GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 465
Fig. 12: Muffler hanger attachment
ENGINE RECONDITIONING DETE RMINING ENGINE CONDITION
Anything that generates heat and/or friction will eventually burn or wear out (i.e.
a light bulb generates heat, therefore its life span is limited). With this in mind, a
running engine generates trem endous amounts of both; friction is encountered
by the moving and rotating parts inside the engine and heat is created b\
y
friction and combustion of the fuel. Ho wever, the engine has systems designed
to help reduce the effects of heat and fr iction and provide added longevity. The
oiling system reduces the amount of fr iction encountered by the moving parts
inside the engine, while the cooling system reduces heat created by friction and
combustion. If either system is not main tained, a break-down will be inevitable.
Therefore, you can see how regular main tenance can affect the service life of
your vehicle. If you do not drain, flush and refill your cooling system at the
proper intervals, deposits will begin to accumulate in the radiator, thereby
reducing the amount of heat it can extrac t from the coolant. The same applies to
your oil and filter; if it is not changed often enoug h it becomes laden with
contaminates and is unable to properly lubricate the engine. This increases
friction and wear.
There are a number of methods for evaluat ing the condition of your engine. A
compression test can reveal the condition of your pistons, piston rings, cylinder
bores, head gasket(s), valves and valve seat s. An oil pressure test can warn
you of possible engine bearing, or oil pump failures. Excessive oil consumption,
evidence of oil in the engine air intake area and/or bluish smoke from the tail
pipe may indicate worn piston rings, worn valve guides and/or valve seals. As a
general rule, an engine that uses no more than one quart of oil every 1000
miles is in good condi tion. Engines that use one quart of oil or more in less than
1000 miles should first be checked for oil leaks. If any oil leaks are present,
have them fixed before dete rmining how much oil is consumed by the engine,
especially if blue smoke is not visible at the tail pipe.
COMPRESSION TEST
A noticeable lack of engine power, excessive oil consumption and/or poor fuel
mileage measured over an extended period are all indicators of internal engine
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 469
ENGINE OVERHAUL TIPS
Most engine overhaul procedures are fair
ly standard. In addition to specific
parts replacement procedures and specifications for your individual engine, this
section is also a guide to acceptabl e rebuilding procedures. Examples of
standard rebuilding practice are given and should be used along with specific
details concerning your particular engine.
Competent and accurate machine sh op services will ensure maximum
performance, reliability and engin e life. In most instances it is more profitable for
the do-it-yourself mechanic to remove, clean and inspect the component, buy
the necessary parts and deliver these to a shop for actual machine work.
Much of the assembly work (crankshaft, bearings, piston rods, and other
components) is well within the scope of t he do-it-yourself mechanic's tools and
abilities. You will have to decide for your self the depth of involvement you desire
in an engine repair or rebuild.
TOOLS
The tools required for an engine overhaul or parts replacement will depend on
the depth of your involvement. With a few exceptions, they will be the tools
found in a mechanic's tool kit (see Gener al Information & Maintenance in this
repair guide). More in-depth work will requ ire some or all of the following:
• A dial indicator (reading in thousandths) mounted on a universal base
• Micrometers and telescope gauges
• Jaw and screw-type pullers
• Scraper
• Valve spring compressor
• Ring groove cleaner
• Piston ring expander and compressor
• Ridge reamer
• Cylinder hone or glaze breaker
• Plastigage®
• Engine stand
The use of most of these tools is illustra ted in this section. Many can be rented
for a one-time use from a local parts jobber or tool supply house specializing in
automotive work.
Occasionally, the use of special tools is called for. See the information on
Special Tools and the Safety Notice in General Information & Maintenance
before substituting another tool.
OVERHAUL TIPS
Aluminum has become extr emely popular for use in engines, due to its low
weight. Observe the follo wing precautions when handl ing aluminum parts:
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 495
Again, rotate the engine, this time
to position the number one cylinder bore
(head surface) up. Turn the crankshaft until the number one piston is at the
bottom of its travel, this should allow t he maximum access to its connecting rod.
Remove the number one co nnecting rods fasteners and cap and place two
lengths of rubber hose over the rod bolts/studs to protect the crankshaft from
damage. Using a sturdy wooden dowel and a hammer, push the connecting rod
up about 1 in. (25mm) from the cranks haft and remove the upper bearing insert.
Continue pushing or tapping the connecti ng rod up until the piston rings are out
of the cylinder bore. Remove the piston and rod by hand, put the upper half of
the bearing insert back into the rod, in stall the cap with its bearing insert
installed, and hand-tighten the cap fasteners. If the parts are kept in order in this
manner, they will not get lost and you wil l be able to tell which bearings came
form what cylinder if any problems are discovered and diagnosis is necessary.
Remove all the other piston assemblie s in the same manner. On V-style
engines, remove all of the pistons from one bank, then reposition the engine
with the other cylinder bank head surface up, and remo ve that banks piston
assemblies.
The only remaining component in the engine block should now be the
crankshaft. Loosen the main bearing ca ps evenly until the fasteners can be
turned by hand, then remove them and the caps. Remove the crankshaft fro\
m
the engine block. Thoroughly clea n all of the components.
INSPECTION
Now that the engine block and all of its components ar e clean, it's time to
inspect them for wear and/or damage. To accurately inspect them, you will need
some specialized tools:
• Two or three separate micromet ers to measure the pistons and
crankshaft journals
• A dial indicator
• Telescoping gauges for the cylinder bores
• A rod alignment fixture to check for bent connecting rods
If you do not have access to the proper tools, you may want to bring the
components to a shop that does.
Generally, you shouldn't expect cracks in the engine block or its components
unless it was known to leak, consume or mix engine fluids, it was severely
overheated, or there was ev idence of bad bearings and/or crankshaft damage.
A visual inspection should be performed on all of the components, but just
because you don't see a crack does not mean it is not there. Some more
reliable methods for inspecting for cracks include Magnaflux, a magnetic
process or Zyglo, a dye penetrant. M agnaflux is used only on ferrous metal
(cast iron). Zyglo uses a spray on fluoresce nt mixture along with a black light to
reveal the cracks. It is strongly recommended to have your engine block
checked professionally for cracks, especia lly if the engine was known to have
overheated and/or leaked or consumed coolant. Contact a local shop for
availability and pricing of these services.
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 573
7. Install the retaining bracket.
8. Connect the negative battery cable.
ELECTRONIC ENGINE CONTROLS
COMPUTER COMMAND CO NTROL (CCC) SYSTEM
The Computer Command Control (CCC) Sy stem is an electronically controlled
exhaust emission system that can m onitor and control a large number of
interrelated emission cont rol systems. It can monitor various engine/vehicle
operating conditions and then use this in formation to control multiple engine
related systems. The CCC syst em is thereby making constant adjustments to
maintain optimum vehicle performance und er all normal driving conditions while
at the same time allowing the catalyti c converter to effectively control the
emissions of HC, CO and NO
x.
OPERATION
The Electronic Control Module (ECM) is required to maintain the exhaust
emissions at acceptable le vels. The module is a sma ll, solid state computer
which receives signals from many source s and sensors; it uses these data to
make judgements about operating conditions and then control output signals to
the fuel and emission systems to ma tch the current requirements.
Inputs are received from m any sources to form a complete picture of engine
operating conditions. Some inputs are simp ly Yes or No messages, such as that
from the Park/Neutral switch; the vehicle is either in gear or in Park/Neutral;
there are no other choices. Other data is sent in quantitative input, such as
engine rpm or coolant temperature. T he ECM is pre-programmed to recognize
acceptable ranges or combinations of si gnals and control the outputs to control
emissions while providing good driv eability and economy. The ECM also
monitors some output circuits, making sure that the components function as
commanded. For proper engine oper ation, it is essential that all input and output
components function properly and comm unicate properly with the ECM.
Since the control module is programmed to recognize the presence and value
of electrical inputs, it will also note the lack of a signal or a radical change in
values. It will, for example, react to the loss of signal from the vehicle speed
sensor or note that engine coolant temperature has risen beyond acceptable
(programmed) limits. Once a fault is recognized, a numeric code is assigned
and held in memory. The SERVICE ENGIN E SOON Malfunction Indicator Lamp
(MIL), will illuminate to advise the operator that the system has detected a fault.
More than one code may be stored. Although not every engine uses every
code, possible codes range from 12-999. Additionally, the same code may carry
different meanings relative to each engine or engine family. For example, on the
3.3L (VIN N) engine, code 46 indicates a fault found in the power steering
pressure switch circuit. The same code on the 5.7L (VIN F) engine indicates a
fault in the VATS anti-theft system.
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 577
MALFUNCTION INDICATOR LAMP
The primary function of the MIL is to adv
ise the operator and the technician that
a fault is detected, and, in most cases, a code is stored. Under normal
conditions, the malfunction indicator la mp will illuminate when the ignition is
turned ON. Once the engine is started and running, the ECM will perform a
system check and extinguish the lamp if no fault is found.
Additionally, the lamp can be used to retrieve stored codes after the system is
placed in the Diagnostic Mode. Codes ar e transmitted as a series of flashes
with short or long pauses. When the syst em is placed in the Field Service
Mode, the dash lamp will indicate open loop or closed loop function to the
technician.
INTERMITTENTS
If a fault occurs intermittently, such as a loose connector pin breaking contact
as the vehicle hits a bump, the ECM will note the fault as it occurs and energize
the dash warning lamp. If the problem se lf-corrects, as with the terminal pin
again making contact, the dash lamp will extinguish after 10 seconds but\
a code
will remain stored in the ECM memory.
When an unexpected code appe ars during diagnostics, it may have been set
during an intermittent failure that self-c orrected; the codes are still useful in
diagnosis and should not be discounted.
OXYGEN SENSOR
OPERATION
An oxygen sensor is used on all models. The sensor protrudes into the exhaust
stream and monitors the oxygen content of the exhaust gases. The difference
between the oxygen content of the exhaust gases and that of the outside air
generates a voltage si gnal to the ECM. The ECM monitors this voltage and,
depending upon the value of the signal rece ived, issues a command to adjust
for a rich or a lean condition.
No attempt should ever be made to meas ure the voltage output of the sensor.
The current drain of any conventional vo ltmeter would be such that it would
permanently damage the sensor.