'89 C4 Oil Leak

RiverCity911 · 08-30-2008, 02:01 PM

Right... unique thread title I'm sure.

I'm about 10 days into first time Porsche ownership and not incredibly auto-savvy. I can change oil, replace alternator, change plugs, etc on an old straight six Jeep. I'm a little apprehensive about tinkering with my new leaky friend.

Anyway, previous owner kept this Porsche well maintained with no oil spots on his garage floor. In the past 6-8 months, he dumped about 8k+ into changing gaskets, seals, hoses, clutch, belts, etc. A PPI by my mechanic noted some moisture/seeping at a couple location, but he didn't think it would be any immediate issue. Prev owner's mechanic revisited the noted areas and tightened some clamps and replace another hose. So, informed of the potential oil issues, I purchased the car "as-is" for a lowered price and figured I'd deal with it when it reared it ugly head.

Well, 10 days and about 100 miles later, my driveway proudly displays a 3' long by 1' wide streak of black gold. The leak seems to the dripping down from a rectangular item just forward of the right rear tire and about 12" in from the right side. I haven't crawled under yet. I wanted to pick your brains, before I get too dirty under there. Not knowing Porsches, would there be any funky issues will driving until nicely warmed up, then parking for 7 days on a pretty good incline? I know there is a secondary reservoir or something that the oil goes to upon shut down, so could it be realted to that? Do I need to idle on level ground or anything odd like that?

Any ideas or answers would be appreciated.
Thanks, Chris

Flieger · Flieger's Garage

Sounds like the location of the oil tank. Maybe a leaky fitting where a hose joins connects to the tank? Check the drain plug.

RiverCity911 · 08-30-2008, 03:34 PM

Did I mention I'm a new owner? The rectangular item I saw is actually the back edge of the forward belly pan.

I need to get a jack and stands to be able to get underneath the car. Looking from the side, I can't see much.

RiverCity911 · 08-30-2008, 04:01 PM

When I first start the engine, the oil level gauge is low, really low to almost red zone low. Should I put in a quart or two in order to safely warm the engine up to actually check the oil? If I check it cold with dip stick, what should that read? For the quantity of oil these things hold and the small (maybe half-quart) amount on my driveway, it seems like there should be plenty left inside.

I did pull the car into the garage (level ground).

Flieger · Flieger's Garage

The oil drains from the tank to the sump as the car sits for a day or longer. This may be why the gauge reads low, especially if there is a leak in the tank. Does the gauge register higher (normal) level when you run it a little?

1/2 quart loss shouldn't hurt as long as you keep the oil above the lower line when you check the oil on a level surface, engine up to temperature and at idle.

I would not add oil unless I saw it at the lower dip stick line when measured through the proper process.

Flieger · Flieger's Garage

Where is Fair Oaks? If you're ever in my neighborhood, I would be happy to lend a hand and tools.

RiverCity911 · 08-30-2008, 05:09 PM

By Hazel and Madison, off Hwy-50 (Nor Cal). Thousand Oaks is west of Pt. Mugu, right.

Flieger · Flieger's Garage

That's right.

Well, if you happen to be around for the great roads or going to the California Festival of Speed or Long Beach ALMS race next year, let me know.

Hamptonsam · 08-31-2008, 01:43 AM

Just make sure you always check oil level when at operating temps. When I first got mine, I checked when cold and added oil. It was the wrong thing to do. I overfilled because of this.

Generally the gauge on the dash is pretty acurate, however mine does not register until the temperature is hot enough to open the thermostat to the front oil cooler. Then the needle will rise. (Freaked my wife out when she was driving it since it looks like you are very low on oil for a while.)

Good luck with the leaks. I have a 90 and have aweful leaks. I am trying to tackle them myself as I cannot afford a top end rebuild right now.

Duck

douglas751 · 08-31-2008, 05:33 AM

The Dealer that sold me my first 964 did the same thing. You overfilled the oil because you checked it when the car was cold. You can be 1 quart low on this car and it would not matter much, but 2 quarts over is a small problem. Take your other car to Autozone and buy a siphon pump hose. Stick that into the oil fill snout and suck out 2 quarts before you run the car again. Some will tell you not to wash the engine, so maybe just use your hose for that but be sure that the engine is cold, not hot, so that you do not crack anything. Simple Green should do the trick. Most likely you will have oil on top of the heat exchanger exhaust manifolds and if you do not wash that off it will smoke.

When you get a chance, take the car to a shop that knows air cooled Porsche and get an oil change. Or, do it yourself after reading the procedure on-line. You never know what was put into that engine before you owned it.

Good luck!

RiverCity911 · 08-31-2008, 10:14 AM

(Freaked my wife out when she was driving it since it looks like you are very low on oil for a while.)

Include me in that category. I haven't added any oil. I just wanted to clarify that a low oil reading at first start-up didn't necessarily equate to low oil.

Thanks for the input!