GMC chevrolet camaro 2000 Service Manual page 793

6-26 Engine Mechanical - 3.SL Engine
Momentary Noise on Engine Startup
Step
Action
Value(s)
Yes
No
DEFINITION: Momentary noise when the engine is started, usually cold
This condition is normal. Oil drains from the valve lifters
which hold the valves open when the engine is not
1
running. The valve lifter needs a few seconds to fill with oil
-
after you start the engine.
Repair as No correction is
Does the noise.continue after a few seconds? required needed
Intermittent Noise on Idle Only
Step
Action
Value(s) Yes
No
DEFINITION: Intermittent noise on idle that disappears when engine speed increases
1.
Disassemble the valve lifters.
··.
1
2. Check the valve lifters for any dirt. Check the valve
-
lifters for a pitted or damaged check ball.
ReplaCe the
Are the valve lifters dirty or damaged?
.
valve lifter System OK
Noise at Idle
Step
I
.
Action I
Value(s)
I
Yes
I No
DEFINITION: Noise at idle or with hot oil that quiets at higher engine speeds or with .cold oil
1
I
Inspect the lifter for a high leakdown rate.
I I
Replace the
I
No correction is
-
Does the lifter have
a
high leakdown rate?
faulty.lifter needed
Noise at High Vehicle Speeds
Step
Action
Value(s) Yes
No
DEFINITION: Noise at.high RPM only
.
Check for a high engine oil level. An oil level above the
.
(
FULL mark allows the crankshaft counterweights to churn
1
the oil into a foam. When the foam is pumped into the
-
lifters, the lifters become noisy since a solid column of oil
ensures the proper operation. )
Drain the oil to
Is th.e oil level too high? the proper level Go to Step 2
Check for a low engine oil level. An oi.1 level below the
2
ADD mark allows the oil pump to pump .air a.t high speeds.
-
This causes noisy valve lifters.
Add oil a.s
Is the oil level too low? required Go to Step 3
3
Check the oil pan.
-
Repair as
Is the oil pan bent against the oil pump pickup?
· required
Go to Step 4
4
Check the oil pump screen.
Repair as
-
Is the oil pump screen bent or loose? required System OK
(