Is there an optimal oil level?
08-14-2018, 12:05 PM
#1
Instructor
Thread Starter
Is there an optimal oil level?
I was reading through an engine rebuild manual for how to properly maintain the engine. With respect to oil level, it was very clear that oil should be checked in the morning and should be around the middle mark. It said that if it is any higher then it is possible the oil will be over filled when engine is at operating temp. In addition, oil should not be added until the level comes down to the lower mark. Lastly, running oil near the top mark only increases the chances of consuming oil faster than if the oil was closer to the middle area.
My only question is that I like to run the oil near the top, but not over. My thinking is that the IMSB gets to sit in more oil when the car is not running. Please comment on whether this really matters or is it just fine to be anywhere as long as it is between the min and max marks?
My only question is that I like to run the oil near the top, but not over. My thinking is that the IMSB gets to sit in more oil when the car is not running. Please comment on whether this really matters or is it just fine to be anywhere as long as it is between the min and max marks?
08-14-2018, 12:08 PM
#2
Rennlist Member
I was reading through an engine rebuild manual for how to properly maintain the engine. With respect to oil level, it was very clear that oil should be checked in the morning and should be around the middle mark. It said that if it is any higher then it is possible the oil will be over filled when engine is at operating temp. In addition, oil should not be added until the level comes down to the lower mark. Lastly, running oil near the top mark only increases the chances of consuming oil faster than if the oil was closer to the middle area.
My only question is that I like to run the oil near the top, but not over. My thinking is that the IMSB gets to sit in more oil when the car is not running. Please comment on whether this really matters or is it just fine to be anywhere as long as it is between the min and max marks?
My only question is that I like to run the oil near the top, but not over. My thinking is that the IMSB gets to sit in more oil when the car is not running. Please comment on whether this really matters or is it just fine to be anywhere as long as it is between the min and max marks?
08-14-2018, 12:14 PM
#3
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For me, check stone cold in the morning (and no...not every morning). I keep my level to the top mark on the dipstick. More volume is better in my opinion. 142K miles currently. I manually check it about once a week, but during daily operation, I just wait for the oil level to show on the cluster making sure there is oil, then start and I'm off. I would not over-think this too much.
08-14-2018, 12:17 PM
#4
Instructor
Thread Starter
08-14-2018, 12:25 PM
#5
Former Vendor
The optimum oil level has proven to be in the middle of the indicator. We try to keep our engines between the arrows of the electronic indicator, and the same on the cars with a dipstick. Running near the top, or at the top has proven to adversely impact the health of the AOS, and increases oil consumption. We are seeing cars with secondary air faults from high oil levels as well, its 993 all over again.
Running n the center of the indicator ensures that you aren’t running too low, or too high, and you’ll never have to worry about over- filling if this is done. Only add oil when the indicator is at the very bottom, (after the car has sat overnight on a level surface!) then add 1/2 of 1 Qt and you’ll be right back to the center again.
Running n the center of the indicator ensures that you aren’t running too low, or too high, and you’ll never have to worry about over- filling if this is done. Only add oil when the indicator is at the very bottom, (after the car has sat overnight on a level surface!) then add 1/2 of 1 Qt and you’ll be right back to the center again.
08-14-2018, 12:29 PM
#6
Instructor
Thread Starter
I also noticed that these cars don't like to be parked on a sideways tilt. Usually results in some smoking at startup and one time my car actually through a P1325. The fault went away on its own and I really can't confirm that the fault was a result of a sideways tilted parking event. Just happened to be at the same time. Possible that having oil at mid level or just above the add mark would also be helpful when you can't avoid parking at a slight sideways tilt.
Last edited by USNA1970; 08-14-2018 at 12:30 PM. Reason: spelling
08-14-2018, 12:30 PM
#7
Rennlist Member
Middle mark is maybe a quart low? Not sure getting to op temp would increase volume that much to show an overfill. Anyway, I run at full (measured cold as documented) in hot Texas weather mostly between 3K and 4K and I've not experienced any oil consumption. I change oil every 6 months (about 3,000 miles) and have never had to top off. 2004 40AE with IMS Solution.
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08-14-2018, 12:32 PM
#8
Instructor
Thread Starter
I need to add a quart every 1400 miles. I have been running my oil very close to the top. I may try running it a little lower and see if my consumption changes at all. Would be an interesting experiment.
08-14-2018, 12:35 PM
#9
Former Vendor
Middle mark is maybe a quart low? Not sure getting to op temp would increase volume that much to show an overfill. Anyway, I run at full (measured cold as documented) in hot Texas weather mostly between 3K and 4K and I've not experienced any oil consumption. I change oil every 6 months (about 3,000 miles) and have never had to top off. 2004 40AE with IMS Solution.
Yes, if you believe that putting the oil level at tip top is best, you can expect short drives and parking unlevel will create more start up smoke. We’ve recently had to shoot an in-depth video about this for our engine purchasers. It’s a constant fight to make them understand that to us, the middle of the indicator is “full”. The only time we use the top of the indicator is when doing an oil consumption study.
08-14-2018, 12:39 PM
#10
Instructor
Thread Starter
No! The engine is not Low on oil until the indicator is all the way at the bottom, and flashing! The entire range of the indicator is the safe operating range.
Yes, if you believe that putting the oil level at tip top is best, you can expect short drives and parking unlevel will create more start up smoke. We’ve recently had to shoot an in-depth video about this for our engine purchasers. It’s a constant fight to make them understand that to us, the middle of the indicator is “full”. The only time we use the top of the indicator is when doing an oil consumption study.
08-14-2018, 01:06 PM
#12
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Well, stone cold in the morning is probably relative to where you live. Here, most mornings are high 80's to 90, so I figure the engine is already half way to operating temperature. So the oil temperature is going to also be half way to operating temperature. The warm oil drains back into the sump overnight, I check it on the dipstick, and then during my daily runs, the oil level gauge consistently shows one to two bars below the max line. So I'm not overfilling and have no smoke or AOS problems, and my TB is clean as a whistle. Just my method of operating the car, which given my mileage, seems to be right enough. Don't get me started on the Mini Cooper...check oil at least once a week and always keep it on the full line because it eats oil and only holds a little over 4 quarts, so any drop in level is significant.
08-14-2018, 01:11 PM
#13
Former Vendor
We now find it necessry to replace the electronic senders in the engines when we carry out reconstruction. A few years ago we had several of these fail, and they always show abnormally low oil readings when that happened. One owner over filled the engine by over a quart due to this. This resulted in a failed (new) AOS and other damage.
@USNA1970,
You should note the differences of the oil level being ran at the center of the indicator within a couple thousand miles. In many instances running with the lesser level will decrease oil consumption by 50%.
Remember, anything that makes the engine “happier” is what needs to be done. It doesn’t matter what the owner’s manual said, all of that was written before these cars were utilized in practical application. Keep it happy.
08-14-2018, 01:19 PM
#14
Rennlist Member
