WTF is this noise, and why is it happening??

Discussion in 'Classic Mustang Specific Tech' started by woodsnake, Dec 16, 2011.

  1. I wanted to get it done today, but as I was gathering my tools and reorganizing, I managed to douse myself in type F...REst of the day domestic, tomorrow, valve train inspection!
    I think a good visual inspection will reveal all...
  2. Is there a baffle under either or both of the valve cover holes? If the valve cover rail height is different on the Edel heads than on the previous heads the rockers may now be contacting the baffle(s).
  3. Well, I pulled the valve covers off, and found no surprises. There were a couple of rockers that were slightly loose, but nothing that had slipped off, or was otherwise out of order. No signs of contact that wasn't supposed to be. I have had a couple of folks suggest that by replacing the stock duraspark springs with the light weight spring kit, that I was getting to much vacuum advance. So, I capped off the distributor and the carb, and still had about the same amount of noise.
    I am very angry at this car!
  4. Did you run it with the covers off?
  5. No, I ran it with the vacuum advance disconnected, and tried to adjust the timing by ear, to see what would happen. Changing the initial timing did not make the noise go away, but did impact the severity. I am convinced now that the springs I put in are providing too much advance, and that is what is causing the popping back through the carb,.
  6. Hmmm... so if you're getting predetonation is there an electronic alternative to the vacuum setup?
  7. There are aftermarket distributors, but I am going to swap in another duraspark with the stock springs, and see if that cures it.
  8. A sticking valve will make it backfire through the carb...
  9. I think it's the cam. I swapped in a different distributor with the stock springs, and ran it again. No real change in noise..Pulled the dipstick right after I shut it off, and just the tiniest hint of glimmer of shiny **** was in the oil...I can't believe it.
    My responsible bone just took a break, and I'm going to try and drown away my anger...
  10. Yes, could be a worn lobe. Mine made a sound similar to yours with a lot more popping. I personally trashed a new Edelbrock cam in less than 90 miles. I called myself breaking it in according to Edelbrock break-in procedures only I did not use high zinc break-in oil. Edelbrock warranted the cam but it was still a hassle to re-do. Inexperienced builders take note: Oil off the shelf in the last 5 years or so ago does not contain zinc which is required for a new flat tappet cam installation. I learned the hard way.
  11. I am still sitting here in Kuwait, but the thought occurred to me, that MAYBE it has something to do with the 'steam holes' we drilled in the block? I think we only drilled out one hole, on the front of each bank. One by #1, and one by #5.. Any hope for a steam hole related noise?
  12. Did you also check the fuel pump? It wouldn't be the first time I heard a tapping on the driver's side that wasn't a lifter.
  13. fuel pump is new, also. I built the motor when I was going to school in 06, so everything is new or rebuilt. But since I am an AMC frequent flier, lots of time goes by in between bouts of work on it. I really need to just stop worrying about it, as I have at lest 3 more months here before I will be home. I'm now leaning back to the hanging valve though, and hoping that one more time around the poly locks will restore my hot rod to somewhat daily driver status. I will post the solution, when I figure it out!
  14. Take of the valve cover and fire it up if the noise persists I'm betting on a sticky valve.
    Let us know!
  15. I've seen people take the older stamped valve covers they don't need any more and cut out a section of the top so they can adjust the valves easily. If you have a valve cover you are willing to sacrifice then you could try that out.
  16. Actually, I do have a set that I cut up already...
  17. check the timing chain it may have stretched and could be slapping and sounding like the tick of lifters. and also if the heads have been machine and had a valve job. they could of had a worn out tool and a valve may not seat right and may cause some noise back up through the carb