Diagnostic Aids
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2007 GMC Yukon XL, 2007 GMC Yukon, 2007 Chevrolet Tahoe, 2007 Chevrolet Suburban, and 2007 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
- Inspect the flexplate ring gear for damage or unusual wear.
- Shim the starter if applicable.
- In order to add pinion to ring gear clearance a full size shim must be used. Do not shim only one starter mounting bolt. There are 3 shims available in different shapes for clearance. All are 1 mm (0.039 in) thick.
Starter Motor Noise Diagnosis
| Step | Action | Yes | No |
|---|---|---|---|
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 | Start the engine. Does the starter operate normally? |
Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 |
| 3 | Start the engine while listening to the starter motor turn. Is there a loud "whoop", it may sound like a siren if the engine is revved while the starter is engaged after the engine starts, but while the starter is still held in the engaged position? |
Go to Step 6 | Go to Step 4 |
| 4 | Do you hear a "rumble", a "growl", or, in some cases, a "knock" as the starter is coasting down to a stop after starting the engine? | Go to Step 7 | Go to Step 5 |
| 5 | This is often diagnosed as a starter drive gear hang-in or a weak solenoid. When the engine is cranked, do you hear a high-pitched whine after the engine cranks and starts normally? |
Go to Step 6 | Go to Step 7 |
| 6 | Inspect the flexplate ring gear for the following:
Is the flexplate bent, or does it have damaged teeth? |
Go to Step 8 | Go to Step 9 |
| 7 |
|
Go to Step 9 | Go to Step 8 |
| 8 | Replace the flexplate. Refer to Automatic Transmission Flex Plate Replacement
. Did you complete the replacement? |
Go to Step 10 | - |
| 9 | Replace the starter motor. Refer to Starter Motor Replacement . Did you complete the replacement? |
Go to Step 10 | - |
| 10 | Operate the system in order to verify the repair. Did you correct the condition? |
System OK | Go to Step 3 |