Engine grinding sound | FerrariChat
Buy

Engine grinding sound

Discussion in 'Technical Q&A' started by Dr.T348, Oct 2, 2006.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. Dr.T348

    Dr.T348 Formula 3

    Jan 8, 2004
    1,599
    Chicago NW Burbs
    Full Name:
    Richard T.
    #1 Dr.T348, Oct 2, 2006
    Yesterday midway through drive a new noise developed in my '94 348. At about 4500 rpm's and above it is making a metalic grinding sound. No noise at idle. More with full throttle. More pronounced with load on engine while driving, but also when reved in neutral. I do have a vacuum whistle in the small accuators on top of the engine for a while, but have not found a true leak.

    Any ideas or help?
     
  2. plugzit

    plugzit F1 Veteran
    Silver Subscribed

    Dec 1, 2004
    7,790
    Redondo Beach, CA
    Full Name:
    Bruce Bogart
    #2 plugzit, Oct 2, 2006
    Does it change depending on gear you're in or engine speed? (4500 in first the same or different from 4500 in 2nd or 3rd?) Or possibly road speed?
     
  3. Ken

    Ken F1 World Champ

    Oct 19, 2001
    16,078
    Arlington Heights IL
    Full Name:
    Kenneth
    #3 Ken, Oct 2, 2006
    Seems to me metallic grinding is a red light! Could be anything, but I'll take a wild guess and try a loose engine mount. But I'd say this sounds serious enough to forgo the guessing game and flatbed it to a mechanic!

    Ken
     
  4. tamf328

    tamf328 Formula Junior

    Mar 9, 2005
    477
    #4 tamf328, Oct 2, 2006
    may be you could rev it using your hand with the engine compartment open.
    might be able to tell where the noise is coming from.
    needless to say there are a lot of things going on in there. but you won't have to deal with the rolling parts.
    if your lucky it will just be something vibrating/rattling....
     
  5. Dr.T348

    Dr.T348 Formula 3

    Jan 8, 2004
    1,599
    Chicago NW Burbs
    Full Name:
    Richard T.
    #5 Dr.T348, Oct 2, 2006
    Thanks for the replies. It's in all gears and neutral. I can't tell where while I'm standing over it. Seems like top or induction, but at 4500-5000 it's hard to hear anyting.

    Off to the dealer in the morning to have it checked.
     
  6. plugzit

    plugzit F1 Veteran
    Silver Subscribed

    Dec 1, 2004
    7,790
    Redondo Beach, CA
    Full Name:
    Bruce Bogart
    #6 plugzit, Oct 2, 2006
    Probably a bearing on the front of the motor. There's not that much in the motor that will make a grinding sound, usually stuff in the motor taps or bangs. Tranny in neutral doesn't spin much. Good luck!
     
  7. Miltonian

    Miltonian F1 Veteran

    Dec 11, 2002
    5,966
    Milton, Wash.
    Full Name:
    Jeff B.
    #7 Miltonian, Oct 2, 2006
  8. No Doubt

    No Doubt Seven Time F1 World Champ

    May 21, 2005
    72,740
    Vegas+Alabama
    Full Name:
    Mr. Sideways
    #8 No Doubt, Oct 2, 2006

    I agree.

    Though it may be that you have a loud exhaust that covers up most of the noise. One test with the engine off that may be safe could be to jack up the rear in 5th gear and hand turn a wheel forward so as to turn the motor.

    You might be able to hear something rubbing/locked up that way without the exhaust noise. After that I'd probably remove the cam belt top access covers to see if the noise is coming from a belt guide rubbing on the belt.

    Other than that, I can't imagine that you could do much more than go the full engine out route, sorry.
     
  9. Dr.T348

    Dr.T348 Formula 3

    Jan 8, 2004
    1,599
    Chicago NW Burbs
    Full Name:
    Richard T.
    #9 Dr.T348, Oct 3, 2006
    It turned out the alternator dust cover bracket had broken and was rubbing. Nothing major, thank God.
     
  10. No Doubt

    No Doubt Seven Time F1 World Champ

    May 21, 2005
    72,740
    Vegas+Alabama
    Full Name:
    Mr. Sideways
    #10 No Doubt, Oct 3, 2006
    That's GREAT news!

    Cool.
     

Share This Page