For 1990-2009 cars only
High Pitch Screetch Noise From The Engine Cold - keywords belt drive leak vacuum whistle
| Subject: | High Pitch Screech Noise From Engine Cold |
| Models: | 2007 Chevrolet Silverado |
| 2007 GMC Sierra |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Some owners may comment of a very loud high pitched "screech" noise that occurs in temperatures less than 15°F (-9°C) with the engine operating between 1400 and 2100 rpm. This noise may sound like it is coming from the drive accessory belt or an engine vacuum leak. The noise typically goes away after 10 to 15 miles (16 to 24 km) of driving. This noise may be coming from the generator.
Recommendation/Instructions:
If the noise is isolated to the generator replace it.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
