How much oil??

[Kryptonite]

Hi Guy's, from what is see in the Service manuals my '73.5T needs approx 9 litres of oil.
I've got in 11 litres and still not showing on the stick.
I know to check final level when warm and at idle but should it not show some on the dipstick when not running??
I did not get to run this car before the restoration.
The motor is 2.4 CIS with no oil cooler,original oil tank I think.
Maybe the wrong dipstick??
Maybe larger capacity because of no oil cooler ??
Thanks ,
Manfred.

[Miguel Antonett]

Crank it up and let it warm up, then you measure the oil level. 9 quarts do expand a lot after reaching operating temps. My 930 doesn't indicate a thing being cold. You definitely DON'T want to overfill it.

[Dantilla]

11 litres is plenty to start your engine.

Some of your oil is sitting in the engine sump. When you start, the oil wil be pumped back into the tank where it will show up on the dipstick.

[Wil Ferch]

Think about this..... really.....we have a "Dry-sump" engine.

The "tank" is alongside the engine....it is NOT part of the engine like most cars that have a "wet sump"....where it is located on the bottom of the engine. NO...the "alongside" tank will NOT show level when the engine is OFF.

Just helping you to visualize what you have...and what's going on.

- Wil

[Kryptonite]

Well.............. I'm thinking that with11 litres of oil there is none showing on the dipstick even when running.
Do i need to wait for engine to warm up before it will show??
Just don't want to F.. anything up at this stage.
Thanks,
Manfred.

[Wil Ferch]

If you did a search..or if you have an owners manual....you will see you NEED three things for proper oil level checks.

- car on level ground
- engine at 800-900 idle speed.
- engine oil up to 190 degF temp ( usually at around the 8 o'clock mark on the various oil temp gauges. The faces changed over the years).

No...not *any two* of these......ALL THREE .........

- Wil

[Quicksilver]

It is so important to check the oil level hot. The car must be completely warm to get an accurate reading. The oil level will rise as it heats up but not because the oil expands with heat. (It doesn't expand that much.)

As Wil mentioned, you have a "Dry Sump" motor in the 911. That means that there is more then one oil pump in the motor. A dry sump will have one or more pumps that tries to pump ALL of the oil out of the motor. This oil ends up in the external tank. That is why it is called a DRY sump. (pumped dry)

Obviously you can't suck all the oil out of a running motor but as the oil becomes thinner (when the motor is warmed up) it is easier to pump more of the oil out of the crankcase.

--
So make sure that the motor is completely warmed up before checking the oil level and remember that when the engine is off the oil will drain out of the reservoir and back into the engine.

[Paulporsche]

The level won't measure correctly until the engine reaches about 180F. Since your spec calls for 9 and you are sure you have 11 in there, to be safe, I think I would drain some out before I fire it up and get it hot. Then start adding until you get to the correct level, which would be about half way between the 2 marks. BTW an external cooler adds more capacity. And yes, of course, it's always possible you have an incorrect dipstick, but I would try the above procedure first.

[Quicksilver]

Originally posted by Kryptonite
Well.............. I'm thinking that with11 litres of oil there is none showing on the dipstick even when running.
Do i need to wait for engine to warm up before it will show??
Just don't want to F.. anything up at this stage.
Thanks,
Manfred.

If you have put 11 liters in and there isn't any oil on the ground you are fine. If car isn't being driven hard the oil does't slosh around so you have quite a reserve when the car is just sitting there.

Actually I wouldn't put in 11 liters after a change. I would put in 9 or 10 and let it get to temperature before adding more.

BTW - The marks on the dip stick aren't 1 liter or 1 quart apart! I believe it is closer to 1.5 liters.

[Wil Ferch]

Another factoid.....

Cars with front oil coolers have a (filled) system capacity of about 13 qts.....but 3 qts always "stays behind" during change-out...leaving about 9-10 qts for change-out capacity.

When you *do* change out the 9 qts...about 6 should come from the oil tank and 3 from the engine sump...if the car oil was changed warm and the engine was recently run. If , OTOH....you're changing out "cold" like when you're doing a valve adjustment...the values are reversed. About 6 qts comes out of the engine, since it settled down there...and three comes from the tank.

Cars without oil coolers only have about 9-10 qts total system capacity....be careful on refill amounts.

I see these posts all the time...especially when the car gets refilled with too much oil. Why is it so hard ( when doing this) to capture old oil in 1 gallon plastic milk jugs..and measure? Then...quite simply....put in what came out before...no chance of overfilling.

?????

- Wil

[Quicksilver]

Originally posted by Paulporsche
The level won't measure correctly until the engine reaches about 180F. Since your spec calls for 9 and you are sure you have 11 in there, to be safe, I think I would drain some out before I fire it up and get it hot. Then start adding until you get to the correct level, which would be about half way between the 2 marks. BTW an external cooler adds more capacity. And yes, of course, it's always possible you have an incorrect dipstick, but I would try the above procedure first.

I thought the oil change spec on the 3.2 Carrera was 10 quarts. Where did the "9" come from?

[Wil Ferch]

Let's not quibble over 9 vs 10 qts.....try to focus on the *big* picture ( 3 qts stays behind....6 vs 3 out of the tank during change out, etc)...otherwise this thread will follow the 94 vs 96 ft-lbs wheel bolt torque category !!!!



- Wil

PS-- on the original question... I would completely drain...measure what comes out...and start over. Try closer to 7-9 qts on initial fill before you start using 11 for initial fill. I believe your total capacity is around 9.

[Dantilla]

The initial fill for my car (3.2, Elephant lines and cooler) took 15 quarts. If you have just added cooling capacity, the car may take more.

But 11 is plenty to start, warm up, and add as needed. Do not add any more until you check it hot.

[Kryptonite]

Thanks to all for the help.
Tonight I will drain out a couple and try again after a good warm up.
Manfred.

[David E. Clark]

This description of a "dry sump" engine is the best and most concise I've seen. It's from Mike Allen, senior editor for Popular Mechanics magazine.

"Dry-sump engines use one or more engine-driven pumps to scavenge the oil from a similar but smaller sump and deliver it to an external tank near the engine. This tank holds far more oil than the wet sump could, and it allows any air in the oil to bubble to the top before the main oil-pressure pump sends it back into the engine.

A major advantage of a dry sump is that the entire engine can be lower in the car when there's no large oil pan. Another advantage is better control over the oil in hard cornering and braking. The system keeps it from sloshing around and uncovering the pickup, or splashing into the crankshaft and getting aerated. This saves horsepower by letting the crank rotate freely instead of pushing oil around."

[Jgordon]

I usually put 9 in and warm up the car, filling more when it's hot. I usually get to 10, 10.5 total. I wouldn't necessarily drain your tank and start over. Turn the car on when it's on level ground, and when it gets warm, check it with the dipstick. You should be at, or maybe a little above, the top line on the stick. I'd be surprised if this presented a bad/dangerous situation.

[Wil Ferch]

Jgordon:

Sorry.... but wrong on two counts.

1.) your car is an 89, with a front oil cooler and lines....total system capacity is 13 qts and refill capacity is 10. The original poster has a 73.5 and has no front oil cooler. System capacity is 9 qts ( or so).

.....not comparable....

2.) Overfilling is indeed bad...see the many posts on this. It often leads to apparant high oil consumption because the excess, when warmed, goes to the intake tract / air cleaner area and makes a *mess*. Sometimes bad enough that it leaks through the engine tin (gaps) and flows through the engine mounted cooler..as seen from below. Now you think maybe the engine oil cooler is springing a leak..and even if it's cleaned up, you can't clean the small passages between the engine mounted oil cooler very effectively..and now you've got oil that forms a oil/dirt crud in the small spaces where the air flow goes through...

Kryptonite..what will draining a "little" out do for you ? Drain it ALL out...measure. Now you know how much you have. Then, if clean, refill with the same oil ( or use new) and don't go over 9 qts the first time around. Then , check level with all 3 things in-play..and add only if you need to.

Wil

[sig_a]

I recently purchased a 87 Carrera 3.2 w/17000 miles from the original owner. I'd never changed oil in a 911 until yesterday. The owner's manual says oil change is 10.5 quarts. I filled 10 quarts, drove the car about 7 miles and checked the stick which indicated the level was below mid point. I then added another 1/2 quart. The stick now reads just shy of max level. Oil level gauge reads just shy of max at the high end of its range. Are these readings acceptable? And isn't it a good thing to have the oil level near max because of the relationship between oil quantity and engine cooling efficiency?

[dentist90]

sig_a, congrats on your first post!
Your 87 will have an oil cooler up front, plus the engine-mounted oil cooler, and with 12-13 Liters total it will be hard to overheat your oil unless you are racing it on a warm day. Besides, if you are at the point where your engine is cooking your oil 1 extra litre will probably not make enough difference. Keeping oil at max level is fine, but don't overfill unless you really want to see blue smoke. You will notice that the level on your oil tank guage will be low or 0 at startup, and after driving around for 20 minutes will be near the top. Gives you an idea how important it really is to check oil level ONLY when car is fully warmed up.
Pictures of your car would be completely acceptable at this point, too!

[ischmitz]

I agree that oil level needs to be checked at operating temperature. However, with a coefficient of thermal expansion on the order of 0.00032 /deg. F the volume increases only by 4 percent when engine oil warms up from 80 degrees to 200 degrees. This roughly half a quart and hardly visible on the dipstick.

What really happens is that the oil get aerated by the scavenge pump once the engine runs. The air bubbles in the oil tank are what makes the oil level raise on the dipstip.

Ingo