Oil level / Oil Pressure question ('89 964)

[slyaside]

Preface: I'd like to apologize if any of this comes off as "stupid" or seems as if I haven't already done some browsing to find an answer. I'm actually only asking because I don't feel like what I've read so far has given me the answers I was looking for. I've had this 1989 964 for about two weeks and I've realized that all my experience with every other car I've ever owned is mostly useless.

Here goes:

The oil level gauge stays in the red, under very heavy (full) throttle it will occasionally bounce up to the top of the red but never goes into the white.

After a 10 mile drive and subsequent short (1 minute) idle, on level ground with the engine running I'm seeing very little oil on the dipstick. It looks like it's half-full from what I can see on the stick but frankly there's just not much actually ON THE STICK to read. For clarity - there is oil visible on the stick to what I would consider "half" (between the curls and notches) but it's not a coating of oil, just a little bit adhering to the stick here and there, stopping at the midpoint.

The oil temp looks fine, it runs about 1 - 2 bars depending on what I'm doing with the car or what speed I'm at. Since I've heard that low oil levels will cause overheating, I'm thinking that maybe there is more oil in there than I suspect. I've read the horrors of overfilling so I'm hesitant to just start adding oil.

So, after all that - my question is mostly about the dipstick and oil level gauge. I know the gauges are notoriously inaccurate but shouldn't I be seeing more of a coating on the stick?

Also, after buying the car I found a half-empty bottle of 0w-40 up front. I think that's what the previous owner was using, is it possible that super-light synthetic crap is what's causing all the behavior I'm seeing?

Any advice (even just asking me to re-word this into something readable) would be appreciated.

Thanks.

Edit: I removed a portion because it was actually stupid and inaccurate.

[Esel Mann]

I believe, the oil gauge, is like the earlier 911's. It simply measures oil level in the oil reservoir at idle. That is to say, outside of idle, not much ever "builds up" in the oil reservoir and typically reads at red when outside of idle. Oil pressure gauge however does the opposite (a good thing).

As far as that dipstick, I too am still scratching my head on that one. That thing is harder to read than my horoscope. Perhaps it is an inside joke within Porsche. I have never found a definitive answer on the "tea-leaves" reading of the dipstick myself. The earlier 911's didn't have such so I had nothing to compare to. They only have the oil reservoir stick which seemed to coincide well with the oil gauge reading.

What I have seen is (at idle on the 964) is things don't begin to show on that dipstick until the oil gauge reads at~half way. The problem is I believe the oil reservoir of the 964 suffers the same issue as the earlier models. That is, bringing the oil reservoir near "full" can have consequences (oil uptake into the air-intake) so there is some wiggle but not a whole lot.

Hopefully others have encountered similar and can chime in.
Also note, that once I begin adding oil (20W-50 dino) the reading on the stick does become ever slightly more discernible. Not enough for my comfort, and is not repeatable thereafter Until I add more oil of course.

[KNS]

Not a dumb question... The twisty dip-sticks on the 964/993s are more difficult to read than the older 911s. You're reading it correctly - at idle, running and warm. Halfway up the stick is correct. Ignore the oil level gauge any time the car is moving. If you're seeing oil on the dipstick I think you're alright. A bone dry dip stick would be a problem.

0W-40 is not the right oil for the air cooled cars. Not to start an oil debate, but you ought to be using 20W-50 or 15W-50 in warm climates or perhaps a 10W-40 or 5W-40 in cooler climates. A heavier oil may be a little easier to read on the stick.

[slyaside]

Originally Posted by Esel Mann

Oil pressure gauge however does the opposite (a good thing).

That's the only thing that's kept me from changing the oil just to be sure.

Originally Posted by Esel Mann

What I have seen is (at idle on the 964) is things don't begin to show on that dipstick until the oil gauge reads at~half way. The problem is I believe the oil reservoir of the 964 suffers the same issue as the earlier models. That is, bringing the oil reservoir near "full" can have consequences (oil uptake into the air-intake) so there is some wiggle but not a whole lot.

Out of curiosity, with a gauge at nearly half and oil on the stick do you have any idea how much oil was actually in that car? I have not even a guess as to how much oil it would take to move the gauge but from what you're saying it sounds like it might be safe to add a bit at a time and find out. My concern here is that the gauge itself is incorrectly calibrated or just plain broken and the oil in the car is too light to see on the stick.

Originally Posted by Esel Mann

Hopefully others have encountered similar and can chime in. Also note, that once I begin adding oil (20W-50 dino) the reading on the stick does become ever slightly more discernible. Not enough for my comfort, and is not repeatable thereafter Until I add more oil of course.

Genuinely helpful and somewhat re-assuring. Thanks.

Originally Posted by KNS

Not a dumb question... The twisty dip-sticks on the 964/993s are more difficult to read than the older 911s. You're reading it correctly - at idle, running and warm. Halfway up the stick is correct. Ignore the oil level gauge any time the car is moving. If you're seeing oil on the dipstick I think you're alright. A bone dry dip stick would be a problem.

That's one thing I was looking to hear. There IS oil there, it's just hard to see.

Originally Posted by KNS

0W-40 is not the right oil for the air cooled cars. Not to start an oil debate, but you ought to be using 20W-50 or 15W-50 in warm climates or perhaps a 10W-40 or 5W-40 in cooler climates. A heavier oil may be a little easier to read on the stick.

I thought it seemed light, and now I've got myself convinced it's full of the stuff. I'm not really interested in debates myself and appreciate the advice for what it is. I'm in Texas, at any rate, and being unclear on this "cooler climate" thing you speak of I'll go with something heavier when I change it. Should I be concerned enough to do so immediately?

Thank you for the responses, I'd welcome any additional input. At the moment I'm just trying to wrap my head around this wonderful creature and most importantly do no harm until I start to address it's other much more obvious issues.

Every time I start it, I'm a little bit happier I bought it.

[Esel Mann]

Changing the oil? Not sure what you mean. Oil changes are based upon time/mileage. One adds oil periodically to top off as the oil does eventually "escape" by one natural means or another not so natural means.


To your other question, I do not have the books accessible to me at this moment, however I did a quick-n-dirty search, DFINNEGAN posted on Rennlist: "The stick reads 1.75 liters top to bottom and the gauge reads 1.25 liters (+0.3 to -0.2 liters)." That may explain the difference we observe. The gauge being a measure of the reservoir level which being a reservoir can be +/-. That would be in reference to full oil which I believe is something like 12 or so quarts (yep gallons!).

Note that Rennlist is analogous to Pelican Parts. Very knowledgable people. Equally nice too! Only difference is lots of Brits on Rennlist so if you start making Benny Hill or Monty Python references they get it. Here, not so much. Note: never make reference to the Monty Python "Bruce skit", there are Aussies on that forum too (as well as Pelican), they may not have the same humor as Brits

In the end, if you are concerned about how much oil is in there, the above gives you an idea. Between the dipstick and the oil gauge one can keep things within limits. Additionally one can also ascertain whether their oil gauge is "reasonable". If it isn't you can then proceed to narrow down if it is the gauge, wiring, or sensor.

Enjoy it!!!

[slyaside]

Originally Posted by Esel Mann

Changing the oil? Not sure what you mean. Oil changes are based upon time/mileage. One adds oil periodically to top off as the oil does eventually "escape" by one natural means or another not so natural means.

Thanks for the measurements. Regarding changing the oil, I mean it literally - the previous owner had no service records, provided very little real information about the car and the bottle of 0w-40 I found leads me to believe the oil is extremely light. KNS seems to have suggested it's actually entirely wrong for the engine and I'd just as soon empty and refill it with a known quantity and type than start mixing oils.

Thanks again!

[KNS]

If you're due for an oil change then you may as well drain out the 0W-40. If it's relatively fresh, you're probably alright for now as we're heading for cooler weather.

Edit: If you lived in Vermont the 0W-40 may be fine year 'round (although I would use something else...). In Texas I wouldn't keep it in there through summer.

[bri450sl]

If it's a new to you vehicle or you're just unsure of the oil quality/type, why not change it and then have piece of mind knowing its fresh (with your choice of oil type/viscosity) and full?

[si Banker]

What part of Texas are you located in? I have always changed the oil when I get a new car assuming it is a used. car.

I do not think 40 weight oil is correct. I would suggest 20-50. Also I am looking into a additional oil,cooler because of the heat.

You are not able to get a good reading on your oil level until the motor is warmed up. Make sure the car is on level ground and the engine is at idle. I had trouble reading the dipstick It was hard tell if there was any oil on it. I solved the problem by sprinkling a very small amount of flouri on the area where you read the level

Do not worry about the oil Gage and the level will change when you get on it.

[slyaside]

I've replied to this thread already but for some reason I get a message saying my post must be approved by a moderator, so I don't know what's happening there.

I am in Austin and I did just go ahead and change the oil, by my (rough) measurement I only got about 8 quarts out of it so I'm glad I did. I used a 20-50.

Even after the oil change, a short drive, idle and check of the dipstick I can't for the life of me tell what it's saying. The upside is that now I know exactly how much is in there and what kind. The gauge, of course, still says it's empty.

Got my replacement center rear reflector yesterday (the one on the car is completely broken) and the eBay seller had it listed incorrectly, looks like it's for a Turbo instead of a Carrera. You win some and you lose some I guess. To be fair, it was delivered in OEM packaging as promised..

[porterdog]

Hiya! Just did my third change.

Experience has shown that on my car all I want is for the oil level gauge to move off zero. Note well, the oil needs to be hot and a 10 minute drive will NOT get it there. Ideal is around 9 o'clock on the gauge- your thermostat is open and the oil is hot.

Any higher than that (on my car) and I get oil dripping out the split between the intake halves.

This level is just above the bottom notch. Again, on my car, this amount (following a 'full drain' [both bungs but no acrobatics to get all the oil out] and filter change) is approximately 8.6 litres/2.3 gal.

[RSTarga]

The car need to be at least at 180 degrees, at idle before you can check the oil level. That means after oil change add 8 quarts drive for a 30 minutes to get everything flowing and open and then check.

[Newsboy]

The car holds about 13 quarts. 2-3 quarts remain in the oil cooler/piping.So your only replacing around 10 quarts.

[slyaside]

Okay so now I'm thinking I have overfilled. Instead of starting a new thread I'll just ask here and hope for a response. I changed the oil a few days ago and used about 10 1/4 quarts when filling.

Once the engine is fully warm the level gauge is showing "overfull", meaning that if I idle for a long period (several minutes) it will climb above the top white tick. Under any other circumstance it remains well into the red. Dipstick is still completely unhelpful but does not seem to have any oil on it above the "full" notch.

No smoke, idle is still smooth at 8-900 and no evidence of oil spraying (any more than usual) and no other ill effects. Should I try to drain some? The car leaks pretty badly, if it's only overfull by 1/2 quart or so can I just let it escape naturally or is this a panic moment?