DIY- Percentage of DIRTY OIL after an OIL CHANGE
06-30-2013, 12:05 AM
#1
Burning Brakes
Thread Starter
DIY- Percentage of DIRTY OIL after an OIL CHANGE
How much dirty oil is left when the transmission, power steering, and engine oil is drained/ changed?
OK, I was bored, actually, I was supposed to be doing something else, which was boring, when I wrote this.
Any time that any fluid is drained from any vehicle module, you must check the fluid level after refilling, and top-up if necessary.
The FSM (factory service manual) specifies the amount of fluid contained in each serviceable vehicle module: engine, transmission, power steering system, etc. However, the base fluid volume is given in metric values, and then converted to English values, with rounding. Because of the rounding, and because of manufacturing and assembly tolerances, any fluid volume specified by the FSM is only an estimate.
Also, the FSM states that before draining any module, the oil should be warmed: warm the engine, warm the transmission, etc. This decreases the drain time, increases the amount of fluid drained, and improves the amount of wear material removed, because the wear material is better suspended in warm oil, than is cold oil.
DANGER:
When servicing any part of your vehicle, take care when lifting any part of the vehicle, as serious personal injury may result if the vehicle falls.
TRANSMISSION
Amount of old ATF remaining after each drain-and-fill of 4-qts
1) 4qts – 50%
2) 2qts – 25%
3) 1qt - 12.5% ***
4) 0.5qt - 6.2%
5) 0.25qt/ 8ounces - 3.1%
6) 0.12qt/ 4ounces - 1.5%
The FSM says drain and refill with 3.5 qts of new ATF. Remember that the level marks on the transmission dip-stick, represent an amount of 8-ounces.
I generally drain the ATF after driving at least 7 miles (my commute), so the oil is warm. And allow the trans to drain for at least 30-minutes. Almost always slightly more than 4-quarts are drained, as much as 10-ounces more than 4-qts.
For these reasons, it is very important to carefully measure the exact actual amount of ATF that is drained, and replace with that same exact amount of ATF.
HOW TO COMPUTE THE OLD PERCENTAGE OF ATF:
The FSM states that the transmission holds 8.2-quarts of ATF. But for the sake of simplicity, assume that the actual amount is 8.0-quarts. And also assume that 4.0-quarts is the actual amount of ATF that will be drained from the trans.
Then each time the trans is drained, exactly 1/2 (or 50%) of the old fluid in the trans will be drained. Then computing how much old fluid remains inside the trans, is quite easy, and pretty accurate to within a few ounces, which is really irrelevant.
So the table shown above is really true, even if it seems odd. Yes, on the fourth drain-and-fill, you will drain out 4-quarts from the trans, and refill with 4-quarts of new fluid. Yet, only 1/2-quart (0.5) of old fluid will be removed from the trans. The other 3.5-quarts drained will be the new oil you added in the first three drain-and-fills.
So, removing that last 1-quart of old fluid, that remains after 3-drain-and-fills, requires a lot of new ATF. It is not worth the time and cost. So wait until the trans ATF requires refreshing again, at the next drain interval.
POWER STEERING
Use a turkey baster, or battery-fill bulb, to suck out the PS fluid. This table should indicate why it is better to flush out all of the PS fluid at one time. Otherwise, you must use the turkey-baster type drain-and-fill on a short regular basis. While only three cycles (drain-and-fill) will remove almost 60% of the old fluid, another three cycles will remove only another 20%, or 80% total. So unless the drain-and-fill cycles are short, old oxidized oil will build up in the PS fluid tank.
Amount of old PSF remaining after each drain-and-fill of 7-ounces
1) 24.0 ounces – 75%
2) 18.0 ounces – 56%
3) 13.5 ounces - 42% ***
4) 10.1 ounces - 32%
5) 07.6 ounces - 24%
6) 05.7 ounces - 18%
7) 04.3 ounces - 13%
8) 03.2 ounces - 10%
9) 02.4 ounces – 7.5%
When ‘draining’ the Power Steering tank, do not push anything against the internal filter-screen in the bottom of the tank. It is only a plastic screen-mesh, and can be damaged by poking a hole in it. If the fluid level is at the top fill-mark, then probably no more than 7 ounces can be removed from the tank, without damaging the internal tank screen.
There is no reason to ‘air-bleed’ the system after this type of drain-and-fill, as the fluid level is not lowered below the level of the lower PS tank/ pump intake hose. No air is introduced into the system. Do not start the engine until the PS tank is refilled.
In order to *mix* the new PSF with the existing fluid, the vehicle must be driven a few miles, and the steering turned a few times. Do *NOT* under any circumstances, turn the steering wheel while the vehicle is stationary. And do not hold the steering against the steering lock, as that can damage the pump, the rack, or blow (rupture) one of the hoses (big leak) – read your Owner’s Manual.
HOW TO COMPUTE THE OLD PERCENTAGE OF POWER STEERING FLUID:
The situation is the same as when you drain-and-fill the transmission: see section above. Except that less PSF can be removed at each time. Lets cheat again, round off the fluid amounts, and get an easy way to compute the percentages. The computational difference even after 8 drain-and-fills, will be about 1/2-ounce.
The FSM states that the PS tank holds 0.96-quarts. So assume that it actually holds 1-quart or 32-ounces. And assume that each drain-and-fill removes 8-ounces. So 1/4 (25%) of the old fluid is removed each time, leaving 3/4 (75%) of the old fluid in the tank.
So yes, each cycle removes both old and new fluid. The third cycle will remove 25% (4.5ounces) of the old fluid remaining after the second cycle, which is 56% = 18ounces, as well as 25% (3.5ounces) of the new fluid added (14ounces) with the first two cycles. That is why it is so difficult to remove all of the old fluid by this method.
NOTE: you can overfill the PS tank by one ounce, so that you can remove 8 ounces instead of only 7 ounces. But do *not* overfill by more than 1-ounce, as the excess will only ‘puke’ out during driving.
ENGINE OIL
NEW FILTER: Amount of old OIL remaining after each drain-and-fill
1) 32ounces – 16.6%
2) 5.3ounces – 2.8%
RETAIN CURRENT FILTER: Amount of old OIL remaining after each drain-and-fill
1) 32ounces + 8ounces – 21.0% (retain filter)
2) 6.7ounces – 3.5% (change filter)
The FSM states that the engine/ turbo system holds 6-quarts of oil, but only 5-quarts can be drained (if the filter is also replaced).
If the filter is *not* replaced, the FSM says only 4.8-quarts can be drained. Actually, I have found that only about 4.6-quarts of oil can be drained, depending upon the brand of filter, and because the oil-gallery to the filter cannot drain.
In other words, between 8-ounces and 12-ounces of oil will *not* be drained, if the filter is not replaced. I suggest that you refill with only 4.5-quarts, and then later check for any required top-up.
HOW TO COMPUTE THE OLD PERCENTAGE OF ENGINE OIL:
Well, because at least 1-quart of old oil is left in place during an oil change, I change the oil at around 40% of oil life by the MID. You can decide for yourself when to change the oil in your own vehicle.
Whether or not the oil filter is replaced, the amount of old oil remaining in the filter, is not significant enough to worry about. While I generally replace the filter at each oil-change, when the outside temp is only 30-degrees, I just leave my 15K-mile extended performance Mobil-1 oil-filter in place until the next oil change.
-----eof
OK, I was bored, actually, I was supposed to be doing something else, which was boring, when I wrote this.
Any time that any fluid is drained from any vehicle module, you must check the fluid level after refilling, and top-up if necessary.
The FSM (factory service manual) specifies the amount of fluid contained in each serviceable vehicle module: engine, transmission, power steering system, etc. However, the base fluid volume is given in metric values, and then converted to English values, with rounding. Because of the rounding, and because of manufacturing and assembly tolerances, any fluid volume specified by the FSM is only an estimate.
Also, the FSM states that before draining any module, the oil should be warmed: warm the engine, warm the transmission, etc. This decreases the drain time, increases the amount of fluid drained, and improves the amount of wear material removed, because the wear material is better suspended in warm oil, than is cold oil.
DANGER:
When servicing any part of your vehicle, take care when lifting any part of the vehicle, as serious personal injury may result if the vehicle falls.
TRANSMISSION
Amount of old ATF remaining after each drain-and-fill of 4-qts
1) 4qts – 50%
2) 2qts – 25%
3) 1qt - 12.5% ***
4) 0.5qt - 6.2%
5) 0.25qt/ 8ounces - 3.1%
6) 0.12qt/ 4ounces - 1.5%
The FSM says drain and refill with 3.5 qts of new ATF. Remember that the level marks on the transmission dip-stick, represent an amount of 8-ounces.
I generally drain the ATF after driving at least 7 miles (my commute), so the oil is warm. And allow the trans to drain for at least 30-minutes. Almost always slightly more than 4-quarts are drained, as much as 10-ounces more than 4-qts.
For these reasons, it is very important to carefully measure the exact actual amount of ATF that is drained, and replace with that same exact amount of ATF.
HOW TO COMPUTE THE OLD PERCENTAGE OF ATF:
The FSM states that the transmission holds 8.2-quarts of ATF. But for the sake of simplicity, assume that the actual amount is 8.0-quarts. And also assume that 4.0-quarts is the actual amount of ATF that will be drained from the trans.
Then each time the trans is drained, exactly 1/2 (or 50%) of the old fluid in the trans will be drained. Then computing how much old fluid remains inside the trans, is quite easy, and pretty accurate to within a few ounces, which is really irrelevant.
So the table shown above is really true, even if it seems odd. Yes, on the fourth drain-and-fill, you will drain out 4-quarts from the trans, and refill with 4-quarts of new fluid. Yet, only 1/2-quart (0.5) of old fluid will be removed from the trans. The other 3.5-quarts drained will be the new oil you added in the first three drain-and-fills.
So, removing that last 1-quart of old fluid, that remains after 3-drain-and-fills, requires a lot of new ATF. It is not worth the time and cost. So wait until the trans ATF requires refreshing again, at the next drain interval.
POWER STEERING
Use a turkey baster, or battery-fill bulb, to suck out the PS fluid. This table should indicate why it is better to flush out all of the PS fluid at one time. Otherwise, you must use the turkey-baster type drain-and-fill on a short regular basis. While only three cycles (drain-and-fill) will remove almost 60% of the old fluid, another three cycles will remove only another 20%, or 80% total. So unless the drain-and-fill cycles are short, old oxidized oil will build up in the PS fluid tank.
Amount of old PSF remaining after each drain-and-fill of 7-ounces
1) 24.0 ounces – 75%
2) 18.0 ounces – 56%
3) 13.5 ounces - 42% ***
4) 10.1 ounces - 32%
5) 07.6 ounces - 24%
6) 05.7 ounces - 18%
7) 04.3 ounces - 13%
8) 03.2 ounces - 10%
9) 02.4 ounces – 7.5%
When ‘draining’ the Power Steering tank, do not push anything against the internal filter-screen in the bottom of the tank. It is only a plastic screen-mesh, and can be damaged by poking a hole in it. If the fluid level is at the top fill-mark, then probably no more than 7 ounces can be removed from the tank, without damaging the internal tank screen.
There is no reason to ‘air-bleed’ the system after this type of drain-and-fill, as the fluid level is not lowered below the level of the lower PS tank/ pump intake hose. No air is introduced into the system. Do not start the engine until the PS tank is refilled.
In order to *mix* the new PSF with the existing fluid, the vehicle must be driven a few miles, and the steering turned a few times. Do *NOT* under any circumstances, turn the steering wheel while the vehicle is stationary. And do not hold the steering against the steering lock, as that can damage the pump, the rack, or blow (rupture) one of the hoses (big leak) – read your Owner’s Manual.
HOW TO COMPUTE THE OLD PERCENTAGE OF POWER STEERING FLUID:
The situation is the same as when you drain-and-fill the transmission: see section above. Except that less PSF can be removed at each time. Lets cheat again, round off the fluid amounts, and get an easy way to compute the percentages. The computational difference even after 8 drain-and-fills, will be about 1/2-ounce.
The FSM states that the PS tank holds 0.96-quarts. So assume that it actually holds 1-quart or 32-ounces. And assume that each drain-and-fill removes 8-ounces. So 1/4 (25%) of the old fluid is removed each time, leaving 3/4 (75%) of the old fluid in the tank.
So yes, each cycle removes both old and new fluid. The third cycle will remove 25% (4.5ounces) of the old fluid remaining after the second cycle, which is 56% = 18ounces, as well as 25% (3.5ounces) of the new fluid added (14ounces) with the first two cycles. That is why it is so difficult to remove all of the old fluid by this method.
NOTE: you can overfill the PS tank by one ounce, so that you can remove 8 ounces instead of only 7 ounces. But do *not* overfill by more than 1-ounce, as the excess will only ‘puke’ out during driving.
ENGINE OIL
NEW FILTER: Amount of old OIL remaining after each drain-and-fill
1) 32ounces – 16.6%
2) 5.3ounces – 2.8%
RETAIN CURRENT FILTER: Amount of old OIL remaining after each drain-and-fill
1) 32ounces + 8ounces – 21.0% (retain filter)
2) 6.7ounces – 3.5% (change filter)
The FSM states that the engine/ turbo system holds 6-quarts of oil, but only 5-quarts can be drained (if the filter is also replaced).
If the filter is *not* replaced, the FSM says only 4.8-quarts can be drained. Actually, I have found that only about 4.6-quarts of oil can be drained, depending upon the brand of filter, and because the oil-gallery to the filter cannot drain.
In other words, between 8-ounces and 12-ounces of oil will *not* be drained, if the filter is not replaced. I suggest that you refill with only 4.5-quarts, and then later check for any required top-up.
HOW TO COMPUTE THE OLD PERCENTAGE OF ENGINE OIL:
Well, because at least 1-quart of old oil is left in place during an oil change, I change the oil at around 40% of oil life by the MID. You can decide for yourself when to change the oil in your own vehicle.
Whether or not the oil filter is replaced, the amount of old oil remaining in the filter, is not significant enough to worry about. While I generally replace the filter at each oil-change, when the outside temp is only 30-degrees, I just leave my 15K-mile extended performance Mobil-1 oil-filter in place until the next oil change.
-----eof
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