Daewoo Nubira User Manual page 414

1A – 6IGENERAL ENGINE INFORMATION
Step
1 Is there a light knock when the engine is hot?
2 Is detonation or spark knock evident?
3 Check the engine timing and the fuel quality.
Was the problem found?
4 Inspect the torque converter bolts.
Are the bolts loose?
5 Tighten the torque converter bolts.
Is the repair complete?
6 Inspect the manifold.
Is there an exhaust leak at the manifold?
7 Tighten the bolts or replace the gasket.
Is the repair complete?
8 Check the rod bearing clearance.
Is the clearance within the specified value?
9 Replace the rod bearings as necessary.
Is the repair complete?
Knocks During Initial Start–Up But Lasts Only a Few Seconds
Step
1 Does the engine knock during initial start–up but last
only a few seconds?
2 Check the engine oil.
Is the proper viscosity oil used in the crankcase?
3 Install oil of the proper viscosity for the expected
seasonal temperatures.
Is the repair complete?
4 Inspect the hydraulic lifters.
Is there evidence of hydraulic lifter bleed–down?
5 Clean, test and replace the lifters as necessary.
Is the repair complete?*
6 Inspect the crankshaft end clearance.
Is the clearance more than specified value?
7 Replace the crankshaft thrust bearing.
Is the repair complete?
8 Inspect the front main bearing clearance.
Is the clearance more than the specified value?
9 Replace the worn parts of the front main bearing.
Is the repair complete?
* When the engine is stopped, some valves will be open. Spring pressure against the lifters will tend to bleed the lifter down.
Attempts to repair this should be made only if the problem is consistent.
An engine that is only operated for short periods between start–ups may have lifter noise that lasts for a few minutes. This
is a normal condition.
Light Knock Hot
Action
Action
Value(s) Yes
Go to Step 2
Go to Step 3
Go to Step 1
45 NSm (33 lb– Go to Step 5
ft)
Go to Step 1
Go to Step 7
Go to Step 1
0.019–0.070 Go to Step 9
mm
(0.0007–0.0027
in.)
Go to Step 1
Value(s) Yes
Go to Step 2
Go to Step 4
Go to Step 1
Go to Step 5
Go to Step 1
0.01 mm Go to Step 7
(0.0039 in.)
Go to Step 1
2.0 DOHC Go to Step 9
0.015–0.040
mm
(0.00059–0.001
5 in.)
Go to Step 1
No
System OK
Go to Step 4
Go to Step 6
Go to Step 8
System OK
No
System OK
Go to Step 3
Go to Step 6
Go to Step 8
System OK
DAEWOO V–121 BL4