Oil meter reading vs dip stick reading
11-22-2006, 05:18 PM
#1
Nordschleife Master
Thread Starter
Oil meter reading vs dip stick reading
Hi guys,
I've been comparing the oil meter reading and dip stick reading of my car and found they are consistently off from each other. The meter always reads low.
I measure the oil level at exactly 10 minutes after the car is stopped at the same spot in my garage (after being driven to operating temp). The dip stick reads 50% (right between the min and max marks) but the oil meter shows only 1bar (the lowest bar). When the meter reads full, the dip stick shows 1/4" over the max mark. Is that typical? I tend to trust the dip stick more...
- Ahsai
I've been comparing the oil meter reading and dip stick reading of my car and found they are consistently off from each other. The meter always reads low.
I measure the oil level at exactly 10 minutes after the car is stopped at the same spot in my garage (after being driven to operating temp). The dip stick reads 50% (right between the min and max marks) but the oil meter shows only 1bar (the lowest bar). When the meter reads full, the dip stick shows 1/4" over the max mark. Is that typical? I tend to trust the dip stick more...
- Ahsai
11-22-2006, 07:56 PM
#4
1/2 a quart is only 5-6% of our oil I would not be concerned. The dipstick or the guage could be off that much too. I think the only way to know (maybe) is to do your own oil changes.
Len
Len
11-22-2006, 08:40 PM
#5
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Let’s look at your 996’s dash gauge and try to figure out what it’s telling us.
Porsche says the distance between the maximum and the minimum marks on the digital oil gauge represents about 1.5 liters or 1.585 quarts of oil. There are six lines between those two marks, so each line represents about 0.246 quarts of oil.
Porsche also says to add a half a liter of oil at a time. For our purposes, let’s call it a half a quart. Therefore, we can let the oil level drop two lines on the gauge before adding a half quart of oil. I would not bother to add oil in smaller quantities, as you will only confuse yourself — and probably the car, as well.
How you check your oil level will result in different readings. When you check the engine oil cold, you will get a higher reading than with the other methods. All of the oil has run back into the sump, resulting in this higher reading.
With the various warm-check procedures, there is always going to be some oil off in the far corners of the engine, so you will get a resulting lower reading. We know that Porsche wants you to check the oil level when the car is parked on level ground and not running. And, as you may know, there are four different ways to check it:
1. With the engine cold when you turn the ignition key to “Accessory.”
2. By switching a warm engine off then turning the key back on and waiting for the timer to run down to zero.
3. What Porsche calls the automatic oil level measurement when you are fueling. The motor must be warm. This presumes the engine is shut off for a few minutes (about five) but less than 15 minutes. When you turn the key back on, the measured oil level is displayed for approximately one minute.
4. The old fashioned way, with the dipstick (for all but 996 Turbos).
I prefer to check the oil when it’s cold in my cars because the reading is more consistent when the engine is cold than with the other various methods. If the level is less than one line down, I essentially ignore it as well as the other readings and check the engine oil level cold before I drive my 996 again.
Once the level drops to the first line below maximum, I pay more attention to the other readings.
When the other checks indicate two lines below the maximum level, I add a half a quart of oil.
Hope that makes sense!
Chris.
Porsche says the distance between the maximum and the minimum marks on the digital oil gauge represents about 1.5 liters or 1.585 quarts of oil. There are six lines between those two marks, so each line represents about 0.246 quarts of oil.
Porsche also says to add a half a liter of oil at a time. For our purposes, let’s call it a half a quart. Therefore, we can let the oil level drop two lines on the gauge before adding a half quart of oil. I would not bother to add oil in smaller quantities, as you will only confuse yourself — and probably the car, as well.
How you check your oil level will result in different readings. When you check the engine oil cold, you will get a higher reading than with the other methods. All of the oil has run back into the sump, resulting in this higher reading.
With the various warm-check procedures, there is always going to be some oil off in the far corners of the engine, so you will get a resulting lower reading. We know that Porsche wants you to check the oil level when the car is parked on level ground and not running. And, as you may know, there are four different ways to check it:
1. With the engine cold when you turn the ignition key to “Accessory.”
2. By switching a warm engine off then turning the key back on and waiting for the timer to run down to zero.
3. What Porsche calls the automatic oil level measurement when you are fueling. The motor must be warm. This presumes the engine is shut off for a few minutes (about five) but less than 15 minutes. When you turn the key back on, the measured oil level is displayed for approximately one minute.
4. The old fashioned way, with the dipstick (for all but 996 Turbos).
I prefer to check the oil when it’s cold in my cars because the reading is more consistent when the engine is cold than with the other various methods. If the level is less than one line down, I essentially ignore it as well as the other readings and check the engine oil level cold before I drive my 996 again.
Once the level drops to the first line below maximum, I pay more attention to the other readings.
When the other checks indicate two lines below the maximum level, I add a half a quart of oil.
Hope that makes sense!
Chris.
11-22-2006, 10:13 PM
#6
Nordschleife Master
Thread Starter
Hi Chris,
Thanks for the detail explanation and info. In my case, believe it or not, I got same measurements either 10 minutes after shut-off or when the engine is cold. My guess is oil does expand when hot so that compensates for the residual oil that has not drained back to the sump. Also, 10 minutes seem to be enough for HOT oil to drain back.
I prefer measuring it hot since that's the oil level the engine will "see" (at operating temp). My concern is more about the decrepancy between the meter and the dipstick readings.
- Ahsai
Thanks for the detail explanation and info. In my case, believe it or not, I got same measurements either 10 minutes after shut-off or when the engine is cold. My guess is oil does expand when hot so that compensates for the residual oil that has not drained back to the sump. Also, 10 minutes seem to be enough for HOT oil to drain back.
I prefer measuring it hot since that's the oil level the engine will "see" (at operating temp). My concern is more about the decrepancy between the meter and the dipstick readings.
- Ahsai
11-22-2006, 11:34 PM
#7
Rennlist Member
Originally Posted by cdodkin
4. The old fashioned way, with the dipstick (for all but 996 Turbos).
