waybrig

I just had my car in the shop to have them check out my OBDII readiness codes. This is the first time taking it to this particular shop. They had done work on my wife's Saab, and my Audi previously and they seemed very good. They also claimed to specialize in Porsche's as well, so I felt relatively confident. After speaking with one of the owners, he seemed familiar with 993's so I was even more confident.

Well, while it was in I went ahead and had them do an oil change since it was due and I hadn't gotten around to it yet. On my way back home I noticed that while driving (not idling), my oil level indicated slightly over half full. After slowing to a stop, the level was pegged out. Of course the shop was closed by then so I drove at low RPM's the rest of the way home. I also noticed in the meantime that they put conventional 10w30 oil instead of synthetic. I just assumed they would have known better.

So, after myself and the car cooled down overnight, I checked the dipstick this morning. Just as I suspected: the dipstick is reading full when the car is stone cold sitting in the garage. So, I obviously need to drain the oil out.

My questions: About how many quarts over-full am I? Any guesses? I'm also curious about what long term effect this would have if I hadn't realized it. (I plan to report all of this to the repair shop).

I want to go back to synthetic oil. I'm not sure if using the same oil filters will be an issue or not. I'm sure it's best to drain all the conventional oil out, but do the filters hold enough to be an issue?

Thanks in advance for any advice.
Brad

ca993twin

Synthetic oil mixes fine with conventional, so don't sweat it too much. There's lots of oil in the oil lines and front oil cooler... just drain what you can.

Its amazing how many shops have trouble doing an proper oil change on a 911.

chris walrod

Nothing like paying someone to learn on your car
If you are going to switch back to synthetic, just drain the oil from the tank and engine, refill with your oil of choice. Speaking of choice, have some choice words with this shop, and soon.

Avoid driving it until you can at least get the oil level down to where it is supposed to be. You dont want your engine sucking-in oil.. Sorry to hear this..

deltawedge

I learned the hard way on my '69 911. Filled the oil up on a cold engine, then drove it around untill it warmed up, and then let it idle in the driveway. You can imagine my surprise when plumes of smoke exploded from the rear of the car (not to mention the 3' puddle of oil).

For the record I was 2-3 qts overfull. The 993 is likely different, but probably somewhere close. If it was my car, I'd drain and refill with 15W50 Mobil1 but I'd look for a break from the shop on the cost of the oil.

BlackCar

You've given another reason to do as much DIY as possible on our cars. An oil and filters change is not that hard. Just time consuming.

993inNC

If the shop drained all of the oil (both filters, crank case, supply line and tank), then while you drive (if on a relatively flat surface),if you are at low rpms the gauge will read about half give or take and peg (when at opp. temps) at idle. Thats exactly what my car does and I do a complete change each time. I would be curious as to whether or not they noted how many quarts they used, this is a 12.4 quart system. My guage reads just like yours after a fresh change and I have DE'd with those gauge readings with no overflow. Other than the synth/dino oil issue, sounds like they may have actually done the right thing. You read over full on the stick because you checked it cold. Check it after a warm up and see what it says.....of course I don't bother with the stick, I use the gauge only but I go against the grain here. Driving my car just about every day in city driving, I feel I have a good understanding of what it is telling me.

Good luck......hell next time bring it to the beach, we can knock it out in no time

tlark

OT: I was at Carolina Beach on the 9th, was that your car I saw on 421 heading south. Can't be too many air coolers in Hanover County can there???

Marv

Sounds like a do-over to me. I would drain the carbonaceous punch out and refill with Mobil 1 15-50W.

The engine filter will hold oil and I would pull that to drain that as well. The oil tank filter is an easy pull.

If you drain both filters and both plugs, start with about 9 quarts and see where the level is after it warms up.

Good luck!

waybrig

Chris,
Your first sentence seems a little contradictory since you start off saying if you're driving at low rpms, then at the end you say at idle. Not sure which you mean, driving at low RPM (2-3K I assume) or idle (less than 1K). For the past two years, when driving at low RPM's the guage showed nothing but after idling for ~30 seconds it would come up to the halfway mark. After this change, when driving at low RPM's the guage was a little over 1/2 and when idling it was pegged out high. So, either I was running low for the past couple of years or they over-filled.

Regarding checking it when cold: That was ignorance on my part. I always assumed for some reason that the dipstick would read empty when cold, but I realized today that was probably a bad assumption.

Anyway, I emptied the thing out today and put 7 quarts of Mobil 1 in. Drove around for a while to bring it up to temp and ended up needing to add another quart. Now it's reading a little over 1/2 when warmed up and idling on level ground.

Ironically we spent last weekend in Wilmington. Next time I'll just bring it along and drop it off at your house!

deltawedge

The shop manual has the total oil capacity at 11.5L and 9L for an oil change (both approximate). The missing 2.5L is trapped in the front oil cooler and oil lines. As a reference, I use ~10.5 qts (~10L) at an oil change, which puts the oil level gauge midway when warm and idling (after thermostat opens and temp gets above the line at 8:00).

Do you get all 12.4 qts in at each oil change? I did the same once on my '69 911 when cold. After it warmed up (at idle) about a quart of oil was puked onto the right side heat exchangers with a big plume of smoke and 3ft oil puddle. The 993 must have a bigger tank.

When cold, the level will read lower not higher (oil expands when it gets hot). Since both the gauge and the level on the dipstick were set assuming the engine is fully warm and idling, reading it at any other set of conditions will not give meaningful readings (at least for determining correct oil level).

That said, an extra quart or so may not hurt, and if oil isn't getting pumped into your air box or onto the right side heat exchangers, then there may be no issue.

Terry Adams

The Porsche dealer (also Audi and VW) where I felt compelled to take my car during the first 50K in-warranty miles also claimed to specialize in Porsches. I had a less than satisfactory experience, and ever since my car has gone only to an independent. Where all I see is Porsches. Some of them being prepped for the track.

993inNC

Tom,
That was most likely me Hopefully I was behaving! Yeah there are only a few around that I know of. I am the only black widebody that I know of. There was an identical turbo, but he Ebay'd it bye, bye! Next time you're around, let me know, we'll get together....do lunch or something.

993inNC

Yeah man drop it off Sorry for the confusion. Sounds to me like you've been running low for a few years! You did understand my explanation though......in the 2K rpm range is what I meant (cruising in 5th or 6th gear) and mine runs roughly half gauge....pegs at idle. That is with a full change and every bit of 12 quarts (before running or driving to get the car "warm) . Stop by the next time you're around, I'm usually around.

993inNC

I want to say I read somewhere that the tank is 7 or 8 quarts.....could be wrong. But yes, with a full service, I get all 12 + in there.......starts to slow down after 10 quarts, so the last two take a while. I have never had a puke fest, or blow-by or anything similar. And I think my owners man. says 12.4 quarts for a complete change....don't have in front of me, but it hasn't done me wrong yet with the 12 quarts so.......