GM Service Manual Online
For 1990-2009 cars only

Step

Action

Values

Yes

No

1

Is the oil pressure warning lamp on?

--

Go to Step 2

System OK

2

Check the oil level in the crankcase.

Is the oil level low?

--

Go to Step 3

Go to Step 4

3

Add oil so that the oil level is up to the full mark on the indicator.

Is the repair complete?

--

Go to Step 1

--

4

Check the idle speed.

Is the idle speed below the specified value ?

840 ± 20 RPM

Go to Step 5

Go to Step 6

5

Increase the idle speed.

Is the speed increased?

--

Go to Step 1

--

6

Inspect the oil pressure switch.

Is the oil pressure switch incorrect or malfunctioning?

--

Go to Step 7

Go to Step 8

7

Install a new oil pressure switch.

Is the repair complete?

--

Go to Step 1

--

8

Inspect the oil pressure gage.

Is the oil pressure gage incorrect or malfunctioning?

--

Go to Step 9

Go to Step 10

9

Install a new oil pressure gage.

Is the repair complete?

--

Go to Step 1

--

10

Inspect the engine oil.

Is the engine oil in the crankcase diluted or of the improper viscosity?

--

Go to Step 11

Go to Step 12

11

Install new engine oil of the proper viscosity for the expected temperatures.

Is the repair complete?

--

Go to Step 1

--

12

Inspect the oil pump.

Is the pump worn or dirty?

--

Go to Step 13

Go to Step 14

13

Replace the oil pump.

Is the repair complete?

--

Go to Step 1

--

14

Inspect the oil filter.

Is the oil filter plugged?

-

Go to Step 15

Go to Step 16

15

Install a new oil filter.

Is the repair complete?

--

Go to Step 1

--

16

Inspect the oil pickup screen.

Is the oil pickup screen loose or plugged?

--

Go to Step 17

Go to Step 18

17

Tighten or replace the oil pickup screen, as necessary.

Is the repair complete?

--

Go to Step 1

--

18

Inspect the oil pickup tube.

Are there any holes in the oil pickup tube?

--

Go to Step 19

Go to Step 20

19

Replace the oil pickup tube.

Is the repair complete?

--

Go to Step 1

--

20

Inspect the bearing clearances.

Are the bearing clearances more than the specified values?

0.024-0.042 mm (0.00094-0.00115 in)

Go to Step 21

Go to Step 22

21

Replace the bearing, if necessary.

Is the repair complete?

--

Go to Step 1

--

22

Inspect the oil galleries.

Are the oil galleries cracked, porous, or plugged?

--

Go to Step 23

Go to Step 24

23

Repair or replace the engine block. Is the repair complete?

--

Go to Step 1

--

24

Inspect the gallery plugs.

Are any of the gallery plugs missing or installed improperly?

--

Go to Step 25

Go to Step 26

25

Install the plugs or repair, as necessary.

Is the repair complete?

--

Go to Step 1

--

26

Inspect the camshaft.

Is the camshaft worn or is there evidence of poor machining?

--

Go to Step 27

System OK

27

Replace the camshaft.

Is the repair complete?

--

Go to Step 1

--