GM Service Manual Online
For 1990-2009 cars only

Step

Action

Values

Yes

No

1

Is there a heavy knock when the engine is hot and torque is applied?

--

Go to Step 2

System OK

2

Inspect the balancer and the pulley hub.

Is the balancer or the pulley hub broken?

--

Go to Step 3

Go to Step 4

3

Replace the broken balancer or the pulley hub.

Is the repair complete?

--

Go to Step 1

--

4

Inspect the torque converter bolts. Refer to Fastener Tightening Specifications.

Are the bolts tightened to specified value?

--

Go to Step 5

Go to Step 6

5

Tighten the torque converter bolts. Refer to Fastener Tightening Specifications.

Is the repair complete?

--

Go to Step 1

--

6

Inspect the accessory belts.

Are the belts too tight or nicked?

--

Go to Step 7

Go to Step 8

7

Replace and/or tension the belts to specifications, as necessary.

Is the repair complete?

--

Go to Step 1

--

8

Inspect the exhaust system.

Is the system grounded?

--

Go to Step 9

Go to Step 10

9

Reposition the system, as necessary.

Is the repair complete?

--

Go to Step 1

--

10

Inspect the flywheel.

Is the flywheel cracked?

--

Go to Step 11

Go to Step 12

11

Replace the flywheel.

Is the repair complete?

--

Go to Step 1

--

12

Inspect the main bearing clearance. Refer to Engine Mechanical Specifications.

Is the clearance more than the specified value?

--

Go to Step 13

Go to Step 14

13

Replace the main bearings, as necessary.

Is the repair complete?

--

Go to Step 1

--

14

Inspect the rod bearing clearance. Refer to Engine Mechanical Specifications.

Is the clearance more than the specified value?

--

Go to Step 15

System OK

15

Replace the rod bearings, as necessary.

Is the repair complete?

--

Go to Step 1

--