Engine Whine or Buzz Noise - keywords 3.1L 3.4L 3.8L alternator fuel generator L36 L67LG8 pressure regulator
| Subject: | Engine Whine or Buzz Noise |
| Models: | 2001-2005 Buick Century, LeSabre, Park Avenue, Regal |
| 2001 Chevrolet Lumina |
| 2001-2005 Chevrolet Impala. Monte Carlo |
| 2001-2005 Pontiac Grand Prix |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in the PI.
Condition/Concern:
Engine whine or buzz noise sounds like a generator type noise on 3.1L or 3.4L or 3.8L engines.
Recommendation/Instructions:
The condition the customers are describing is like a generator whine, moan, or like a fuel pump type noise, but it's coming from the front of the vehicle. It sounds more like a generator type noise than anything and you would swear it's the generator, but it can actually be the fuel regulator.
Before replacing any parts, be sure to use chassis ears placing a sensor on the fuel pressure regulator or unplug the fuel pressure regulator vacuum line.
If you disconnect the fuel pressure regulator and the noise goes away, then it could be either the fuel pressure regulator or a fuel line grounding out against a body panel or on the chassis.
Note: The generator will produce some normal noise during operation. This condition is caused by the normal magnetic pulses from the generator. Unplugging the generator will eliminate this noise due to the generator no longer producing current and no longer creating a magnetic field. If possible compare any generator noise or whine to a known good vehicle. If a known good vehicle has a similar noise, do not replace the generator.
Please follow this diagnosis 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.
