96 Cobra motor Ticking for over 12k miles.

Discussion in '96-04 - 4V Specific' started by vnmsgt, Jun 23, 2014.

  1. vnmsgt

    vnmsgt Member

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    Bit of a long story but here goes. I have a 96 Cobra. Motor is stock except for IMRC deletes, 60# injectors and a Vortech V3. Almost 2 years ago the car overheated about month after I bought it and blew the head gaskets. I had the heads checked and shaved I believe is was .009" straight and put new gaskets and put motor back together. Since day one it has had a ticking. Thought maybe it was from an exhaust leak. Fixed that and still ticked. Used a stethescope and heard ticking from passenger side rear valve cover. replaced rockers and lifters. Ticking in cover gone but same tick was still heard when running. Put on a friends lift and again with a stethescope heard a loud ticking in bellhousing only. Removed trans and found friction clutch with 2 broken rivets and one rivet wedged between plate. Replaced clutch, flywheel, throwout and pilot bearing. Reinstalled, tick in tranny gone but original tick still there. Brought to 3 different shops and they cant find it. One shop replaced all the lifters on drivers said and some rockers saying old lifters were not pumping up and bad. Still ticks. One thing shops had in common was the said its coming from driver side rear of head/cylinder. You can hear it most behind the front driver wheel. I have taken this car to dyno days, dragstrip, across the state and beat on it and it will not break for over 12k miles now.

    Now for when you hear the noise.....You hear it at idle and every once in a while it completely disappears at idle and that maybe once a month and same thing when driving for a mile or 2 in traffic. When you put a load on the car, whether stopped and holding the brake like your gonna do a burnout, the noise goes away 100%. When you accelerate, hard or easy it goes away. You also hear when cruising and slow down just a little then try and hold your speed when you barely touch the gas. When you rev it in neutral it goes away but starts ticking as the rpms come back down close to idle like at 2k and under.

    Only thing I can think of after doing some digging is a wristpin. I have not taken if apart cause I dont want to rip into it and not find the problem. I have heard wristpin noise can last years and never have a problem but not sure of it.

    I have been a motorcycle tech for over 8 years and built plenty of sportbike motors and which these motors are similar just 2 sportbike motors back to back some car engines for myself and I understand all the dohc crap and tensioners etc but never have I heard of wristpin ticking. Whats everyones thoughts?

    I swear this car is sponsored by Timex, "Takes a licking and keeps on ticking!"
     
  2. vnmsgt

    vnmsgt Member

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    Still Ticking! Probably got another 1500 miles on it. I looked it on dates of pictures and its been like this for 17 months now and almost 14k miles.
     
  3. vnmsgt

    vnmsgt Member

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    Maybe one day it will break. Until then..... Wheels will be rolling!
     
  4. 96blak54

    96blak54 Legend

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    Ive always thought the infamous tick is a loose valve seat...idk
     
  5. vnmsgt

    vnmsgt Member

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    Could be. I have seen it alot on bikes but always found the problem after the seat came apart and motor messed up.
     
  6. 96blak54

    96blak54 Legend

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    And their is the offset piston pin. The orientation of that piston could be backwards causing piston slap....?
     
  7. RichV

    RichV Well-Known Member

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    How's your oil pressure?

    I had a Mitsubishi once that would have a lifter tick that I was chasing. It would tick worse with synthetic oil.

    Anyways, what about the timing chain/tensioners/guides? I know our 6.8 has a tick because they're worn.
     
  8. vnmsgt

    vnmsgt Member

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    Well it started ticking right after I did the head gaskets on it. All the guides were good and tensioners seemed ok. When brought it to Lamotta Performance they said the oil pressure was a little low I think around 28 psi at idle but as soon at you tapped the throttle it went to over 40. You only really here the ticking when cold, and once warmed up you hear it just about idle and when the rpm are coming back down to idle probably from 1800 down to idle rpm. Cruising and normal acceleration its gone. All the lifters were replaced as well as a couple cam followers.
     
  9. vnmsgt

    vnmsgt Member

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    When I did the head gaskets I never took the motor our and/or removed the pistons. Noise noise before then.