As the subject says, my car suddenly went from using 1 qt every 4-5k miles to 1 qt every 1k miles. No leaks and it seems to be blowing smoke between shifts, so I'm guessing it's probably the valves. Guess I shouldn't be too concerned as it does have 277,000 miles on it. But the interesting thing is that I was always using GC 0w30 until last oil change when I switched to Castrol 5w40. Theoretically, this change to a thicker oil should REDUCE consumption, so I'm just wondering if it's just coincidence or somehow related. Thoughts?
Sudden increase in consumption? 2000 Audi S4
- Thread starter PaJohn
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Change the PCV valve before you think about spending more dough. I would also be using a cheaper oil since you are adding between OCI's.
Originally Posted By: PaJohn
As the subject says, my car suddenly went from using 1 qt every 4-5k miles to 1 qt every 1k miles. No leaks and it seems to be blowing smoke between shifts, so I'm guessing it's probably the valves. Guess I shouldn't be too concerned as it does have 277,000 miles on it. But the interesting thing is that I was always using GC 0w30 until last oil change when I switched to Castrol 5w40. Theoretically, this change to a thicker oil should REDUCE consumption, so I'm just wondering if it's just coincidence or somehow related. Thoughts?
Oil consumption can be due to a variety of things. Thicker oil may or may not help.
Sometimes, aeration in the sump can cause the oil to expand and raise crankcase pressure abnormally. If that's the case, thicker oil might increase consumption since it doesn't release trapped air as easily.
It's also possible that the chemical composition of the Castrol Syntec 5w-40 simply isn't as well suited to your application; for example, maybe you have some fuel dilution that GC can withstand but Syntec 5w-40 cannot. Viscosity in and of itself may not be a factor.
My car consumes quite a bit of oil; I've seen anywhere from 1 qt/1600 miles to 1 qt/600 miles. So far, my best numbers have been with oils that were on the thin end of the spectrum but stoutly formulated (Motul X-Max 5w-30 and RLI BioSyn SHP 0w-30). The 5w-40s I've tried all did worse. The 5w-40 I'm using now might buck that trend, though, so we'll see...
My brother's Integra, on the other hand, seems to get its best consumption numbers with thicker oil.
As with all things, there really is no way to know without testing.
As the subject says, my car suddenly went from using 1 qt every 4-5k miles to 1 qt every 1k miles. No leaks and it seems to be blowing smoke between shifts, so I'm guessing it's probably the valves. Guess I shouldn't be too concerned as it does have 277,000 miles on it. But the interesting thing is that I was always using GC 0w30 until last oil change when I switched to Castrol 5w40. Theoretically, this change to a thicker oil should REDUCE consumption, so I'm just wondering if it's just coincidence or somehow related. Thoughts?
Oil consumption can be due to a variety of things. Thicker oil may or may not help.
Sometimes, aeration in the sump can cause the oil to expand and raise crankcase pressure abnormally. If that's the case, thicker oil might increase consumption since it doesn't release trapped air as easily.
It's also possible that the chemical composition of the Castrol Syntec 5w-40 simply isn't as well suited to your application; for example, maybe you have some fuel dilution that GC can withstand but Syntec 5w-40 cannot. Viscosity in and of itself may not be a factor.
My car consumes quite a bit of oil; I've seen anywhere from 1 qt/1600 miles to 1 qt/600 miles. So far, my best numbers have been with oils that were on the thin end of the spectrum but stoutly formulated (Motul X-Max 5w-30 and RLI BioSyn SHP 0w-30). The 5w-40s I've tried all did worse. The 5w-40 I'm using now might buck that trend, though, so we'll see...
My brother's Integra, on the other hand, seems to get its best consumption numbers with thicker oil.
As with all things, there really is no way to know without testing.
Originally Posted By: Radman
I would also be using a cheaper oil since you are adding between OCI's.
Strongly disagree. It's not a good idea to mess around with this application. Besides, "cheaper" oil (not in cost but in formulation) might be the whole problem in the first place.
I would also be using a cheaper oil since you are adding between OCI's.
Strongly disagree. It's not a good idea to mess around with this application. Besides, "cheaper" oil (not in cost but in formulation) might be the whole problem in the first place.
Thinner oil actually reduces consumption when its the rings. But I suspect that large an increase has nothing to do with the oil.
Originally Posted By: Gene K
Thinner oil actually reduces consumption when its the rings. But I suspect that large an increase has nothing to do with the oil.
I though that thinner oil helps if that's valve seats that are worn, and thicker oil reduces consumption when piston rings are worn. I might be wrong though...
Thinner oil actually reduces consumption when its the rings. But I suspect that large an increase has nothing to do with the oil.
I though that thinner oil helps if that's valve seats that are worn, and thicker oil reduces consumption when piston rings are worn. I might be wrong though...
Smoking on shifts (or just deceleration) says "rings" to me. The sudden onset might mean you actually cracked an oil control ring. or maybe just gummed it up badly (did you idle the car a lot recently?) If its rings, I agree with Gene that thinner oil probably will help more than thicker oil, but it probably just won't make much difference at all.
That said, it sure could be a PCV valve problem too, so try the cheap things first.
That said, it sure could be a PCV valve problem too, so try the cheap things first.
Compression/leakdown test.
Thanks everyone. Going to try replacing the PCV hose. but that's like $150 so I may try a catch can insead. Also, I had some AutoRX laying around so I changed the oil to T6, new filter, and dumped in about 21oz of RX just in case it is gummed up rings.
I really don't think leak down test will show anything as it runs and idles just fine. Besides, did a leak down a few months back and everything was well within specs.
I really don't think leak down test will show anything as it runs and idles just fine. Besides, did a leak down a few months back and everything was well within specs.
Either-way, an Audi S4 with 277K is impressive. Don't feel to bad if its time to let her go-
I barely squeaked out 154K on my A4 and It was a gentle 1 owner car. Maintenance was unbearable.
I barely squeaked out 154K on my A4 and It was a gentle 1 owner car. Maintenance was unbearable.
Originally Posted By: d00df00d
Originally Posted By: Radman
I would also be using a cheaper oil since you are adding between OCI's.
Strongly disagree. It's not a good idea to mess around with this application. Besides, "cheaper" oil (not in cost but in formulation) might be the whole problem in the first place.
If your car with 277K miles were using a quart per 1K miles you would buy expensive oil? Your wallet must be a whole lot bigger than mine.
Originally Posted By: Radman
I would also be using a cheaper oil since you are adding between OCI's.
Strongly disagree. It's not a good idea to mess around with this application. Besides, "cheaper" oil (not in cost but in formulation) might be the whole problem in the first place.
If your car with 277K miles were using a quart per 1K miles you would buy expensive oil? Your wallet must be a whole lot bigger than mine.
1. The B5 Audi S4 has a twin-turbo engine in a very cramped engine bay. Heat is a very serious issue. The last thing you want to do is use an oil that can't stand up to the stress.
2. Mileage is irrelevant. What matters is that the OP wants to keep his car.
3. The oil consumption was fine until the OP switched oils. It might be unique to that one oil, and switching back to GC might fix it. Even if it doesn't, there might be a PCV issue that is easily fixed.
Imagine if you were cleaning your house and kicked up a bunch of dust in the process, and your dog sneezed. Then imagine thinking to yourself, "well, he's obviously infirm, so there's no reason to feed him good food and clean water; I'll just let him eat sawdust and drink out of the toilet from now on." That's what "cheap oil" advice is like in this scenario.
2. Mileage is irrelevant. What matters is that the OP wants to keep his car.
3. The oil consumption was fine until the OP switched oils. It might be unique to that one oil, and switching back to GC might fix it. Even if it doesn't, there might be a PCV issue that is easily fixed.
Imagine if you were cleaning your house and kicked up a bunch of dust in the process, and your dog sneezed. Then imagine thinking to yourself, "well, he's obviously infirm, so there's no reason to feed him good food and clean water; I'll just let him eat sawdust and drink out of the toilet from now on." That's what "cheap oil" advice is like in this scenario.
Originally Posted By: d00df00d
Imagine if you were cleaning your house and kicked up a bunch of dust in the process, and your dog sneezed. Then imagine thinking to yourself, "well, he's obviously infirm, so there's no reason to feed him good food and clean water; I'll just let him eat sawdust and drink out of the toilet from now on." That's what "cheap oil" advice is like in this scenario.
Except the dog LIKES drinking out of the toilet...
(at least mine does)
Imagine if you were cleaning your house and kicked up a bunch of dust in the process, and your dog sneezed. Then imagine thinking to yourself, "well, he's obviously infirm, so there's no reason to feed him good food and clean water; I'll just let him eat sawdust and drink out of the toilet from now on." That's what "cheap oil" advice is like in this scenario.
Except the dog LIKES drinking out of the toilet...
(at least mine does)
UPDATE - So I've put about 400 miles on the car since putting in the T6 (with ARX) and the level has barely dropped. Maybe 1/8" lower on the DS if that. Do you think maybe it just didn't like the switch to Castrol 5w40?
Possibly. Some motors just seem to do better on some oils. Perhaps it's some weird coming-together of the add pack in a certain motor's condition.
LOL, brand dis-loyalty like that is so silly.
it might be time for Italian tune up. GC is a good oil I would stick with that.
Originally Posted By: zoomzoom
it might be time for Italian tune up. GC is a good oil I would stick with that.
Italian tuneup ? I think proper diagnosis of the situation is required here rather than thrashing the guts out of a tired engine.
Please clarify. Did the oil consumption increase with thre change to 5w40 oil ?
Auto-RX I would NOT bother, if you have been using GC 0w30, the engine should be pretty clean, including the ring pack.
At 277k gaskets are probably too old to rejuvenate, Auto-RX overated stuff anyway IMO.
it might be time for Italian tune up. GC is a good oil I would stick with that.
Italian tuneup ? I think proper diagnosis of the situation is required here rather than thrashing the guts out of a tired engine.
Please clarify. Did the oil consumption increase with thre change to 5w40 oil ?
Auto-RX I would NOT bother, if you have been using GC 0w30, the engine should be pretty clean, including the ring pack.
At 277k gaskets are probably too old to rejuvenate, Auto-RX overated stuff anyway IMO.
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