afinepoint

It has been written that air cooled engines shall leak. - Due to the tolerances dictated by the need for expansion and contraction of these engines vice the tighter temperature control of their water cooled brethren.

Others say their (these) engines are (should be) leak tight.

The local garages and tech inspectors at the DE events I have attended don't bat an eye unless you are forming a pool in front of them.

Where is the line?

Reg

TerryH

Not sure there is a line drawn. It's more of personal tolerance and expense of repair. If the case is leaking a little, I wouldn't be in hurry to spend big $$$ to fix it unless it could get worse or cause other problems. There is always a chance of fire if there is oil accumulating and hitting the hot exhaust.

When I bought my SC it had one leak from an oil line. After replacement, I now have a leak free car. I can drive it anywhere and park on friends new driveways without worry. No smoke from wet heat exchangers and no smoke in the cabin.

I feel fortunate as I have seen drip pans under many leakers.

fixnprsh

it is all in how much you can tollerate and afford. Personally I hate a leaky car. Hoever I came to a tolerance with my Landcruiser, facing a saturdays worth of messy axle work for $20 worth of felt seals, or wiping the grease and gear oil off the inside of the wheels when I wash it. Needless to say conveniance (lazyness?) won out.

I've built and seen motors that stay dry for a long time, with age though, they will all leak from somewhere as seals harden. If you only fix two of your four leaks, thats 50%, so look at it that way. they are all pretty easy to do. the exception for cost/value, is a rear main, front crank, nose bearing, case. The big three, breather hose, thermostat and switch arent too bad on the Carrera, the SC is a pain to do these.

BTW I see alot more water cooled 996's that are leaking much more oil than any Carrera, SC that comes in to the shop. The 996 rear main hemorages oil like it would bleed to death, along with intermediate shaft seals, cam solenoid flanges, rear sump, breather, cam cover, cost thousands to do. I have had cars that need a rear main seal every 6-8K miles, so look at the positve on the old cars, atleast you dont have an $900 a month payment and still have to pay to have it fixed

mschafer71

Less than one quart per 1000 miles is "about the standard", is the loss is thru leaks in the engine or oil getting by worn rings or guides determines the priority of dealing with problem. Leaky engine vs. worn engine, or combination which is most common.

if you want to read an excellent article on oil types: http://motorcycleinfo.calsci.com/Oils1.html

afinepoint

After a long drive the engine creates three or four oil spots from one to two or so inches in diameter by morning. A square of paper towel will clean it up.

I picked up some concentrated cleaner and parked on the gravel. Tomorrow I plan to scrub the engine to at least find the leak(s). One for sure is below the AC compressor - probably a valve cover. Things got worst years ago when I changed from dino to Mobil 1.

It's time for another valve adjustment (100,000 miles). Hopefully the garage can take care of the vavle cover leaks.

Thanks for the information.

Reg

Edward

Hi Reg,

Whether I'd address oil leaks depends on their source (which determines cost or your DIY labor) and amount leaking. If it were valve cover gaskets, oil rtn tubes, or an oil line, then I'd fix it simply because its cost/benefit to me is worth it. For an engine-out job, however, it better be leaking like a sieve and have other problems to boot ...but that's just me Keep in mind, too, that leaks are certainly NOT out of the ordinary with the aircooled 6s, and what you're describing isn't really too bad. But only you can determine what you're comfortable with.
Try cleaning out the engine as best you can and then take it out for a good, spirited drive. Then throw the car up in on stands and see where it's leaking from. That might help you decide right there. Post back and let us know.

Edward

afinepoint

Thanks Edward,

I spent the morning scrubing. The engine is now drying in the sun. The worst of the buildup was inside the fan housing. I decide to do more than just the block. After my chores things should be dry and then -you twisted my arm its off down the road. It's 76° and full sun here in Richmond, VA!

Will report back on what I find. If I make it back.

Reg

afinepoint

The car has set for about two hours and no drips yet. The garage floor is clean. I can run my finger along the crankcase centerline seam and get oil. So there is a source but I am not about to crack the engine open for such a small leak. The leak is too small to quantify.

I take a look again in the morning.

Reg

mschafer71

oil in the fan housing and on the case split line sounds like my leak from the front crankshaft/pulley seal.

afinepoint

The car has set for 48 hours w/o any drips on floor. The oil must be accumulating somewhere and then dripping.

At least I know the leaks are not gross.

I will check on things at the track this weekend. If it doesn't leak (excessively) at VIR it's not going to.

Reg
84 Targa with 100,000 miles.

Edward

Hi Reg,

48hrs and no leak to the floor? ...that's good news. Are you sure that the oil you feel from the crankcase seam is really not dribbling from up higher (especially deceiving if the oil is clean). If it Is the seam, I'd definitely live with it. But also try to confirm that it is NOT coming from the "low" side of the engine like valve cover gaskets, oil tubes, or cylinder head or base? If there's a leak above these points, you may want to poke around really closely with a flashlight to see where it's coming from. But at least it's a slow one. Have fund at VIR!

Edward

Dan Cobb

Anything more than you are willing to clean up or replace frequently is a gross leak.
I don't really consider it a leak...
more like a constant (albeit slow) oil change!
+++

afinepoint

It's got to be pooling on top. Prior to cleaning oil was everywhere along the exhaust pipes especially at the gaskets. It must have been long term accumulation.

Thanks Edward. I hope the weather cooperates.

Reg

afinepoint

After the VIR weekend and a 2 1/2 hour drive home the drips have returned. About 2 teaspoons worth be next morning. There appears to be two leaks. They are coming from somewhere on the top. I have pulled wheels and checked the underside. I can see oil on top of the engine below the compressor. There is 1/4 inch tubing tapping in below the compressor next to a sensor and running across and connecting behind cylinder #4 that looks wet. I will tighten this. This is all above the larger spot on the floor. The second leak is on the left side and only produced one drip by morning.

Will continue to chase things when I have more time. The leak(s) are not bad enough to hold my full attention.

Thanks for the input.

Reg

Edward

Hi Reg,

Can you take a pic of the area where you see the oil leaking from? Now I'm really curious

Edward