Daewoo Nubira User Manual page 416

1A – 8IGENERAL ENGINE INFORMATION
Step
1 Are dull thuds or knocks heard with every engine
revolution?
2 Check the oil pump pressure.
Is the oil pump pressure low?
3 Inspect the crankshaft end play.
Is there excessive crankshaft end play?
4 Inspect the crankshaft journals.
Are the crankshaft journals out–of–round?
5 Inspect the belt tension.
Is there excessive belt tension?
6 Inspect the crankshaft pulley.
Is the crankshaft pulley loose?
Step
1 Is a knock noise heard under all engine speeds?
2 Inspect the crankshaft connecting rod journal.
Is the crankshaft connecting rod journal worn?
3 Check the oil pump pressure.
Is the oil pump pressure low?
4 Inspect the crankshaft connecting rod journals.
Are the journals out–of–round?
5 Inspect the connecting rods.
Is there a misaligned connecting rod?
6 Inspect the connecting rod bolts.
Are the connecting rod bolts torqued properly?
NOISE DIAGNOSIS
Main Bearing Noise
Action
Connecting Rod Bearing Noise Symptom
Action
Value(s) Yes
Go to Step 2
Go toOil Pres-
sure Test
0.1 mm Go toCrank-
(0.0039 in.) shaft Replace-
ment Proce-
dure
0.004 mm Go toCrank-
(maximum) shaft Replace-
(0.0006 in.) ment Proce-
dure
Go toTiming
Belt Replace-
ment Proce-
dure
Go toCrank-
shaft Replace-
ment Proce-
dure
Value(s) Yes
Go to Step 2
Go toCrank-
shaft Replace-
ment Proce-
dure
Go toOil Pres-
sure Test
Go toCrank-
shaft Replace-
ment Proce-
dure
Go toPistons
and Rods Re-
placement Pro-
cedure
System OK
No
System OK
Go to Step 3
Go to Step 4
Go to Step 5
Go to Step 6
System OK
No
System OK
Go to Step 3
Go to Step 4
Go to Step 5
Go to Step 6
Go toPistons
and Rods Re-
placement Pro-
cedure
DAEWOO V–121 BL4