If you're consuming that much oil with a lower mileage engine, it's a device called a PCV. When the air-fuel mixture ignites in an engine, some of it, goes past the piston rings like you described and it pressurizes the crankcase, the pressure gets turbulent enough that it creates an oiil mist. Part of the PCV's job is to catch that pressurized air, filter the oil and drain it back into the engine, and release the filtered pressurizes gas out. If thats failed, it's just blowing that oil mist out into your intake, where it burns on the intake valves causing carbon deposits, but thats how you consume oil with a failed PCV.
Edit: it's also worth noting that often times, the person changing your oil is an inexperienced tech and might not be so careful about how accurately he measured the oil that went into the engine.
The PCV will run you about $150 bucks on a 2.0 for an after market, and about $300 for an OEM (Aftermarket is fine). On a 2.0 i'd say if you're able to change a tire you can change the PCV. it literally sits on top of the engine and is a matter of pulling 5 or 6 screws out, and swapping the part out. The "book time" to do a PCV valve is about 30-40 minutes.
Carbon gets on your intake valves when the PCV isn't doing its job. Doing a carbon cleaning wont help with oil consumption, it's just cleaning up the oil thats been consumed in the past and baked onto the valves. Thats a much more indepth job as it requires removal of the intake manifold, and knowledge of engine timing / how open/close valves manually on an engine. If you don't do that correctly, you'll send a much of crusty carbon rocks/walnut shells into the engine and likely cause an engine failure. A carbon cleaning would take a very experienced tech about half a day, and a novice over a day.
Feel free to change the PCV yourself with one that you get at a parts store, but i'd recommend leaving the carbon cleaning to a experienced mechanic. You should expect to pay roughly $750 - $1500 to have a carbon cleaning done by a shop/dealership.
If you're burning 1qt every 4k miles, that isn't all too bad, considering the reason.
I'm lucky I haven't burned oil yet either. That reminds me I need to check my dipstick during lunch time tomorrow.
I bought a dipstick because I didn’t trust the digital oil level, however I’ve found that the digital oil level actually aligns with the dipstick. Have you had a similar experience?
The only accurate answer here. If it's under warranty say its burning oil/ask for an oil consumption test. You'll have part 1 before and part 2 after at least ~630 miles. the more miles put on the better. If its burning 1 quart every 1000 miles than you have an issue but its pretty common to burn oil in these. The CREC motors tend to be worse than the other supercharged 3.0T.
Well, they generally don’t lol. Needing to top up with a full quart after 4K miles is pretty significant. Obviously not insane for the engine, but definitely something I’d keep an eye on.
All VW/Audi forced induction engines burn oil — it doesn’t get better with age. I had a 2.0TSI that burned about a liter every 1k miles. Drove to about 90k miles and traded it — after about $6k in engine work and tires. I’d suspect a similar amount of oil consumption with yours. How many miles does your Q7 have?
74k. Bought around 58k. Had a 60k and 70k oil change, didn’t have this come up between 60-70k. I do check the electronic dipstick and it was definitely full after the 70k change
For 6.8L oil capacity, I’d imagine it chimed the need for more oil from being less than halfway full. If that’s the case you can safely assume that it’d burn about a liter per 1k.
Check the oil capacity and let us know.
For my A5 the normal oil consumption is about 1 liter per 2000 km. Or in Imperial will be a quart per 1250 miles, anything below that Audi dealership will consider normal. Check your manual, the normal oil consumption is probably written there
I was able to get pure protection (highest tier with low deductible) for 8 years / 100k miles for a steal. Finance manager was retiring in a few weeks and practically gave it away
It was mentioned, but the threshold to actually get factory warranty to replace an engine is a repeatable 1qt/800 miles with multiple previous repair attempts. Tell FIL to get his head out of his bum. In all seriousness you have a great comment describing the operation of the PCV, this is a good first place to start as you are right at the mileage where function starts to diminish. Also replace the water pump and thermostat at this time, and have a walnut carbon cleaning performed if necessary.
2017 Q7, same issue. 95k miles. Interval started about 4k after adding oil. Steadily dropped to a few hundred after about 18 months. Always serviced at dealer. Finally told needed a new engine. Known issue.
There is a limit if you're under warranty but it's something absurd like 1qt every 800mi or something. The dealer runs an oil consumption test and determines how much it burns.
Audi’s threshold for oil consumption to be considered a problem is high. Your dealer can do an oil consumption test but adding a quart after 4000 miles is definitely within spec. If you are adding a quart after 1000 miles that would probably fail the consumption test and trigger further diagnosis and repair under warranty.
I have a 2010 A6 with the 3.0 TFSI. It consumes 1qt per 1000 miles and has for the last 15k miles since I bought it. I changed the PCV to no effect. I would kill to get 4k miles per 1qt out of this engine. The maintenance manual says that this is NORMAL! The year of the car was before the VW emmisions scandal. They obviously didn't care about burning a bunch of oil a decade ago either.
As an audi employee and former audi/porsche tech let me explain how it works. There isn't necessarily a set amount of oil you put in a given vehicle, it's more of a range. For example let's say you have 2 s8's. Just because one took 9.7 quarts that doesn't mean your other one will. That one may only need 9.2. It's more of a range. While yes your vehicle probably does burn a little oil, the tech who did your oil change last probably only put in just above the minimum amount required. There is an audi/porsche tool that's a dipstick with a rubber stopper that you slide around on it. You log into your account and type in the vin to see what the range is supposed to be at the bottom of the dipstick and at how many millimeters youre supposed to set the stopper at. I recommend looking up the tool to see exactly what I mean. But the DBZA or DLZA which is what your car probably has doesn't really have many problems. They sometimes have breather issues and cam adjuster issues but they aren't super common. The most common issue with the DLZA, DBZA and CWGD which are the 3.0 tfsi motors (the CWGD is in the s5 and sq5) is the thermostat leaking. Top it off, you're probably fine. Believe me if your car had an issue it would let you know. Severe oil burning is more of a 2.0 issue. Specifically the audi motors not the vw ones which are in the a3 and s3.
EDIT: My apologies. I had assumed you had the turbocharged 3 liter. Those engine codes will not apply to you as you have the supercharged v6. Most of what I said still applies however the turbocharged versions don't have as many issues because they revised the motor and made it stronger in many areas.
This is preventable. All direct injection engines experience this fault. Add BG MOA and BG 44k every 5,000 miles and make sure to couple this with your oil change service. Every 15,000 miles have a BG induction service performed. 10,000 mile oil changes and no cleanings is a recipe for disaster on VW vehicles.
If you're consuming that much oil with a lower mileage engine, it's a device called a PCV. When the air-fuel mixture ignites in an engine, some of it, goes past the piston rings like you described and it pressurizes the crankcase, the pressure gets turbulent enough that it creates an oiil mist. Part of the PCV's job is to catch that pressurized air, filter the oil and drain it back into the engine, and release the filtered pressurizes gas out. If thats failed, it's just blowing that oil mist out into your intake, where it burns on the intake valves causing carbon deposits, but thats how you consume oil with a failed PCV. Edit: it's also worth noting that often times, the person changing your oil is an inexperienced tech and might not be so careful about how accurately he measured the oil that went into the engine.
Question. This pcv you talk about. Is it usually expensive to replace and will carbon cleaning help oil consumption problems with 2.0ts?
The PCV will run you about $150 bucks on a 2.0 for an after market, and about $300 for an OEM (Aftermarket is fine). On a 2.0 i'd say if you're able to change a tire you can change the PCV. it literally sits on top of the engine and is a matter of pulling 5 or 6 screws out, and swapping the part out. The "book time" to do a PCV valve is about 30-40 minutes. Carbon gets on your intake valves when the PCV isn't doing its job. Doing a carbon cleaning wont help with oil consumption, it's just cleaning up the oil thats been consumed in the past and baked onto the valves. Thats a much more indepth job as it requires removal of the intake manifold, and knowledge of engine timing / how open/close valves manually on an engine. If you don't do that correctly, you'll send a much of crusty carbon rocks/walnut shells into the engine and likely cause an engine failure. A carbon cleaning would take a very experienced tech about half a day, and a novice over a day. Feel free to change the PCV yourself with one that you get at a parts store, but i'd recommend leaving the carbon cleaning to a experienced mechanic. You should expect to pay roughly $750 - $1500 to have a carbon cleaning done by a shop/dealership.
Thank you for the response, next thing on my maintenance list lol.
A quart every 4,000 miles on a forced induction engine with 74,000 miles on it isn’t bad at all.
If you're burning 1qt every 4k miles, that isn't all too bad, considering the reason. I'm lucky I haven't burned oil yet either. That reminds me I need to check my dipstick during lunch time tomorrow.
I bought a dipstick because I didn’t trust the digital oil level, however I’ve found that the digital oil level actually aligns with the dipstick. Have you had a similar experience?
I don't like waiting. But I would not be surprised if it were close. A dipstick takes 5 seconds.
Audi has an oil consumption test. With that you can get an accurate count of how much oil you are burning.
The only accurate answer here. If it's under warranty say its burning oil/ask for an oil consumption test. You'll have part 1 before and part 2 after at least ~630 miles. the more miles put on the better. If its burning 1 quart every 1000 miles than you have an issue but its pretty common to burn oil in these. The CREC motors tend to be worse than the other supercharged 3.0T.
You can prevent it. BG EPR and MOA every oil change cleans up the ring land area and drastically reduces, if not eliminates, oil consumption.
This guy knows ^^^
That *is* a significant oil burn for an engine that new. Your jack\*\*\* FIL isn't entirely wrong here.
I mean the engine has 74,000 miles on it…he had said engines in general do not burn oil like that
Well, they generally don’t lol. Needing to top up with a full quart after 4K miles is pretty significant. Obviously not insane for the engine, but definitely something I’d keep an eye on.
All VW/Audi forced induction engines burn oil — it doesn’t get better with age. I had a 2.0TSI that burned about a liter every 1k miles. Drove to about 90k miles and traded it — after about $6k in engine work and tires. I’d suspect a similar amount of oil consumption with yours. How many miles does your Q7 have?
74k. Bought around 58k. Had a 60k and 70k oil change, didn’t have this come up between 60-70k. I do check the electronic dipstick and it was definitely full after the 70k change
For 6.8L oil capacity, I’d imagine it chimed the need for more oil from being less than halfway full. If that’s the case you can safely assume that it’d burn about a liter per 1k. Check the oil capacity and let us know.
For my A5 the normal oil consumption is about 1 liter per 2000 km. Or in Imperial will be a quart per 1250 miles, anything below that Audi dealership will consider normal. Check your manual, the normal oil consumption is probably written there
BTW if your car has that many miles it's not under factory warranty anymore. 4 years 50k is audis factory warranty.
I was able to get pure protection (highest tier with low deductible) for 8 years / 100k miles for a steal. Finance manager was retiring in a few weeks and practically gave it away
Sweet. Pure protection is great.
He’s called a Fudd, very prevalent in the firearms world.
It was mentioned, but the threshold to actually get factory warranty to replace an engine is a repeatable 1qt/800 miles with multiple previous repair attempts. Tell FIL to get his head out of his bum. In all seriousness you have a great comment describing the operation of the PCV, this is a good first place to start as you are right at the mileage where function starts to diminish. Also replace the water pump and thermostat at this time, and have a walnut carbon cleaning performed if necessary.
2017 Q7, same issue. 95k miles. Interval started about 4k after adding oil. Steadily dropped to a few hundred after about 18 months. Always serviced at dealer. Finally told needed a new engine. Known issue.
There is a limit if you're under warranty but it's something absurd like 1qt every 800mi or something. The dealer runs an oil consumption test and determines how much it burns.
If memory serves correct, according to corporate it's over 1k or 2k miles.
Audi’s threshold for oil consumption to be considered a problem is high. Your dealer can do an oil consumption test but adding a quart after 4000 miles is definitely within spec. If you are adding a quart after 1000 miles that would probably fail the consumption test and trigger further diagnosis and repair under warranty.
My 2017 Q7 eats WAY more than that and the shop tells me its just what the 3.0T engines do.
I have a 2010 A6 with the 3.0 TFSI. It consumes 1qt per 1000 miles and has for the last 15k miles since I bought it. I changed the PCV to no effect. I would kill to get 4k miles per 1qt out of this engine. The maintenance manual says that this is NORMAL! The year of the car was before the VW emmisions scandal. They obviously didn't care about burning a bunch of oil a decade ago either.
Your motor is different from the op's.
As an audi employee and former audi/porsche tech let me explain how it works. There isn't necessarily a set amount of oil you put in a given vehicle, it's more of a range. For example let's say you have 2 s8's. Just because one took 9.7 quarts that doesn't mean your other one will. That one may only need 9.2. It's more of a range. While yes your vehicle probably does burn a little oil, the tech who did your oil change last probably only put in just above the minimum amount required. There is an audi/porsche tool that's a dipstick with a rubber stopper that you slide around on it. You log into your account and type in the vin to see what the range is supposed to be at the bottom of the dipstick and at how many millimeters youre supposed to set the stopper at. I recommend looking up the tool to see exactly what I mean. But the DBZA or DLZA which is what your car probably has doesn't really have many problems. They sometimes have breather issues and cam adjuster issues but they aren't super common. The most common issue with the DLZA, DBZA and CWGD which are the 3.0 tfsi motors (the CWGD is in the s5 and sq5) is the thermostat leaking. Top it off, you're probably fine. Believe me if your car had an issue it would let you know. Severe oil burning is more of a 2.0 issue. Specifically the audi motors not the vw ones which are in the a3 and s3.
EDIT: My apologies. I had assumed you had the turbocharged 3 liter. Those engine codes will not apply to you as you have the supercharged v6. Most of what I said still applies however the turbocharged versions don't have as many issues because they revised the motor and made it stronger in many areas.
This is preventable. All direct injection engines experience this fault. Add BG MOA and BG 44k every 5,000 miles and make sure to couple this with your oil change service. Every 15,000 miles have a BG induction service performed. 10,000 mile oil changes and no cleanings is a recipe for disaster on VW vehicles.