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I'm not terribly car savvy and couldn't find an answer I could wrap my head around, so I figured I'd just swallow my pride and ask.

I've started a 7k mile road trip, and I'm about 2500 miles into it. My '02 Audi S8 had the oil level indicator come on, and when I checked the oil level via the dipstick (after 3 hours of driving, so the car was definitely at operating temp but not overheating), and it was super low, i.e. below the allowable range on the dipstick.

I added 2 quarts (again, engine was fully warm), and the level is now at the middle of the stick.

Is this normal? Should I expect to add a quart or two every 1k miles or so? I just want to stay on top of it if it's expected behavior, but I don't want to overfill it.

I, admittedly, have yet to check it cold. I can do that in the morning. Any input is greatly appreciated!

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  • I should add, I had an oil change done right before starting my road trip. Put in full synthetic, and if I follow the recommended change mileage I still have about 3300 miles to go before doing a full blown oil change.
    – mrbusto71
    Aug 10, 2017 at 0:51
  • Welcome to the site. Aug 10, 2017 at 10:09
  • It's possible that the place you took it to for the oil change didn't add the right amount, did you check the oil level yourself before the trip?
    – GdD
    Aug 10, 2017 at 12:42
  • @GdD, good point. Wouldn't be the first time a lube tech didn't add the right amount, especially on a car that takes more than the average amount of oil.
    – JPhi1618
    Aug 10, 2017 at 16:21
  • It happens @JPhi1618. If it were my car I'd just keep a close eye on the level, if it keeps dropping I'd get it looked at, if not then I'd ask for my money back from the people who did the job.
    – GdD
    Aug 10, 2017 at 16:29

2 Answers 2

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From my short research on the internet, it seems the S8 is not prone to burning oil and suggests there are two ways you are probably seeing the oil consumption.

First way is leaking. That could be just about anywhere on the engine, but would most likely be pretty noticeable. Second way is if the PCV is clogged or is sucking up oil and spitting it through the intake. This seems a lot more likely, especially if you're running your S8 fairly hard.

Neither is too much to worry about right now while on your road trip (probably nothing you'd want to try to take care of, anyway) as long as you keep up with the oil consumption. Check your oil every time you fill up with fuel. Also, check it in the morning before you head out for the day. While that may seem excessive, it will allow you to stay on top of it without worry of it getting too low. My understanding is the S8 takes 8.5 quarts of oil. That's a substantial bit of oil, so nothing should have been hurt by it running down a couple of quarts. It's not good, but I doubt your car has sustained any damage.

If the car seems to start using more oil over time during your trip, you may want to have it looked at. It's not good for the catalytic converters to be dumping too much oil through them. Just be consistent as to when you check your oil and get a feel for how much it's consuming. If the amount goes up, you should know it right away. You definitely don't want to run the engine dry, that's for sure.

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It's very common for all modern Audis (and VWs) to burn oil.

There are a range of possible answers for this that you will discover on the Internet, so it depends on who you want to believe as to the cause for this. I personally think that some of the commonly suggested reasons are contributing factors, in particular: - The design of the PCV (Positive Crackcase ventilation) system, - Possibly also the choice of piston & oil control rings used in the construction of the engine.

It is very evident that these engines produce a lot of blow-by gases, increasing the amount (volume) of gases that enter the crankcase of the engine and need to be extracted from the crankcase of the engine by the PCV system. Evidence I refer to are accumulation of oil in intercooler hoses, or the intake manifold, or PCV system valve.

At the end of the day though, whatever the root causes the problem seems to result in Audi (And VW engines) consuming oil through into the intake of the engine.

Symptoms of this oil consumption include soot on the exhaust tips .. more than you might be used to appearing over time. It is also possible to see under high acceleration smoke behind the vehicle after accelerating from a standing start, particularly at night time when a vehicle's headlights behind are illuminating behind the exhaust of the car.

On FSI engines (Fuel stratified direct injection) it also results in the build up of "carbon" (as it is commonly referred to on the Internet) in the intake tracts of the engine. This is unfortunately a side-effect of the engines being direct-injection.. If the engines were a traditional port-injected engine, then the oil entering the intake ports would be dissolved continuously by the injection of fuel under normal operation of the engine. In these engines the oil seeps down the intake ports and essentially burns onto the engine head, and builds up over time. This is proof of where your oil is actually going.. it is entering the engine and being burnt off.

This results in considerable oil losses when compared to even older engines of a more traditional design.

Despite this - you may be experiencing an actual fault with your engine, but this is less likely. You could have a failure of an oil control ring which is looking and feeling like the "oil consumption" issue, however it would be more pronounced. Audi/VW do actually consider and cater for this possibility, but the amount of oil consumption in this case to warrant a warranty repair is in the extreme, as opposed to a normal oil consumption issue.

Generally speaking it is just a side-effect of the design decisions that were behind the design of these engines.. and you should just accept that these engines burn oil and top it up to the required mark at practical intervals.

To answer your questions, specifically: 1) Is this normal? Yes, unless you feel the oil consumption is considerably more than it should be, given my explanation above, which could indicate a engine issue. 2) Yes, I drive 1,000kms in Australia often and it is usually one of these trips I will find myself needing to top up about 0.5L.. so I may be adding 0.5L every couple of thousand Ks (Sorry, I don't speak imperial!)

You may like to keep more accurate records on exactly how much you lose over what distance. To do so - top up accurately to the Full mark, and 2,000 miles later or some specific distance, check and top up to exacly the same mark on the same piece of flat and level ground, cold measurement with all factors the same (tyre pressure as well so the car is the same level).

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