993 Faq Frequently Asked Questions about the Porsche 1994-1997 993


993 Manual Transmission Oil Change

Filed under: Maintenance — admin @ 10:00 pm

For info, the G50 transmission model is the manual transmission type installed in the 911 since 1987. The G64 is the AWD version of the G50 installed in the C4. Now, I recently did a transmission oil change on my 993, and figured I’d let you folks know what I did. I tend to think that this should be applicable for all 911 G50/G64 model manual transmissions, but I am not guaranteeing this.

Items you will need:
– 10 mm Allen-headed socket (3/8″ drive might be best)
– 2 22mm X 27 mm crush washers. These are generally aluminum; Porsche no. is 900 123 011 30
– Long 3/8 drive ratchet, or a 1/2 drive ratchet with a 3/8″ X 1/2″ adapter
– Torque wrench that can accurately go to about 30 ft-lbs (1/2″ drive might be too large)
– 4 quarts of transmission oil. Check your owner’s manual, but mine specified 75W90 GL5 spec. This is readily available in Mobil 1
– Good floor jack and jack stand
– Catch basin to catch oil
– About 5 feet of 3/4″ or 7/8″ clear vinyl tubing

Now, jack up the car at the left rear as high as needed to get under the car comfortably, and secure on a jack stand. On 964 and 993, remove the engine and transmission undercovers. You should be able to see the transmission drain and filler plugs easily; the drain plug is at the bottom under the differential, and the filler is on the left side of the transmission forward of the driveshaft.

The drain and filler plugs are nice high-quality steel fittings. ALWAYS start with unscrewing the filler plug; this way, if it won’t come out you just drop the car and bring it into someone who does this for a living (if you drain the oil first THEN find you can’t remove the filler plug, you’re in big trouble). In my case, the plugs unbolted easily.

With the filer plug unscrewed, you can position your catch tank and remove the drain plug. With the car at an angle, you might not get out all the old oil; I found if I lowered the car back to level, I was able to drain the transmission better. There is a magnet at the bottom of the plug; you will invariably find it loaded with steel shavings. Clean off the plug, remove the old crush washer, and replace with a new one. Reinstall the plug and torque to 22 ft-lbs (30 N-m). This is not much, so be careful. Also clean up the filler plug, install a new crush washer, and place it aside.

You can now fill the tranny with fresh fluid. Easy way I found to do this was to route the tubing through the left rear wheel housing from right above the top of the tire, down around the suspension, then stick the tubing end into the filler port. Make sure that the lowest part of the tubing is at the transmission filler hole. You can now start adding oil via the other tubing end in the wheel well. I found I could speed up the oil addition by cutting the tip off the oil cannister and squeezing it.

Check your owner’s manual to see how much oil to add. For info, on the 993 the G50 takes 3.6 liters and the G64 takes 3.8 liters (a quart is 0.946 liters, for info). When done, pull out the tubing, install and torque the filler plug (22 ft-lbs), then lower the car and congratulate yourself.



Filed under: Maintenance — admin @ 9:51 pm

I tend to be somewhat of a “wrench twirler’, being willing to do work on my cars (even sometimes to their detriment). Reasons for this are somewhat financial (I don’t charge myself labor), somewhat timing (trying to get time to drop the car off & arrange to pick it up at a dealer or shop is a major nuisance, especially in these days of possibly being canned due to “downsizing”), but mostly – I enjoy doing it! So, when someone told me that changing oil and filters on a 993 was a major job, I just figured maybe taking 1 hour rather than 1/2 hour like on my old Carrera. Well, I have since found out that this job can consume the better part of a Saturday. Worse, unless you’re careful, you can also “paint” your garage floor with about 9 quarts of old, dirty oil!.

For those of you who intend to tackle this job yourself, value from my experience. For those of you who are sane and leave Porsche maintenance to the pros, hope you can get a good laugh from all of this.

Items needed:
900 123 118 30 Seal washer for oil tank drain plug, 22x27mm
900 123 118 30 Seal washer for engine drain plug, 22x27mm (thru ’95)
900 123 095 30 Seal washer for engine drain plug, 21x26mm (’96 on)
999 701 269 40 O’ring for oil tank drain plug, 11X2.5 mm
993 107 203 02 Engine oil filter
993 207 201 01 Oil tank oil filter

15mm 6-point socket (can damage drain plugs with 12-point)
15 mm box end wrench (6-point preferable, if you can find one)
Large flat-head screwdriver
Medium Phillips screwdriver
Oil filter wrench (type that clamps on end of filter -bring new filter to store & match)
Hydraulic jack
Jack stand
Torque wrench

OK, let’s get started!

1) Jack up right rear of car, remove wheel. Put jack stand under car to hold weight.
2) Unscrew screws holding rear fender liner in place, remove liner.
3) Unscrew screws holing entire rocker panel cover in place up to front fender, swing cover down out of way.
4) Unscrew engine cover (5 screws) and transmission cover (6 screws, as I remember) and remove. These are held in place with Dzus style fasteners; 1/4 turn unlocks and releases the screws.
5) Loosen slightly the oil tank drain plug (WARNING! IT IS ALUMINUM, AND APPEARS VERY EASY TO STRIP THE HEX HEAD!)
6) Put wheel back on, lower car
7) Remove oil tank drain plug, drain oil. Renew O’ring on drain plug, put new sealing washer on plug,tighten to 40 ft-lbs. For info, had to drop car at this point because the oil tank drain is right over the jack location.
8) Jack up car, remove wheel. Renew oil tank oil filter.
9) Remove the right-side heater flapper valve (bottom of engine). Remove rubber heater duct from flapper valve to heater valve (above and in front of axle).
10) Unscrew the engine drain plug (left side of engine half, by left heater flapper valve). This will apparently only take a box-end wrench; there is insufficient room for a socket. If the plug won’t move, try rapping the wrench with a hammer.
11) Place new seal washer on drain plug, tighten to 40 ft-lbs.
12) Use filter wrench and long extension to unscrew the engine filter. This is in a very tight area; might have to unbolt a drain tube adjacent to the filter (I haven’t). Replace filter.
13) Reinstall the rocker panel cover, wheelwell liner, and transmission cover.
14) Add six quarts of oil.
15) Start engine, let idle, and slowly add last 3 quarts. Go for a drive to warm up engine, then top-up as necessary.

A few last items:
a) When replacing the drain plugs, Porsche makes no mention of using an anti-seize compound. I use one out of habit.
b) When replacing filters, make sure to lube the rubber oil seal with engine oil, then screw on firmly HAND TIGHT ONLY. I’ve got a good horor story of trying to remove a filter tightened in place with a wrench. This hand-tight installation might be hard to do on the engine filter; recommend using filter wrench with extension, hold HEAD of ratchet on extension end and tighten moderately. Hopefully, you can remove the filter wrench later.
c) Notice I didn’t reinstall the engine panel. Bruce Anderson has made the recommndation to leave this panel off the 993 and 964 C2/C4; this panel causes excessive heat retention and premature valve guide wear.

Fun, wasn’t it? And all it took was 4 hours.


15K / 30K service and costs

Filed under: Maintenance — Jeff 993TT @ 5:22 pm

Every 15K miles/24K km:

Change engine oil
Diagnosis system: read out fault memory
Anti-pollen filter: replace filter element
Oils and fluids: visual inspection for leaks
Crankcase ventilation: check tightness of hose connections
Fuel system: visual inspection for damages, clearance and tightness of line connections
Intake air: check hoses, lines and connections for tightness
Parking brake: check free travel of parking-brake lever
Brake hoses and lines: visual inspection for clearance, damage and corrosion
Brake fluid: check level
Brake system: visual inspection of brake pads and discs to check for wear
Clutch: check play or final position of clutch pedal
Throttle linkage: check for smooth movement and full throttle opening [this one gets inspected every time the car is driven, right?]
Resonance flap and Varioram: check operation (Carrera only)
Steering gear: visual inpection of the bellows for damage
Tie rods: check play and dust caps
Power assisted steering/clutch: check fluid levels
Ball joints: visual inspection of dust caps for damage, check tightness of wheel alignment adjustment/mounting bolts
Manual transmission/axle drives: check oil level
Automatic transmission: check fluid level
Drive shafts: visual inspection of boots for leaks and damage
Exhaust system: visual instpection for leaks and damage, check tightness
Tires: check condition and correct tire pressure
Door hinges: lubricate
Door locks, hood locks and safety hook on front hood: check for tightness and operation
Safety belt: check operation and condition
Seals for doors, hood and roof: remove rubber residue from body seal contact areas, apply suitable lubricant
Vehicle lights: check operation
All headlights: check setting
Horn: check operation
Windshield washer, headlight washer: check fluid level, nozzle aim and washer fluid freeze protection level for the winter season and whcih wiper system operation
All other electrical equipment as well as indicator and warning lights: check operation
During road or dynamometer test:
Brake pedal, parking brake, clutch, automatic speed control, steering, heating, air conditioner and instruments: check operation
Oils and fluids: visual inspection for leaks

Additional service every 30K miles/48K km:
V-belt and Polyrib belt: check condition and tension
Replace spark plugs
Air filter: replace filter element
Replace both engine oil filters
Automatic transmission: change ATF and ATF filter
Drive belt for power steering pump: check condition

Additional service every 60K miles/96K km:
Manual transmission and axle drives: change oil
Automatic transmission: change oil in differential

The manual also recommends brake system and airbag system maintenance every two years.


The spark plug change on the 30K service is one of the most difficult. Costs for the 30K service will be about $1000-$1700.

The 15K service runs from about $700-1200.


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