Page 1 of 16 12311 ... LastLast
Results 1 to 10 of 160

Thread: mysterious rattle

  1. #1
    Join Date
    Jul 2014
    Posts
    207

    Default mysterious rattle

    As I noted on my fuel pump thread, what was a faint intermitant rattle before I left on a business trip has become an alarmingly loud rattle. I've uploaded a short video to youtube here (https://youtu.be/gsbGi-AGlk0).
    I don't have any idea at all of what is causing it. A wild guess is that a belt tensioner is loose...??? I removed the belt cover from the rear bank to give a quick look, but of course I can't observe it running since the Xdi triger wheel sensor is mounted on the cover I removed. I'll get it to TDC and lock the cams before I start taking things apart. In the meantime, if anyone has any ideas... Any ideas will be much appreciated.
    Thank you as always for your help & support.

  2. #2
    Join Date
    Sep 2009
    Location
    In the big house
    Posts
    7,068

    Default

    Short of a blown out exhaust gasket and/or sniffer tube bung, it should be obvious. Disassembly required.
    Sarasota Italian Garage, LLC
    "The Fluent in Ferrari Guys" celebrating 37 years of service excellence
    **An independent facility with no affiliation with Ferrari SpA**
    Sarasota, FL
    www.fluentinferrari.com

  3. #3
    Join Date
    Jul 2014
    Posts
    207

    Default

    Thanks for chiming in Radioman.
    I must have jinxed myself remarking how good she's been running earlier. It really has been running great since I adjusted the valves, synchronized the carbs and installed the Xdi. I'm hoping I don't have to pull the engine, but she does have a lot of miles on her. Not how I was planning to spend Spring, but at least the garage is warm enough to work in... I just wish I knew what I was doing... Oh well, another learning experience - wish me luck!

    Thank you again!

  4. #4
    Join Date
    Jun 2007
    Location
    Massachusetts
    Posts
    13,328

    Default

    One notorious place for a rattle in the 308 is the A/C hoses banging against the place where they go into the bodywork from the compressing. The factory "fixed" it by wrapping a little foam around them and stuffing it inside that opening. Many people have removed that foam for some reason when working on the timing belts (and moving the AC compressor) then ended up with a loud rattle that sounds horrendous, but is actually harmless.
    Birdman308 for parts and tutorials!

  5. #5
    Join Date
    Jul 2014
    Posts
    207

    Default

    Thanks for the tip Birdman.
    I'm going to put the belt cover back on, so the Xdi works; and spend some more time trying to isolate the rattle before I take too much apart. I'm afraid Radioman's right about needing to dissemble; I just want to keep disassembling to a minimum.

    Thanks again guys; I sincerely appreciate the support.

  6. #6
    Join Date
    Jul 2014
    Posts
    207

    Default

    I put the belt cover back on to run the engine, and look for the rattle; and I think I found it. I THINK it's the cam belt lower drive pully # 104914 (Puleggia conduttrice) #28 on TAV 8. I've uploaded another video to youtube here (https://youtu.be/IBN-4iWKEjw); see how the cam belt lower drive pully jumps around? (shaky hands don't help). That jumping around could be normal for all I know, but I noticed that the rattle conincides with the dancing dimple in the pully shaft. I would expect some jumping of the tensioner, but not the drive pully...??? Anyway, it looks suspicious to me.

    I seem to remember running accross a tutorial on how to replace those. IIRC it involves drilling a hole to pull the old ones out..... I'll start my search for that tutorial now. In the meantime, If anyone has any remarks or suggestions, I'm all ears.
    Attached Images Attached Images
    Attached Files Attached Files

  7. #7
    Join Date
    Sep 2009
    Location
    In the big house
    Posts
    7,068

    Default

    Video link isn't working... Regardless, there should be zero movement on the lower drive pulleys. The design/support improved as the cars evolved. How long ago did you do belts? As I said earlier, disassembly required.
    Sarasota Italian Garage, LLC
    "The Fluent in Ferrari Guys" celebrating 37 years of service excellence
    **An independent facility with no affiliation with Ferrari SpA**
    Sarasota, FL
    www.fluentinferrari.com

  8. #8
    Join Date
    Jul 2014
    Posts
    207

    Default

    Radioman:
    Thank you so much for your quick response. link: https://youtu.be/IBN-4iWKEjw should work...???
    Last did belts August 2014, but I didn't touch the drive pulleys (didn't seem to need at the time). I did adjust valves, replace cam seals (dropped a nut down an oil channel) changed cam belts and tensioner bearings. I was planning on doing next belt change next year (5-year intervals), but I guess I'll need to move that up.

    I didn't doubt you for a minute that disassembly would be required..... how difficult is it to change the drive pulley bearings while doing the belts? Will email you re parts.

    Thank you again!!!

  9. #9
    Join Date
    Sep 2009
    Location
    In the big house
    Posts
    7,068

    Default

    I saw the video. There's little doubt that you had some sort of failure with the lower drive pulley/ bearing. The big question is just how much damage has been done. The outer bearing can be done in situ. Lots of work involved....Anything more, the engine is coming out and being separated from the transaxle.
    Sarasota Italian Garage, LLC
    "The Fluent in Ferrari Guys" celebrating 37 years of service excellence
    **An independent facility with no affiliation with Ferrari SpA**
    Sarasota, FL
    www.fluentinferrari.com

  10. #10
    Join Date
    Jul 2014
    Posts
    207

    Default

    Thanks for the quick reply Radioman.
    I'll keep my fingers crossed for an engine-in solution (plan A). The biggest problem if the engine does have to come out (plan B) is that there is little limit (except resources) as to what I'll want to do while it's out. I suppose at least a standard rebuild with some improvements..... Wait! better not get started; i could probably buy a 360 for less.... (plan C?)

    Thanks again!
    email sent

Page 1 of 16 12311 ... LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •