesn't labor when starting. I think I am in pretty good shape beside this compromised upper seal. Someone else suggested redoing all the seals which seems like asking for trouble if they are not compromised. I would think you could end up with more leaks if you start messing around with unsealing the whole block. Its hard for me to imagine that humans could lay a bead of silicone that would be better than that of the robots that these were assembled with originally. Just a thought anyway.
Pashamad, I cannot open the link to the photos you posted. My company PC software is blocking the site for some reason. Any other way I can see them?
hunterp27 wrote: Pashamad, I cannot open the link to the photos you posted. My company PC software is blocking the site for some reason. Any other way I can see them?
I've sent you an E-mail named "link" - if it doesn't work - try another comp, IMHO.
Anyone else was able to open my link?
01-16-2015, 04:51 PM
Huge bummer S8 upper oil pan leak
