odd knock
Cadillac
 

Cadillac Forums | Help Us Help You | Advertise | Cadillac Parts | Cadillac News | Cadillac Classifieds / (Old System)

Cadillac Technical Archive | Cadillac Dealers | Cadillac Reviews | Cadillac Dealer Reviews | Cadillac Vendors

CadillacForums.com is the premier Cadillac Forum on the internet. Registered Users do not see the above ads.
+ Reply to Thread
Results 1 to 6 of 6
5.0 and 5.7 Discussion, odd knock in Cadillac Engine Technical Discussion; When I start the car, it does not knock. When I put it into reverse, however, a low knock occurs. ...
  1. #1
    ReagansRollsRoyce is offline Cadillac Owners Fanatic
    Automobile(s): 1987 Cadillac Fleetwood Brougham
    Join Date
    Aug 2004
    Location
    Connecticut
    Posts
    183

    odd knock

    When I start the car, it does not knock. When I put it into reverse, however, a low knock occurs. It does not seem to occur from the engine, sounds more like it might be right below me. Almost sounds like it's in the car. Really doesnt do this when the car is put into D, maybe one.

    I was worried about the compression/cylinders at first but I tested the acceleration and it is normal, gas mileage normal, engine smooth as silk. This noise doesn't really seem to be coming from the engine itself.

    Any ideas? Motor mount? Or is it the bearing maybe and I'm in real trouble?

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    90Brougham350's Avatar
    90Brougham350 is offline Cadillac Owners Connoisseur
    Automobile(s): 94 FWB, 93 SDV, 94 FWB (sold), 90 Brougham (sold)
    Join Date
    Jan 2005
    Location
    River Falls, WI
    Age
    29
    Posts
    3,730

    Re: odd knock

    The fact it really only happens when you put it in Reverse may be a good clue there might be something up with the tranny. If it were a bearing or something of that nature though, you'd know it for sure.

  4. #3
    ReagansRollsRoyce is offline Cadillac Owners Fanatic
    Automobile(s): 1987 Cadillac Fleetwood Brougham
    Join Date
    Aug 2004
    Location
    Connecticut
    Posts
    183

    Re: odd knock

    Yeah I tried to catalog everything today, but I don't know:

    Shakes at idle when in Drive or Reverse (but not P) ie stopped at light with foot on service break

    When pressing down on accelerator from stop, "staggers" almost to get going but then goes perfeclty smoothly, accelerates fine, no knocking or slamming from engine:
    0-60 is 14 seconds which I think is the same as the original consumer reports road test back in '87 so I really doubt it's compression

    knock, if I could pin point it, seems to come either from right below me or right in back of the dashboard, goes like this

    release service break in D, press gas low *THUD* *stagger* *car shaky* then car goes forward normally
    shift from P to R, holding down service break, low *THUD* *THUD* *THUD* repeatedly *car shakey*

    any speed above, say, 5 MPH, no one would know there was a problem


    tranny isn't slipping between gears (or doesnt seem to be), still maybe only the low band is going


    I've never had a bearing go so I don't know what it sounds like...would it be knocking loudly at all speeds, or running really badly...

    my problem comes up only in parking lots and stop lights, never on the road.



    Frankly I'd be really relieved if it's the transmission, talking hundreds instead of thousands for a new engine

    Probably going to take it in to someone who can fix it on Thursday, I just wanted to see if anyone had ideas since I'm going to try not to be taken for a ride ("ohhh of course you need a new engine!!!")

  5. #4
    caddydream is offline Cadillac Owners Member
    Join Date
    Jan 2006
    Location
    Syracuse, NY
    Age
    57
    Posts
    88

    Re: odd knock

    Just a thought, the exhaust rapping against something?

  6. #5
    ReagansRollsRoyce is offline Cadillac Owners Fanatic
    Automobile(s): 1987 Cadillac Fleetwood Brougham
    Join Date
    Aug 2004
    Location
    Connecticut
    Posts
    183

    Re: odd knock

    Quote Originally Posted by caddydream
    Just a thought, the exhaust rapping against something?
    And so it was! Thanks. The exhaust rapped. And the shake: a vaccuum hose was lose.

    The compression is down some but that was unrelated, and I may have to address it soon.

  7. #6
    johndfw's Avatar
    johndfw is offline Cadillac Owners Fanatic
    Join Date
    Sep 2005
    Location
    Arlington Texas
    Age
    49
    Posts
    201

    Re: odd knock

    Hey
    Check your U joints.

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Bookmarks

Cadillac Posting Rules

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
Read about Lincoln | Buick | Kia Forte Forum
Need products for your Cadillac? Check out your options at the links below:

custom floor mats | Cadillac Chrome and Black Chrome Wheels | window tinting