Weird oil issue

[BBShriver]

Ok, recently I noticed my oil reserve gauge was staying pretty low. Usually at idle/no load it shows full, with acceleration it will drop down about half... hard aceleration may go down near empty... but it was pretty low at idle, so I check the dipstick... nothing... add a quart, nothing, 2 quarts nothing, 3 quarts.. nothing.

At this point I'm thinkin something is up, and 3 quarts should be plenty for a 2.4L even if it was bone dry, and go for a drive... doesn't take too long before I'm getting massive amounts of oil smoke, and I check under the "hood" and sure enough there's oil more or less everywhere. Dipstick still shows nothing.

So..
A) Why is the dipstick showing empty???
B) on dry sump, why does overfilling cause oil to go everywhere?? I didn't figure overfilling to be too much of a problem on the dry sump system.

And my jeep broke today so now the Porsche is my daily driver until the jeep is back again... I have a fire extinguisher just in case things get ugly but I think it'll just burn off with a bit of time..

[bell]

you know to check the oil with the engine up to temp and running right?
the guage on the dash will fluctuate, and only "works" (meaning gives a somewhat accurate reading) when the car is level and not moving.

[Rot 911]

like bell said you check your oil level with the engine up to operating temperature on flat ground and the engine idling. You have way overfilled your oil tank. You need to get that oil out of there or you will be smoking for weeks.

[BBShriver]

I was aware that the oil gauge is a "dynamic" measurement. Did not know that it had to be running for dipstick measurement though. That's kind of annoying, but now I know.

Tonight when I fired it up, the oil gauge (just sitting in my garage) sits just below max, and when I'd rev it would dip down a bit, so I'm thinking the majority of the overfill is evacuated (to all over everything else).

[tcar]

Originally Posted by BBShriver

And my jeep broke today so now the Porsche is my daily driver until the jeep is back again... I have a fire extinguisher just in case things get ugly but I think it'll just burn off with a bit of time..

No, it won't. It's a DRY SUMP system. No oil pan.

You need to drain 3-4 quarts out before you drive it again.

It was at the correct level before you did this.

Do you have an owner's manual? A Bentley? Do a search here before you do something like this again, at least.

To Check:
Operating temperature (needle at 8:00 position). On LEVEL ground. and,
RUNNING at IDLE (about 950rpm). Let it run like this for 2-3 minutes.

Then check the dipstick. Should be about 1/2 to 2/3 way between the marks.

Don't rely strictly on the oil level gauge on the dash.

[BBShriver]

Too late for that, as it is right now my ONLY mode of daily transportation. I added the oil Saturday. I added oil based on the fact that the oil gauge went from showing full at idle/no load, to showing empty at idle no-load. After adding the 3 qts It showed full under all conditions (idle/load/accel etc). Now it is back to acting normal (full at idle/no load, goes down with aceleration to half-1/4.

But... there is just oil everywhere... even the far side of the engine bay.
However, we are experiencing torrential downpours today, so maybe some if it will get washed off in the rain?

As far as checking the oil at "operating tempurature". How long would you say it takes to get to operating tempurature? This is the first time in quite a while we have experienced weather above freezing in quite some time, and the last several times I've driven it have been in the 10-15F range, and even after around 20 min driving (drive from work to home) the temp gauge had not yet started to move, and engine was still running as cold. In the warmer weather (50F+) I have noted tem seems to settle around 180, and it runs smooth as can be.

I have been trying to acquire a owners manual for some time. Bentley's only cover 74+ and this is a 73. I only have Haynes, which is near useless.
It is my first go with a dry sump though, so that's part of the confusion... wet sump checking oil when it's running is no good since in my jeep I have to wait ~10 min for all the oil to drain back into the pan before it checks accurately.

I suppose I'll have to dig up some more wheel chocks as since I installed the Hargett shifter my parking brake doesn't have enough travel to work, and I don't have anywhere level enough to park it (even my garage floor is sloped, as around here garages are designed to drain water out).

Part of my confusion was last time I had to add oil (again based on gauge going real low at idle), I added 2 qts (all I had available at the time), and the dipstick DID show a tiny little bit... and the gauge still showed a little low, though MUCH better than E. Now, dipstick is absolutely bone dry, and based on previous experience it seemed it should at least show. I guess the last time was just a freak incident.

Oddly, my uncle who worked for Porsche in 73 was under the impression that the oil tank was added because VW/Porsche burned so much oil that they needed a reserve tank. I thought that was a little funny. My dad who also worked at a Porsche dealer in the late 60's (and the last one to change the oil) also did not seem aware of checking the oil with the engine running. So anyway, lesson learned, and I'll know how to check it next time. Guess it's good to be learning this kind of stuff BEFORE we rebuild the engine, while it's still a daily driver/beater. Maybe the oil coated engine bay will help stave off the rust propogation

Originally Posted by tcar

No, it won't. It's a DRY SUMP system. No oil pan.

You need to drain 3-4 quarts out before you drive it again.

It was at the correct level before you did this.

Do you have an owner's manual? A Bentley? Do a search here before you do something like this again, at least.

To Check:
Operating temperature (needle at 8:00 position). On LEVEL ground. and,
RUNNING at IDLE (about 950rpm). Let it run like this for 2-3 minutes.

Then check the dipstick. Should be about 1/2 to 2/3 way between the marks.

Don't rely strictly on the oil level gauge on the dash.

[911K]

The oil temperature has to be at least 180 degrees for the thermostat to open. Until it opens the majority of the oil is in the engine not the tank. This is why you have to follow the procedure of engine up to operating temperature and idling on level ground for a couple of minutes to get the correct oil level on the dipstick.

[tcar]

Till it gets to about 8:00 on the oil temp gauge.

Will take longer on a cold day.

[chris.817]

The lines on the dip stick represent a volume of about 1.8 qts. I look at it as 2 qts and judge it as 0, 1/4, 1/2, 3/4 and 1. I check it often, warm and level (VERY important), usually when returning home unless I'm traveling somewhere. If it's not warm, don't bother. You'll add unnecessarily.

I like it at "1/2" and add 1/2 qt when it reaches "1/4" as described above. No smoke, no leaking, and I never second guess where my oil level or consumption is at. I had issues and now religiously keep a log with Date, Mileage, Level (as described above but I use tenths to keep better track). Again, I add 1/2qt at 25% full and I'm back to 50%.

I've changes units here a cou;ple of times, btu I hope that's clear. Helps my peace of mind.

[BBShriver]

Thanks for the notes.
I drove it for almost an hour on saturday, and it never reached 180.. barely came above 120.
As I mentioned it has been COLD here.

[DW SD]

Originally Posted by BBShriver

Thanks for the notes.
I drove it for almost an hour on saturday, and it never reached 180.. barely came above 120.
As I mentioned it has been COLD here.

sounds like you have a thermostat which is staying open. Do you have only the factory engine oil cooler and / or the body mounted cooler, too?

Doug

[chris.817]

Drive it a bit harder... maintain 3k rpm and see if that helps.

[BBShriver]

It is a 73T (CIS version), and as such has no oil cooler that I'm aware of.
During warmer months (well even January when it was above 30 here) it got up to 180 no problem... it's just in the sub-freezing temps it's been staying cold. Specifically when it's less than 20F

[Formerly Steve Wilkinson]

If nothing else, you need to understand that the oil-level gauge is virtually meaningless while you're driving. the only time it will indicate anything that has any meaning is if you come to a long stoplight, on a level road, with the car at operating temperature. After a minute at idle waiting for the light to change, the level needle should be steady somewhere between halfway up thge gauge and near the top. Any other time, all the gauge is showing you is that oil is rushing into and out of the tank, depending on what the state of the car and engine speed are. the needle will often be at the bottom of the gauge.

And you're right, it is "odd" that your uncle worked for Porsche, although that's not what you meant. He of all people should know that the oil, and the tank, are there because Porsche engines are oil-cooled. (To a similar extent they're air-cooled, but the oil is what carries a lot of the heat out of the engine.) The tank has nothing to do with how much oil a Porsche burns or requires for lubrication, it's essentially a coolant tank.

[BBShriver]

Out of curiosity, Where is the thermostat in the oil system? This is my first air-cooled, dry sump system so I'm still not quite sure how everything works..

[dshepp806]

Forget the gauge and trust the dipstick according to the instructions given here...better get that unneccesary oil OUT of there, too...........

Best,

[BBShriver]

Correction, uncle and dad both worked for Porsche *dealers* in the service dept. Dad was around in the mid 60's (65-66), and uncle in early 70's.

When I said the oil guage was around the "E" that included sitting at idle, not moving. Now it is back to "normal" being full at idle, dipping down around E under heavy load. My Jeep has been in the shop accumulated several weeks this year, so the Porsche has been my daily transport maybe 4-5 weeks so far. I'm pretty familiar with the dynamic measure displayed by the gauge. It just concerned me when it NEVER came above E...

I will check the dipstick when I get home tonight. It has warmed up a bit today, so maybe it will reach temp.

[tonythetarga]

Originally Posted by BBShriver

Out of curiosity, Where is the thermostat in the oil system? This is my first air-cooled, dry sump system so I'm still not quite sure how everything works..

Check out this tech article (in fact, you should check out all of them as there are plenty of good tips there).

http://www.pelicanparts.com/techarticles/911_oil_leaks/911_oil_leaks.htm

The thermostat is at the back of the engine near the firewall. Actually it is the front of the engine, but the picture in the article should show you exactly. There is also a parts catalogue here on PP and you can get another view of the location. Not sure if 'tapping' the thermostat will work for this location to see if it closes until it reaches temp and opens to allow circulation through the cooler.

The reason the 911's have more oil is not because they leak so much, but because they are both air and oil cooled and would need more than the 4 or 5 qts water cooled cars use. Oil leaks should not be acceptable. I've heard that all my life about Harleys and Brit bikes as well. They only leak if you allow them to.

[BBShriver]

My 911 does leak excessively, but that's another story... It's due for a rebuild for a number of reasons.
Our 1955 Jag with a fully rebuilt (~$10k cost) engine also leaks considerably..
99 Ferrari also leaks.

Before the Porsche, my project was the Jag, and general rule of thumb according to the other owners was if it's not actively leaking oil STOP... that means there is no oil left..

But uncle was not talking about leaking, he was talking about burning oil, and implied that you needed to "top off" your oil more or less every time you fill up the gas tank.... and that was with brand-new off the showroom cars. I have not noticed any oil burning save a little at start up, so no idea what he was talking about.

[rgrimm]

If you drive it for 20 minutes or so, it should give you at least a close idea of the amount of oil in the engine.

My 84 oil gauge will never register as full, unless it's overfilled--yup, that's how I know!). If you find it's slightly high, you can get a little out without taking the plug out and risk taking it ALL out. I used a a 4-foot, half-inch plastic tube and siphoned it out the filler neck. Even managed not to inhale any