Oil Level (and gage) in 993
12-30-2009, 09:21 PM
#1
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Oil Level (and gage) in 993
Winter time in the Pacific Nortwest (typical daytime temp. of about 40 F). I find even with extended driving (more than 15 minutes), my oil temperature never reaches the second mark on the oil temperature gage (the first mark is just above the "cold" bottom ("at rest") mark). This is the right hand part of the left most gage.
So the oil level gage (just left of the tach) never moves much off the bottom peg. When I check the dipstick (engine warm, running on level surface) it registers between the upper and lower marks.
On the days when temp. is above 50 F, and I've spent time in traffic idling - the oil temp. gage will move above the second mark (between the second and third mark). When this happens, the oil level gage does work and it comes up above the "red" mark at the bottom.
My question is do others experience the same? In summer, when the engine really gets warm - the oil level gage will go way up above the red mark. Often the temp. gage will be up to (and occasionally above) the second mark.
It would appear to this mechanical engineer that the expansion of 11 or so quarts of oil is significant (as it registers on the oil level gage) when it gets "really hot". But funny, the dipstick does not appear to have such extreme variation between "warm/hot" and "really hot".
So the oil level gage (just left of the tach) never moves much off the bottom peg. When I check the dipstick (engine warm, running on level surface) it registers between the upper and lower marks.
On the days when temp. is above 50 F, and I've spent time in traffic idling - the oil temp. gage will move above the second mark (between the second and third mark). When this happens, the oil level gage does work and it comes up above the "red" mark at the bottom.
My question is do others experience the same? In summer, when the engine really gets warm - the oil level gage will go way up above the red mark. Often the temp. gage will be up to (and occasionally above) the second mark.
It would appear to this mechanical engineer that the expansion of 11 or so quarts of oil is significant (as it registers on the oil level gage) when it gets "really hot". But funny, the dipstick does not appear to have such extreme variation between "warm/hot" and "really hot".
12-30-2009, 09:56 PM
#2
What you're seeing is normal, IMO. Here's my previous blah-blah-blah (slightly edited, from back in March) on this topic. Sorry for the excessive ~wind~~~ I just think it's a very interesting.
More recent posts:
I did a bunch of reading a few days ago after the oil volume gauge stopped registering yet the dipstick range was still fine on my car. I discovered:
-Each car is different, and has it's own "sweet spot" in regard to being "full" of oil
-The dipstick range shows ~1.8qts, the volume gauge shows ~1qt
-The sender unit can be adjusted so that the gauge is more accurate for your particular car and operating environment (good pics of the assemblies are here in the forum, just search, look for a recent thread by "shamrock")
-Do not overfill. If anything, underfill slightly until you understand your car (by experimentation, observation and documentation)
-Per the manual if you do a lot of short trips and then suddenly do a long highway trip (or track day!) your consumption will *seem* to go up measurably due to diluting ingredients evaporating out of the oil
-It's A LOT easier to read the dipstick 2-3000 miles after an oil change. New oil w/ the 993 dipstick is a tough read. Daylight helps, but it's quite tricky. Look for a little bit of bubbling to indicate the actual level. Marking the dipstick with gradations using a triangle file has helped some with this too. Others blot the dipstick with a layer of paper towel to better *see* the level, etc. Or you can just wipe/pull/wipe/pull the dipstick a bunch of times until you're sure. (lol.) For me, it's pull/wipe/pull+++ and the bubbles.
Check the oil level (by gauge or dipstick) only after the car is sufficiently warm (20-30 minutes of driving) and only on level ground and only after idling for 3 minutes or more.
With my car after about 3 minutes of idling (after being sufficiently warmed up, first,) at the current oil level I see the temp gauge at operating temp (8:00 o'clock) and the volume gauge pretty much mirrors it at ~4:00 o'clock. On the dipstick this registered at about 2/3rds.
(You will know the car is at operating temp when you see the temp gauge hit the 8:00 o'clock mark and then drop a bit as the thermostat opens for the first time of that drive. In my case right now the weather is about 45* or so, and when the fan kicks in the temp gauge immediately drops 2-3 needle widths, actually below the operating temp mark for a bit.)
To test further I let the car idle for 15+ minutes (after being sufficiently warmed up, first.) The temp gauge went to ~9:30, the highest I have yet seen it under any conditions. (I had never seen it above 9:00 prior to this.) At that point the volume gauge mirrored this at ~2:30. On the dipstick this registered at 4/5ths to 5/6ths.
As temps go up, so does volume. This direct correlation between temp and volume is shown by the two gauge needles mirroring each other, at least at the particular oil level I am at, and on my car. And this is verifiable on the dipstick as well.
-Each car is different, and has it's own "sweet spot" in regard to being "full" of oil
-The dipstick range shows ~1.8qts, the volume gauge shows ~1qt
-The sender unit can be adjusted so that the gauge is more accurate for your particular car and operating environment (good pics of the assemblies are here in the forum, just search, look for a recent thread by "shamrock")
-Do not overfill. If anything, underfill slightly until you understand your car (by experimentation, observation and documentation)
-Per the manual if you do a lot of short trips and then suddenly do a long highway trip (or track day!) your consumption will *seem* to go up measurably due to diluting ingredients evaporating out of the oil
-It's A LOT easier to read the dipstick 2-3000 miles after an oil change. New oil w/ the 993 dipstick is a tough read. Daylight helps, but it's quite tricky. Look for a little bit of bubbling to indicate the actual level. Marking the dipstick with gradations using a triangle file has helped some with this too. Others blot the dipstick with a layer of paper towel to better *see* the level, etc. Or you can just wipe/pull/wipe/pull the dipstick a bunch of times until you're sure. (lol.) For me, it's pull/wipe/pull+++ and the bubbles.
Check the oil level (by gauge or dipstick) only after the car is sufficiently warm (20-30 minutes of driving) and only on level ground and only after idling for 3 minutes or more.
With my car after about 3 minutes of idling (after being sufficiently warmed up, first,) at the current oil level I see the temp gauge at operating temp (8:00 o'clock) and the volume gauge pretty much mirrors it at ~4:00 o'clock. On the dipstick this registered at about 2/3rds.
(You will know the car is at operating temp when you see the temp gauge hit the 8:00 o'clock mark and then drop a bit as the thermostat opens for the first time of that drive. In my case right now the weather is about 45* or so, and when the fan kicks in the temp gauge immediately drops 2-3 needle widths, actually below the operating temp mark for a bit.)
To test further I let the car idle for 15+ minutes (after being sufficiently warmed up, first.) The temp gauge went to ~9:30, the highest I have yet seen it under any conditions. (I had never seen it above 9:00 prior to this.) At that point the volume gauge mirrored this at ~2:30. On the dipstick this registered at 4/5ths to 5/6ths.
As temps go up, so does volume. This direct correlation between temp and volume is shown by the two gauge needles mirroring each other, at least at the particular oil level I am at, and on my car. And this is verifiable on the dipstick as well.
... Get it fully up to temp (as far as it will go while driving, anyway,) and then let it sit for a while. If you let it sit and idle for 8-10-12 minutes the temps will rise to the point where the thermostat should open.
It's been hovering around freezing here and my car's thermostat opens after 15-20 minutes of normal driving (at around 200F.)
It's been hovering around freezing here and my car's thermostat opens after 15-20 minutes of normal driving (at around 200F.)
12-30-2009, 10:29 PM
#3
Rennlist Member
All of the above is good stuff from MONGRELCAT and others. Basically, just trust your dipstick and common sense. If you had oil the last time you checked, then you probably have oil now. Just check the dipstick at the gas station when you fill up. The gauge is really a distraction.
12-31-2009, 12:33 AM
#4
I've had the flu for the last two days and was feeling stir-crazy, + I needed stuff to make soup....
0:00 - cold, stopped
0:00 - started, idling
0:07 - parked, idled ~1 minute
0:15 - underway, thermostat has already opened (i missed that shot)
0:20 - parked, idled ~2minutes
1:00 - parked back at home, idled 1 minute, level gauge shows the natural "full" point for my car
here's the point at which the thermostat opens, right around 12-15 minutes into a drive at the current 40F around here.
... and 10 seconds after that, at what I would consider highway operating temps
bonus "nineninethree christmas tree" shot
0:00 - cold, stopped
0:00 - started, idling
0:07 - parked, idled ~1 minute
0:15 - underway, thermostat has already opened (i missed that shot)
0:20 - parked, idled ~2minutes
1:00 - parked back at home, idled 1 minute, level gauge shows the natural "full" point for my car
here's the point at which the thermostat opens, right around 12-15 minutes into a drive at the current 40F around here.
... and 10 seconds after that, at what I would consider highway operating temps
bonus "nineninethree christmas tree" shot
12-31-2009, 01:15 AM
#5
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^^^That's why I love this place. People like Jason taking the time and effort to show what they mean via long description and pics. Good man!
As others have said, find your particular car's "sweet spot" on the stick and live by it. The oil level gauge is borderline useless in my 95 (only registers on WARM summer days with oil near the top of the stick and oil temp above the second/8'oclock mark) and the one in my 97 is actually quite useful when the outside temp is above freezing.
As others have said, find your particular car's "sweet spot" on the stick and live by it. The oil level gauge is borderline useless in my 95 (only registers on WARM summer days with oil near the top of the stick and oil temp above the second/8'oclock mark) and the one in my 97 is actually quite useful when the outside temp is above freezing.
12-31-2009, 01:31 AM
#6
^^^That's why I love this place. People like Jason taking the time and effort to show what they mean via long description and pics. Good man!
As others have said, find your particular car's "sweet spot" on the stick and live by it. The oil level gauge is borderline useless in my 95 (only registers on WARM summer days with oil near the top of the stick and oil temp above the second/8'oclock mark) and the one in my 97 is actually quite useful when the outside temp is above freezing.
As others have said, find your particular car's "sweet spot" on the stick and live by it. The oil level gauge is borderline useless in my 95 (only registers on WARM summer days with oil near the top of the stick and oil temp above the second/8'oclock mark) and the one in my 97 is actually quite useful when the outside temp is above freezing.
As for the useless gauge in the '95, you got beer -- dontcha?https://rennlist.com/forums/993-foru...vel-gauge.html
Yes, It's a bit cumbersome and may require a few iterations but you can get it so when is 1/2 on the dip stick is exactly 1/2 on the tank.
It's just like adjusting the water tank float in your bathroom toilet...
Try this.
1) Mark where the oil is currently at your gauge after warmed up engine
2) Let car/oil cool down
3) Beer Brake
4) Remove the rear right wheel splash guard to expose oil tank. You will see 6 bolts (part # 4 on diagram) holding the sensor/float in the tank (part #5 in diagram)
5) Make sure that your oil level is low enough so when you remove this oil won't spill out. You can remove some from the tank using a turkey baster to suction from the top.
6) Beer Brake
7) Remove oil level float from tank - be careful not to brake gasket #3, or may be a good idea to replace with a new one while you are in there as these tend to sweat somewhat.
8) Bend down slightly wire holding the tank to the sensor if your reading on the gague is always low, or bend up if the reading is always high
9) Re-assemble float/sensor back in tank
9) put back oil that was removed
10) heat up oil and check measurements comparing reading on dipstick to reading on gauge
11) Beer brake
12) Repeat as needed until either a) accurate readings are accomplished or b) you are fully drunk!
13) And finally, replace rear right wheel splash guard.
Have fun!
It's just like adjusting the water tank float in your bathroom toilet...
Try this.
1) Mark where the oil is currently at your gauge after warmed up engine
2) Let car/oil cool down
3) Beer Brake
4) Remove the rear right wheel splash guard to expose oil tank. You will see 6 bolts (part # 4 on diagram) holding the sensor/float in the tank (part #5 in diagram)
5) Make sure that your oil level is low enough so when you remove this oil won't spill out. You can remove some from the tank using a turkey baster to suction from the top.
6) Beer Brake
7) Remove oil level float from tank - be careful not to brake gasket #3, or may be a good idea to replace with a new one while you are in there as these tend to sweat somewhat.
8) Bend down slightly wire holding the tank to the sensor if your reading on the gague is always low, or bend up if the reading is always high
9) Re-assemble float/sensor back in tank
9) put back oil that was removed
10) heat up oil and check measurements comparing reading on dipstick to reading on gauge
11) Beer brake
12) Repeat as needed until either a) accurate readings are accomplished or b) you are fully drunk!
13) And finally, replace rear right wheel splash guard.
Have fun!
If you look inside your oil tank you'll see that the dipstick is located directly next to the oil level sensor. The stick enters the tank at an angle and the sensor is also mounted at an angle.
As the temperature of oil increases so does the volume. At ~194F/90C the difference between the empty and full marks on the dipstick and your dashboard gauge should match the level difference listed on the engine compartment sticker (someone (Adrian?) mentioned the sticker was wrong in the 964, not sure if that also applies to the 993). So if the oil is at ambient 60F the level would read lower than expected and if the temperature was at 250F it would read higher.
If you look at the sensor itself there is not much to it, basically a potentiometer with a resistor track?
As the temperature of oil increases so does the volume. At ~194F/90C the difference between the empty and full marks on the dipstick and your dashboard gauge should match the level difference listed on the engine compartment sticker (someone (Adrian?) mentioned the sticker was wrong in the 964, not sure if that also applies to the 993). So if the oil is at ambient 60F the level would read lower than expected and if the temperature was at 250F it would read higher.
If you look at the sensor itself there is not much to it, basically a potentiometer with a resistor track?
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01-03-2010, 04:28 PM
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Mongrelcat,
Thanks for this description, car is new to me, temperature is 5 degrees and I saw that my gauge was not changing, checked oil via dipstick, in middle, started to worry ( a little), then did a search and came upon this detailed answer. Now I can relax until the next question thanks to your post and pictures
Wheeze
Thanks for this description, car is new to me, temperature is 5 degrees and I saw that my gauge was not changing, checked oil via dipstick, in middle, started to worry ( a little), then did a search and came upon this detailed answer. Now I can relax until the next question thanks to your post and pictures
Wheeze
01-03-2010, 04:52 PM
#10
Nordschleife Master
Nice work, Jason. I haven't done this DIY, but it looks like it works pretty well. I suspect if you calibrated it for full, it might not be accurate at other levels. When Don's in Campbell did my 90K service at 88,500 miles, after the oil change the oil read full on the dipstick when warm and the gauge red full as well. Double checked with Don on capacities and he said all is correct. I rechecked at 89,500 and the dipstick read 3/4 up the twisty limits and gauge was 3/4 up. I now have 90,500 miles on the car and the oil on the dipstick is just a tad over halfway up the twisty limits on the stick and the gauge after driving on the freeway and left to idle for a minute or two is just above the red at the bottom, so it looks like from halfway down the dipstick, the gauge is off quite a bit.
02-28-2013, 01:09 PM
#11
Rennlist Member
I do not think that the difference in readings is due solely to the change in volume of the oil. The big change is due to the oil thermostat opening and dumping oil into the tank.
Thanks for the pics of the sensor mongrel. I need to check the resistance of my sensor when I change oil next week as I have adjusted mine twice, and after a couple of months, it returns to reading low.
Thanks for the pics of the sensor mongrel. I need to check the resistance of my sensor when I change oil next week as I have adjusted mine twice, and after a couple of months, it returns to reading low.
03-01-2013, 08:00 AM
#12
button queen
WHAT a cool thread!! Personally I find that the gage is accurate ONLY at full operating temp and I don't get concerned at lower temps....if in doubt I go to the dip stick.
As others have mentioned, the oil is generaly so clean even reading the dip stick is a challenge.
As others have mentioned, the oil is generaly so clean even reading the dip stick is a challenge.
05-23-2014, 02:48 PM
#13
AutoX
I've had the flu for the last two days and was feeling stir-crazy, + I needed stuff to make soup....
0:00 - cold, stopped
0:00 - started, idling
0:07 - parked, idled ~1 minute
0:15 - underway, thermostat has already opened (i missed that shot)
0:20 - parked, idled ~2minutes
1:00 - parked back at home, idled 1 minute, level gauge shows the natural "full" point for my car
here's the point at which the thermostat opens, right around 12-15 minutes into a drive at the current 40F around here.
... and 10 seconds after that, at what I would consider highway operating temps
bonus "nineninethree christmas tree" shot
0:00 - cold, stopped
0:00 - started, idling
0:07 - parked, idled ~1 minute
0:15 - underway, thermostat has already opened (i missed that shot)
0:20 - parked, idled ~2minutes
1:00 - parked back at home, idled 1 minute, level gauge shows the natural "full" point for my car
here's the point at which the thermostat opens, right around 12-15 minutes into a drive at the current 40F around here.
... and 10 seconds after that, at what I would consider highway operating temps
bonus "nineninethree christmas tree" shot
05-23-2014, 03:42 PM
#14
Rennlist Member
I just keep it simple and never even check the dipstick. I keep enough oil in the car to tickle the oil level gauge past the orange zone. No more than that. If after a long drive the temp is hot and the needle hasn't moved at all, I know I should add 1/4 to 1/2 a quart. Done. It is OK to run a little light but definitely don't overfill. There's a lot of oil in the system and I have found after my wrench changes my oil, it is topped off to spec and the top 1/4 of oil burns off fairly quickly.
05-31-2014, 12:11 PM
#15
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