» » »

Chevrolet Q&A

Ask Your Question

1995 Chevrolet Lumina Question: Chevy Lumina-Sedan 3.1L, RPM NEEDLE OSCILLATING SLIGHTLY UP AND DOWN, at Idling.



carzen, 3.1L V6, Moorpark, CA, August 01, 2013, 16:51

I recently notice that when my GM Chevy Lumina-Sedan LS 3.1L is idling, its RPM guage needle oscillates up and down slightly and not too fast like vibrating. Also, there is a humming noise from the engine compartment.

I want to fix this problem before it gets worse. Your advice will be appreciated.

1 Answer
Flag This
  • Answer #1

    August 03, 2013, 05:56

    Does the humming come and go as well and at the same time as the Idle changes? How much RPM variation is there?

    Flag This
  • Reply

    carzen, August 05, 2013, 16:26

    Thanks for your reply! Yes the humming noise come and go as well, it was around the alternator.
    RPM was about 900-800, which is about as usual. I do not believe that my engine has vacuum leak, since I just replaced the lower/upper manifold gaskets and RTV sealed them properly, without any more oil/coolant leaks!!

    Flag This