1987 PORSCHE 944 engine

If it fails to light up, the fuse is defective and
must be replaced. Replace black plastic
cover.
The central electrical system contains plug in
relays for various electrical switching
functions.
Defective relays should be tested and
replaced by an authorized Porsche dealer.
To prevent damage to the electrical system
we recommend having all work - including the
installation of electrical accessories -carried
out by your authorized Porsche dealer. . ,

Fuses and Relays
The individual circuits are protected by fuses
to prevent damage to electrical leads and
components due to short-circuits and
overload.
The fuse box with a black plastic cover is
located on the left side in the engine
compartment directly in front of pivot point for
left windshield washer arm.
The use of the fuses and relays is shown
in a list on the inside of the cover of the
fuses and relays.
Replacing a Fuse
Before replacing a fuse, turn off all
electrical components and the ignition;
remove the key. Replacing a fuse or relay with the
engine running or the ignition on could
cause electrical shock.

A blown fuse indicates an overload in the circuit. When a fuse is blown it is not sufficient
to merely replace it. The cause of the short
circuit or overload must be located. Fuses
should never be patched up with tin foil or
wire as this may cause serious damage
elsewhere in the electrical circuit.
Open snap-on latches and remove plastic
cover.
To find out whether a fuse is serviceable, pull
it out with the plastic pliers specifically
provided for this purpose. Insert the fuse at
the test point on relay (G 3). If the fuse is in
proper condition, the green indicator light will
come on.
Loudspeakers


When installing a radio or booster amplifier,
check that the output is compatible with the
capacity of the loudspeakers supplied with the vehicle.
Rated capacity in Watt (Sinus)
Front Rear
2x10 2x10
HiFi Audio Package 2 x 25 2 x 25
89


Battery-12 Volt
The battery is located under the front hood in
the cowl area.
A replacement battery should always have the same rating as the original equipment battery.
Specifications are printed on the battery
housing.
Before work is done on the electrical
system, the battery must be disconnected
to prevent short circuiting. First
disconnect the negative ground wire and
then the positive cable. To reconnect
battery, reverse the procedure.
Disconnecting the battery while the engine is running will damage the alternator. This
also applies to cars equipped with a
battery main switch.
Never drive the car with a disconnected battery as this will damage the alternator. WARNING

Do not lay tools or other metal objects on the battery as they could cause a short
circuit across the battery terminals.
Do not expose the battery to an open flame or electric spark. Hydrogen gas
generated by the battery is explosive.
Do not let battery acid come in contact with skin, eyes, fabric or painted
surfaces.
If you get electrolyte, which is an acid, in your eyes or on skin, immediately rinse
with cold water several minutes and call a doctor. Spilled electrolyte must be rinsed off at once with a solution of water and baking
soda to neutralize the acid and prevent
damage to fabric and metal.
Checking the electrolyte fluid level
The electrolyte fluid level in your battery can
be checked by unscrewing and opening the
filler vent caps of each cell. The fluid level
should meet the indicator mark in each cell. If
necessary, top off with distilled water.
How often water must be added depends on
operating conditions and on the time of year.
Generally, the electrolyte level must be
checked more often in the summer than in the winter, and more often when driving long distances.
Only fill up to mark, otherwise the electrolyte will overflow when the battery is being charged and cause damage.
Battery care
Battery should be securely mounted
Terminals and connections should be kept
clean and properly tightened. Corrosion can
be prevented by coating terminals and
connections with petroleum jelly or silicone
spray
Vent caps must be securely tightened to
prevent spillage
Winter operation
During the winter months, battery capacity
tends to decrease as temperatures drop.
Additionally, more power is consumed while starting, and the headlights, heater, rear window defogger, etc., are used more
frequently. Curtail unnecessary power
consumption, particularly in city traffic or when travelling short distances only. Let your
Porsche dealer test the battery's capacity
before winter sets in. A well charged battery
will not only prevent starting problems but will
also live longer.
Battery charging
Automotive batteries lose their efficiency when not in use. The charge available in your
battery can be measured with a hydrometer.
We recommend that battery voltage be tested
by your Porsche dealer who has the
appropriate equipment. If the car is not driven
for prolonged periods, the battery


90

must be charged at least every 6 weeks. A
discharged battery allows rapid formation of
sulfates, leading to premature deterioration of
the plates.
WARNING
Charge battery in a well ventilated area.
Keep away from open flame or electrical
spark. Do not smoke. Hydrogen gas
generated by the battery is explosive.
Electrolyte fluid that may spill during charging should be washed off with a solution of warm water and baking soda to neutralize the acid. If you get electrolyte in your eyes or on your
skin, immediately rinse with cold water for
several minutes and call a doctor.
Never charge a frozen battery. It may
explode because of gas trapped in the ice.
Allow a frozen battery to thaw out first. Never use a fast charger as a booster to start the engine. This may seriously damage the
vehicle's electrical system and the charger.
Fast charging a battery is dangerous and
should only be attempted by a competent
mechanic with the proper equipment.
Slow battery charging
WARNING
Heed all warnings and follow instructions
that come with your battery charger.


Disconnect battery cables and remove the
battery.
All vent caps should be open. If fluid level is low, it should be topped up to the full mark in
each cell.
Connect charger cables.
Charger cables must be connected
POSITIVE (+) to POSITIVE (+) and
NEGATIVE (-) to NEGATIVE (-).
Do not connect or disconnect charger cables while charger is operating. Switch on charger. Normally, a battery should be charged at no
more than 10 percent of its rated capacity.
Rated capacity of the battery in your vehicle
is listed on the battery housing.
After charging, turn off charger and disconnect charger cables. Tighten the vent caps and reinstall battery.



91

Emergency Starting with Jumper Cables
WARNING
Improper use of booster battery to start a
vehicle may cause an explosion.
Lead-acid batteries generate explosive
gases. Keep sparks, flame and lighted
cigarettes away from batteries.
Do not charge a frozen battery, thaw it out
first. Gas trapped in the ice may cause an
explosion.
No attempt should be made to jump start any vehicle with a low electrolyte level in the
battery.
Check electrolyte level of each cell. If
necessary, fill with distilled water to just
above plates.
Make sure the voltage of both batteries is the same. The capacity (Ah) of the booster battery
should not be lower than that of the
discharged battery.
Vehicle with discharged battery: turn off
lights and accessories, remove key, move
lever to N or P and set parking brake.
Vehicle with booster battery should not be
running. Disconnect ground cable.
Remove vent caps from booster battery and
discharged battery. Preferably lay a cloth
over open vents to reduce explosion hazard.

How to use jumper cables WARNING
To avoid serious personal injury and damage to the vehicle, heed all warnings
and instructions of the jumper cable
manufacturer. The jumper cables must be long enough so that neither vehicles nor cables touch
another.
Improper hook-up of jumper cables can
ruin the alternator.
Always connect POSITIVE (+) to POSITIVE
(+), and NEGATIVE (-) to ground on engine
block.
1. Connect clamp of plus-cable to positive (+) terminal of discharged battery (1).
2.
Connect clamp on opposite end of cable to
positive (+) terminal of booster battery (2).
3.
Connect clamp of minus-cable to negative
(-) terminal of booster battery (3).
4.
Connect clamp on opposite end of cable to
a bare metal part bolted directly to the
engine block or to the engine block itself (x)
of car with discharged battery. Connect
clamp as far away from battery as possible.
5. Start engine in the usual manner. If engine
fails to start, do not continue to crank but
contact nearest workshop.
6.
With engine running, remove jumper cables from both cars in exact reverse order: Steps 4 through 1.


7. Reconnect ground cable of booster battery.
A - Discharged Battery
B - Booster Battery
Do not try to start car by pushing or towing.
Damage to the catalytic converter, the
transmission, and/or other components of the
car may result.

92

Manual Operation of
Retractable Headlights
If the retractable headlights do not open, they
can be operated manually by turning the knob
on the end of the motor drive shaft located in
the front of the engine compartment. The
connecting rod assembly is designed in such
a way that it need only be turned to the left to
either close or open the headlights.
WARNING

Do not turn the knob on the drive shaft as
long as the automatic mechanism is
operating.
The motor may turn suddenly and cause
injury. Before turning the knob, check first
whether the motor will work by turning on the ignition and by depressing the light switch to
the second stop.
99

Emission Control System

In the Interest of Clean Air
Pollution of our environment has become a
problem that is of increasing concern to all of
us. We urge you to join us in our efforts for
cleaner air in controlling the pollutants emitted from the automobile.
Porsche has developed an emission control
system that controls or reduces those parts of
the emission that can be harmful to our
environment. Your Porsche is equipped with
such a system.
Porsche warrants the Emission Control
System in your new car under the terms and
conditions set forth in the Warranty &
Maintenance booklet.
You, as the owner of the vehicle, have the
responsibility to provide regular maintenance
service for the vehicle and to keep a record of
all maintenance work performed. To facilitate
record keeping, have the service performed
by authorized Porsche dealers. They have
Porsche trained mechanics and special tools
to provide fast, efficient service.
WARNING To assure efficient operation of the
Emission Control System:

Have your vehicle maintained properly and in accordance with the
recommendations described in your
Warranty & Maintenance booklet. Lack of
proper maintenance, as well as improper
use of the vehicle, will impair the function
of the emission control system and could
lead to damage.
Do not alter or remove any component of the emission control system unless
approved by the manufacturer.
Do not alter or remove any device, such as heat shields, switches, ignition wires, valves, etc., which are designed to protect your vehicle's emission control system. Do not continue to operate your vehicle if you detect engine misfire or other
unusual operating conditions.
Starting
Do not leave vehicle engine idling unattended after starting. If warning lights should come on to indicate improper
operation, they would go unheeded.
Extended idling also produces heat,
which could result in overheating or other damage to the vehicle or other property.

Parking
As with any vehicle, do not park or operate your vehicle in areas where
combustible materials, such as dry grass
or leaves, can come into contact with a
hot exhaust system.

Undercoating
Do not apply additional undercoating or rust proofing on or near the exhaust
manifold, exhaust pipes, catalytic
converter or heat shields. During driving
the substance used for undercoating
could overheat and cause a fire.

100

How Emission Control Works

When an automobile engine is running, it uses energy generated through the combustion of a mixture of air and fuel. Depending on whether
a car is driven fast or slowly or whether the
engine is cold or hot, some of the fuel
(hydrocarbons) may not be burned completely but be discharged into the engine crankcase
or exhaust system. Additional hydrocarbons
may enter the atmosphere through
evaporation of fuel from the fuel tank. These
hydrocarbons (HC), when released into the
air, contribute to undesirable pollution.
In addition, carbon monoxide (CO) and oxides of nitrogen (NOx) contribute to engine
emissions. They, too, are formed during the
combustion process and discharged into the
exhaust system.
To reduce these pollutants, your Porsche is
equipped with a precisely calibrated fuel
injection system to assure a finely balanced
air/fuel mixture under all operating conditions.

Oxygen Sensor
The oxygen sensor, installed in the exhaust
pipe continuously senses the oxygen content
of the exhaust and signals the information to
an electronic control unit. The control unit
corrects the air/fuel ratio, so that the engine
always receives an accurately metered air fuel mixture. .
Crankcase Ventilation
Through Crankcase Ventilation undesirable
emissions from the engine crankcase are not
permitted to reach the outside atmosphere.
These emissions are recirculated from the
crankcase to the air intake system. From here
the emissions mix with the intake air and are
later burned in the engine.
Catalytic converter
The catalytic converter is an efficient
"cleanup" device built into the exhaust system
of the vehicle. The catalytic converter burns
the undesirable pollutants in the exhaust gas
before it is released into the atmosphere.
The exclusive use of unleaded fuel is critically important for the life of the
catalytic converter. Therefore, only
unleaded gasoline without additives must
be used.
The catalytic converter will be damaged by

push or tow starting your vehicle
misfiring of the engine turning off the ignition while the vehicle is moving or
by other unusual operating conditions.
Do not continue to operate your vehicle
under these conditions, as otherwise fuel
can reach the catalytic converter. This
could result in overheating of the
converter.
Federal law prohibits use of leaded
gasoline in this car.
The Emission Control System and its other
related components are illustrated and
described on the following pages.
101

Emission Control System
1 Fuel pump
2 Fuel filter
3 Pressure damper
3a Pressure regulator
4 Injector
5 Auxiliary air valve
6 Air flow meter
7 Throttle valve switch
8 Temperature sensor
9 Engine temperature sensor
10 Speed sensor
11 Reference mark sensor (TDC)
12 Control unit
13 Ring gear
14 Ignition coil
15 Distributor
16 Relay (fuel pump / control unit)
17 Oxygen sensor
18 Catalytic converter
19 Muffler

102

Fuel Evaporation Control
Fuel Tank Venting
The expansion chamber and the roll over valve prevent fuel from escaping to the outside at
extreme high outside temperatures and when
the car is driven or parked at an incline or in
any other nonlevel position. The safety valve
works as a restrictor in the tank vent line between the expansion chamber and the
canister.
Vapor Control System and Storage
When the fuel tank is filled, vapors are
collected in the expansion chamber and filler
tube by a vent l
ine leading the vapors via a roll over valve to the activated carbon canister where they are stored as long as the engine does not run. During engine operation, the
vapors are stored in the activated carbon
canister as long as the control valve I
(ON/OFF valve) is in the OFF-position.
The control valve I stops purging of the
canister during all other operating conditions of the engine if the coolant temperature of the
engine is below a defined temperature.
Purge System
Fuel vapors from the carbon canister will be
mixed with fresh air taken from the ambient


1 Control valve II
2 Temperature switch
3 Air flow meter
4 Throttle valve 5 Intake manifold
6 Engine
7 Injection valve
8 Control valve I
(ON/OFF) 9 Expansion chamber
10 Charcoal canister
11 Roll over valve
12 Pressure regulator
13 Pressure damper 14 Fuel filter
15 Fuel pump
16 Fuel tank
of the carbon canister or fuel vapors from the
fuel tank. The vapors will be directed via a
control valve I and control valve II to the air
intake system housing. The control valve I has the following functions:
To stop purging of the canister during idle (the rich vapor flow from the canister would
influence the mixture characteristic).
To allow purging of the canister during all
other operating conditions of the engine.
The control valve II controls the vapor flow to
the engine.
103


http://www.9ss1.dk/porsche944

104

Technical Data
105

Engine 944 Number of cylinders
4
Bore 3.94 in. / 100 mm
Stroke 3.11 in. / 78.9 mm
Displacement 151 cu. in. / 2479 cm
3
Compression ratio 9.7:1
SAE net-power 147 hp/ 110 kW at 5800 rpm
SAE net-torque 140 ft lb / 190 Nm at 3000 rpm
Output per liter 59,3 SAE net-hp / 44,4 SAE net-kW
Max. permissible rpm 6500
Fuel octane rating Unleaded fuel only 91 RON (87 CLC or AKI ((R+M)/2) rating on fuel pump s in U.S.A.)

Spark plugs Bosch WR 7 DC or
Champion RN 9 YC
Electrode gap 0.028 + 0.004 in. / 0.7 + 0.1 mm
Battery capacity 12 volts, 63 Ah
Alternator output 1610W/115A
Firing order 1-3-4-2
Ignition timing Self-adjusting DME (Digital-Motor-E lectronic)
Ignition Transistorized ignition system with breake r less distributor
Belt for alternator Polyrib K6 1000 Lw
Belt for servo pump 9.5 x 950 LA
Valve clearance Hydraulic valve clearance compensat ion

106

Engine 944 S Number of cylinders
4
Bore 3.94 in. / 100 mm
Stroke 3.11 in. / 78.9 mm
Displacement 151 cu. in. / 2479 cm
3
Compression ratio 10.9:1
SAE net-power 188 hp/ 140 kW at 6000 rpm
SAE net-torque 170 ft lb / 230 Nm at 4300 rpm
Output per liter 75,8 SAE net-hp / 56,5 SAE net-kW
Max. permissible rpm 6800
Fuel octane rating Unleaded fuel only 95 RON (90 CLC or AKI ((R+M)/2) rating on fuel pump s in U.S.A.)

Spark plugs Bosch WR 7 DC
Electrode gap 0.028 + 0.004 in. / 0.7 + 0.1 mm
Battery capacity 12 volts, 63 Ah
Alternator output 1610W/115A
Firing order 1-3-4-2
Ignition timing Self-adjusting DME (Digital-Motor-E lectronic)
Ignition Transistorized ignition system with breake r less distributor
Belt for alternator Polyrib K6 1000 Lw
Belt for servo pump 9.5 x 950 LA
Valve clearance Hydraulic valve clearance compensat ion

107

Engine 944 Turbo
Number of cylinders
4
Bore 3.94 in. / 100 mm
Stroke 3.11 in. / 78.9 mm
Displacement 151 cu. in. / 2479 cm
3
Compression ratio 8.0:1
SAE net-power 217 hp/ 162 kW at 5800 rpm
SAE net-torque 243 ft lb / 330 Nm at 3500 rpm
Output per liter 87,5 SAE net-hp / 65,3 SAE net-kW
Max. permissible rpm 6500
Fuel octane rating Unleaded fuel only 90 RON (90 CLC or AKI ((R+M)/2) rating on fuel pump s in U.S.A.)

Spark plugs Bosch WR 7 DC
Electrode gap 0.028 + 0.004 in. / 0.7 + 0.1 mm
Battery capacity 12 volts, 63 Ah
Alternator output 1610W/115A
Firing order 1-3-4-2
Ignition timing Self-adjusting DME (Digital-Motor-E lectronic)
Ignition Transistorized ignition system with breake r less distributor
Belt for alternator Polyrib K6 1000 Lw
Belt for servo pump 9.5 x 950 LA
Valve clearance Hydraulic valve clearance compensat ion

108

Engine Design Specifications
Design
Operating cycle
Lubrication
Cylinder block
Cylinder head
Valve operation
Camshaft drive
Crankshaft
Fuel injection 4-cylinder, in-line engine, front mount with two ba
lance-shafts
4-stroke
Pressure oil circulation from oil sump,
full flow filter
Light metal
Light metal
Overhead camshaft
(944 S: 2 overhead camshafts)
Spur belt drive
Forged, 5 main bearings
AFC (Air Flow Control) Power Train
Manual transmission
Gear ratio
1st gear
2nd gear
3rd gear
4th gear
5th gear
Axle ratio Gear ratio 944
3.600:1
2.125:1
1.458:1
1.071:1
0.730:1
3.500:1
3.889:1 Gear ratio 944 S
3.500:1
2.059:1
1.400:1
1.034:1
0.829:1
3.500:1
3.889:1 Gear ratio 944 Turbo
3.500:1
2.059:1
1.400:1
1.034:1
0.829:1
3.500:1
3.375:1
Clutch
Power transmission Single plate dry disc, hydraulically operated
Double constant velocity joints and drive shaft
Automatic transmission 944
Gear ratio 1st gear
2nd gear
3rd gear
Reverse gear
Axle ratio
Clutch 2.714:1
1.500:1
1.000:1
2.429:1
3.455:1
Hydrodynamic torque converter
109

Filling Capacities
Engine oil With filter change approx. 6.34 (Turbo: approx. 6.87) U.S. qts. or 6 (Turbo: approx. 6.5) liters.
Check oil level with dipstick a few minutes after e ngine has stopped. The difference between
the max. and min. marks on the dipstick is approx. 1 U.S. qt. or 1 liter.
Only use brand name oil which has been tested and a pproved by Porsche.
Your authorized Porsche dealer will be glad to advi se you.
Porsche does not recommend the use of oil additives . See also "Engine Oils".
Cooling system with heating
Approx. 8,2 U.S. qts. or 7,8 liters. Factory filled to -31°F (-35°C). Only use phosphate-free
anti-freeze containing ethylene glycol recommended for aluminum engines and radiators.
Manual transmission
Approx. 0.53 U.S. gal. or 2.0 liters. Use hypoid oi l SAE 80 labeled "For Service API/GL4 or
Mil-L 2105".
Automatic transmission with
torque converter Approx. 1.72 U.S. gal. or 6.5 liters ATF Dexron®. At oil c hanges 3 U.S. qts. or 2.8 liters are
required.
Differential of automatic transmission
Approx. 1 U.S. qts. or 1 liter hypoid oil SAE 90 ac cording to API classification GL 5 or
Mil-L 2105 B.
Power steering
Approx. 0.63 U.S. qts. or 0.6 liter ATF Dexron®
Fuel tank Approx. 21.1 U.S. gals, or 80 liters including a re serve of 2.1 U.S. gals, or 8 liters.
Unleaded fuel only! Minimum octane rating 944 91 RO N (87 CLC or AKI ((R+M)/2) rating on fuel
pumps in U.S.A.), 944 S / 944 Turbo 95 RON (90 CLC or AKI ((R+M)/2) rating on fuel pumps in U.S.A.)
Brake fluid Approx. 0.42 U.S. pint or 0.2 liter. Only use brake fluid conforming to specifications
SAE J 1703, DOT 3 or DOT 4.
Windshield and headlight washer system
Approx. 1.59 U.S. gals, or 6.0 liters.
Refrigerant for air conditioning Approx. 33.5 oz or 950 g. Refrigerant R 12 (CCI2F2)
Cooling system mixing chart
(Approximate values)
Anti-freeze-Water
Consult your authorized dealer about
the approved anti-freeze mixtures. Temp, down to
-13° F (-25°C) -23° F (-30° C) -31° F (-35° C)
Anti-freeze
40%
45%
50% Water
60% 55% 50%
Anti-freeze

3.1 liters / 3.3 U.S. qts.3.5 liters / 3.7 U.S. qts.3.9 liters / 4.1 U.S. qts.
Water
4.7 liters / 5.0 U.S. qts.
4.3 liters / 4.5 U.S. qts. 3.9 liters / 4.1 U.S. qts.
110