Clarification needed on checking oil level...
 

Ok, still a newbie so looking for some clarification....I've read the other posts regarding the proper procedure for checking oil level, but have some questions....

As read;

1. Warm operating temp (at 1st hash mark above bottom mark on temp gauge, i.e. 8:00 on the clock dial)
2. Level ground
3. Engine running

Should read 1/2 way between high and low on stick, level gauge should correspond to 1/2 way mark.

Here's where I need the clarification - this was my experience on the first time round....

During normal operating temp (at 1st hash above bottom, maybe slightly above sometimes), the oil level gauge hops around right at the top of the red mark as a midpoint (even after letting oil settle for a minute or so). The dipstick reads oil on the very low end tip of the stick - I thought the oil was probably low. (oil had just recently been changed by a shop before I bought the car a couple of weeks ago. Also, I have been reading about how the oil level gauges are chronically inaccurate, and thought I would probably need to go through the re-calibration process that I had read about on the board.)

Now, here's what I didn't understand - a couple of days ago, I was looking for a vacuum leak and so was manually operating the throttle from the engine bay. The car was running for 5-10mins or so.

I then sat down in the car and looked at the gauges again - this time, the oil temp gauge was around 9:00 to 9:30 area (just below the 2nd hash mark from the bottom mark) and higher than I've ever seen the oil temp, even after thrashing it about a little). This time, the oil level was reading perfectly in the middle of the gauge, (as I've read it should be....) and furthermore, I re-checked the dipstick at that point and it was reading perfectly in the middle of the high and low marks....

I've seen consistent oil pressure marks with what has been described on the board....at idle around #1, cold and with RPM's up to #5, and normal crusing around #3.

So...questions...
1. Am I mis-understanding how warm or hot the car should be when I check oil?
2. Did the oil cooler thermostat open and change the oil level?
3. If so, how can I tell in the future when it's 'warm enough' to open the thermostat? (what i'm seeing seems like a higher oil temp than has been recommended by others as 'normal operating temps.)
4. Is this difference due to temperature expansion alone?
5. Or, is there something I should be concerned with?

Thanks for the help!!

The oil level on my 84 Carrera fluctuates as well. When I do an oil change, I warm the engine to the first hash mark and the level on the dip stick is around the middle. After a drive, lets say 40 - 50 miles the level on the gauge is very close to the top.
That's always been normal for my car and I've put over 100k miles on it.

I would add 1.5 Leave Car ON, secure E-Brake.

It you want to know for certain get a IR thermometer and and measure the out bound to front cooler oil line in the passenger rear wheel to see where the temps really at, you want 194 degrees.

or

1/8" above first hash mark .

If the needle fluctuates up to red then it may mean two things, too much oil (verify with dip stick) or the Oil Sending Unit is on the Fritz, you can swap or service if the coil is not damaged.

Here is my write up: http://forums.pelicanparts.com/porsche-911-technical-forum/594192-oil-level-sending-unit-how-service-repair-maintain.html

It could also be your dip stick touching the float arm of the OSLU, if you have a bit of resistance when pushing in the stick the you need to bend it in a bit to avoid touching the arm of sending unit.

Bottomline, Revert to OIL DIPSTICK when at 194+ degrees while car is on, wait a few minutes and at level ground. You want to be between high and low mark. IF Your baby iS healthy, she will consume about 1qt per 100 miles per PAG Manual.

Jim

Sounds like you're doing it right. FWIW, the dash gauge can be notoriously inaccurate. When in doubt, trust the dipstick (the one in the engine compartment, not behind the wheel ;)). I think what you're noticing is likely due to thermal expansion. When the car sits stationary, as you did while checking for a vacuum leak, there is less cooling airflow through the engine compartment, which is maybe why it got warmer than you've noticed while you're actually driving the car. I don't know the exact temp at which the thermostat opens to the front mounted cooler, but I'm sure someone with more mechanical knowledge will chime in.

A couple points come to mind to share with you about oil level.
With so much oil in the car it takes considerable time to warm to operating temp. Also the oil level rises quite a bit with the expansion. so make sure it well warmed for the check. I often check mine after returning home after a drive. Just leave it running, pop the engine lid open, and pull the stick. This is a good chance for a visual inspection.
While driving, the guage in the dash fluctuates with the revs, At idle the guage shows a higher level, then while motoring along the needle drops quite a bit, then to rise again at the next stop and idling. The gage comes to be something of an indicator, But the dipstick is the real measure to go by.
I really freaked the first time I checked my oil Right after getting the 911, there seemed to so much oil missing, but no pool under the car. I had a hard time running the engine with such a low oil level to get it up to temp. Kind of counter intuitive.
It is a bit of a learning curve at first, That is the beauty of this forum. There is great helpful knowledge at all stages of the process of becoming one with your 911.
There really no dumb questions here. Tho I suspect some who have felt dumb for not asking when we should have.
Welcome aboard!
Cheers Richard

WOW:eek: maybe you mean 1qt/1000miles

+1 on the 194 degrees. I think the 1st hash on the oil temp gauge is still too cold for an accurate reading. One way to tell if the thermostat has opened (if you don't have an IR thermometer, as DRACO stated) is to very very carefully feel the front oil cooler / lines. They will be hot when the t-stat has opened. The first time I drove my 911 I burnt my hands on the lines after a drive, so be careful :)

Doh! my stupid Monkey Fingers :rolleyes:

EDIT: Approximately 1 Quart per 1000 miles per PAG Manual. Geez I'm glad this ain't an essay exam. :eek:

After my fix, my gauge is accurate when warm. Come to think of it, when cold too because when the gauge falls to low position, it is said it is a quart low. When warm about a quart flows back into the sump.

Think about it fellas, when you can't help yourself and eye ball the gauge at low after a steady run, you jump out to check and fill, how much do you fill? I recall it is almost always 1 quart before I fixed my OSLU/gauge.

Jim:confused:

Yeah, get it WARM, not just to when the needle on the gauge creeps past the bottom line. Another thing is that there is a whole lot of oil in the system. If you run it at the lower part of the dip stick, you won't do any harm. Too much oil isn't good for the engine and tends to run through the intake to make your ride smoky. Or when you check it not warm enough and add some to find out it's now too full...

+1 better less than too full.

Geez, PAG was bunch of HALF EMPTY GLASS kind of guys, eh?

Isn't there 6-7 quarts in the Crank, 2.5-3 in Sump and about a 1 in front cooler?

The owner's manual for my '86 Targa says 1 litre per 1,000 kilometers!

Please disregard my 1qt/1000miles, IT IS NOT IN THE PAG MANUAL or any manual for that matter. My sincere apologies, I must have read it from another Pelican. My fault for not verifying.

Here is what my 85 PAG Manual states:

http://img.photobucket.com/albums/v5...421_172602.jpg

So oil consumption depends on how your baby is used.

Good stuff guys - really appreciate the inputs. I'll give it a good spirited, longer drive to make sure I've got it up to temp and confirm the the oil cooler lines are good and hot.

The irony is not lost on me that for such genius precision in every aspect of this car, there's a good amount of subjectivity in adjusting what may be the most important 'lifeblood'... getting good at it is what makes this a fun journey in ownership, and a good reason I'll never let a Jiffy Lube tech even touch the deck lid release.

Well said sir, well said!

Heh heh. Just wait 'til you start asking about how to jack up the car for an oil change, or which oil to use...

1.) First hash mark at 8 o'clock is too cold..as stated.

2.) The oil level gauge is *not* charactetistically inaccurate.....it shows the comings-and-goings ( level) quite accurately as the rpm's rise and fall. This is commonly mis-stated, don't beleive it. RPM's have to be 800-900-ish....at 1100 (say) it's already too high and will force the level reading down into the red zone.

3.) The dipstick high-to-low range is only about 1.7 qts...on a system that holds 13. Even reading "nothing" might mean you have 8-9 qts in the system....and does not necessatily mean the oil system is empty...the reason most guys overfill.

Agree that 8:00 is too cold, but still should be a point where if you fill to maybe one-third of the way up between the lines on the dipstick, you will be OK. Once the engine is warmer, it will read 1/2 + between the marks, due to the aforementioned expansion.
Excessive idling has been pointed out to me (as it's written in the manual) as "not recommended". Ten minutes would be considered excessive, I'm sure....I always try to rev at idle now and again a bit to increase fan speed for airflow and move oil around. Of course you then have to wait a few more seconds to get a proper oil level reading if that is why you are idling....
But 13 quarts? Is that right? Sounds high according to my early morning, only-2-cups-coffee-thus-far memory. :)

yeap 13 qts, that is in the total system but OEL CHANGE is 10.5 per Bentley SPECs

Yep, went and checked; owner's manual says pretty much the same. Some three quarts or so "hides out" in there when the system is drained! My recall was that from the last case I used for a change, I had over 1.5 quart bottles left, reading at half-way on the 'stick. :cool:

My big thing is to make sure the front oil cooler lines are nice and toasty...then (and only then) do I measure oil level. My '89 always takes 10.5 quarts, every single time. Still, I only put in 9 quarts, at first, then take her out for some spirited driving,..achieving the target temp,..then measure after loading another quart (now, at 10)...then go drive some more (a long one)...then finally top her off to midscale on the stick (! 1/2 quart more). Totals out @ 10.5 quarts on the changeout.

best!

Doyle

i thought i'd dig up an old thread rather than create one - so porsche conundrum #1

i just drove the car back from melbourne to brisbane (a good 1800kms)

checked the oil when i set off, all good. did some kms, next fuel i stopped and cheked the oil with engine at operating temp - chucked in 200ml as it was at half way (difference between high and low is 1.6 litres?)

checked this morning, dipstick still at a similar level so added a little bit too (was thinking about running it up to full but sitting at half way seemed reasonable considering i didn't want to overfill it)

go for a bit of a drive tonight to grab dinner and take pics, get home, check oil and it's not on the $%#%#@ dipstick - engine is at running tempreture, has lots of oil pressure according to the dash, also has oil according to the level gauge - but the dipstick isn't even showing oil. I know not to trust the gauge and rely on the dipstick so that's why i'm a little worried.

no weird noises, no oil pressure warnings, no smell, no tempreture change (going from VW engines that i've seen at engine blows these things all happen)

add around 1 litre, still no oil showing on the dipstick!

i know the full system takes 12 litres with a sportomatic - it has no huge oil leaks i can see (has a tiny drop which may have even been from my other car) - it isn't burning oil or it'd be blowing blue and leave a residue above the exhaust... and i can't really smell burning oil either

at this rate i'm letting it cool off and i'll have another look in the morning and check for oil at the low mark where it should be - anyone got any ideas?

Hey! I just did the same drive Melbourne to Brissy (well Gold Coast).
The only oil level check I trust completely is the dipstick in the morning, prior to starting. All the oil has drained down into the sump. After each fuel stop (had to plan Shell fuel stops to get v - power!) the gauge showed 1/2 full, 1/4 full & 3/4 full??? I ended up adding 200ml one night & next morning it showed overfull on the gauge but the dipstick showed perfectly full (on the mark).
Out of interest what oil do you use? I'm thinking of something thicker than 0W-40 for QLD?

i just sussed it after reading back through this thread

i think i'd measured it before without the oil cooler opening up, so i got it up to the 8 o'clock temp mark (which is where it always sits when warm) and the gauge still read 1/2 full - added a litre and it came up to half way on the dipstick!

it's a penrite oil, i can't remember which one (it's down in the garage - pretty sure it's a 15W-60 HPR something)

you should probably be checking it warm, with the engine running unless it's different for the newer cars, as they're dry sumped and you're checking how much oil is in the whole system, not just drains down into the sump

To be absolutely sure, get a IR hand held temperature gauge to measure the temps behind the right rear wheel. at the outlet hose to the front oil cooler, if the temps are below 90 degree C ( 194 F ), the thermostat will not open all the way and it will give you false oil level readings.

12 litres (12.68 quarts) is WAY TOO MUCH, you will create an over flow once the thermostat opens all the way.

Per Bentley the max oil fill on CHANGE with front oil cooler is 9.94 litres ( 10.5 quarts ) to be safe I put only 9.70 litres (10.25 quarts) then top off onliy after it hits 90C+, and running , never ever before.

Hope this helps,

Jim

Reviving this thread to ask a question (based on the assumption that there are no stupid questions...)

The oil level on my dipstick differs. The front side (facing the engine) shows very low oil level. The back side (facing the right rear fender) shows oil level about 1/3 of the way between the empty and full marks. Reading taken at standard operating temp, level ground.

Should I add oil or am I OK?

TIA