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Hearing Strange Noise From Engine Compartment

Discussion in 'Early CJ5 and CJ6 Tech' started by mickeykelley, Oct 28, 2018.

  1. Mar 11, 2019
    mickeykelley

    mickeykelley Well-Known Member

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    So I started it up over the weekend and it ran fine except for the noise around the 2,000 mark. So I know it still has to go back to him. But I'm trying to figure out the running rough and dying the other day. I do know it was running a little high on the temperature gauge after driving at 45 for an extended period and it was 85 outside that day. It normally runs with the needle just barely above the mid point but it got up about the mid mark between middle and high so about the 3/4 mark. Prior to rebuild, I drove it all the time at 45 and the temp didn't go up there. So I'm wondering if it wasn't vapor locking. I've never really experienced that so not sure what to expect.

    But I did get more miles on the engine and the sound is definately still there so it doesn't change th fact of having to pull the motor again.m
     
  2. Mar 11, 2019
    Glenn

    Glenn Kinda grumpy old man Staff Member

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    I've never experienced vapor lock either but I would think it would be a total no fuel flow situation and would have to be pretty darn hot for that to happen. As far as the temperature rise how about fan belt tension? Did you check the radiator level?
     
  3. Mar 11, 2019
    Keys5a

    Keys5a Sponsor

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    That noise from 2000 rpm-up is almost certainly big end rod bearings. There is likely either an oil pressure issue, or crank or big ends out of spec.
    -Donny
     
  4. Mar 11, 2019
    PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    A new rebuild will be "tight" and produce more heat at first... maybe?

    And/or, the resistance in the electrical connection to the sensor may be different now, changing the gauge reading?
     
  5. Mar 11, 2019
    Chilly

    Chilly Active Member

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    Pinging will make a sound like tiny little gremlins (critter, not car) hitting hammers in your engine. Also generate a lot of heat. And if caused from a lean condition it will run REALLY hot. But too much advance or too much cylinder pressure can cause that, too.
     
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  6. Mar 11, 2019
    Keys5a

    Keys5a Sponsor

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    I totally agree with this statement regarding pinging, but an F134 has such low compression, like 7.2, that is is really hard to get one to ping (pre-detonate). If the timing was advanced so far as to produce pinging, it would likely not start due to the way advanced spark. Same with the lean condition, it would likely not start.
    -Donny
     
  7. Mar 12, 2019
    mickeykelley

    mickeykelley Well-Known Member

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    When I take it to him, I'm going to push the question if the rods were truly checks for specs and what was does originally on the crank.

    I checked the fluid level first thing and all normal. The fan belt fine too based on tension I have put on belts forever. I remember driving it last summer when it was well over 85 and for long local stretches at the 45 mph. When I'm talking long stretches, I'm really only talking about 5-7 miles continuos at the speed, so that's really nothing.


    I don't think it's that since Sunday's drive it was normal, but I only spent 1.5 miles at the higher rpm due to the noise.

    The carb and timing have not changed but I'll check them and pull a plug. My sense is if anything it may be a bit rich from the smell of exhaust.
     
  8. Mar 13, 2019
    NCRenII

    NCRenII yellow fever

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    Bore taper, piston size and wrist pins, as well as rod straightness should also be checked while he's in there.
    One can dx a knock or noise and isolate top or bottom by the "sonud". Deep, or metallic, and top end or bottom end can be determined with a stethescope (or my preferred broom stick). Deep knock definitely rods or crank, metallic piston or wrist pin.
    Again I did not read the entire thread, water in fuel, dislodged carbon, etc. I think you're beyone that with the builder involved and I stray to recriprocating system. Then there's the entire issue of can and valve train.
    It's nice the builder is backing his work. The quality of the build will appear with the cause.
     
  9. Mar 24, 2019
    mickeykelley

    mickeykelley Well-Known Member

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    What a pain in butt. Got everything disconnected and/or removed so all I've got to do is yank it out tomorrow and drop it off. He damn sure better make sure he gets it figured out. At least I get to head to the mountains and get some late skiing in while he's doing it. Rear main and/or pan leaked oil on the bottom and its a greasy mess again. Suggestions or secrets I could give him on making sure they don't leak while he back in there. I know about not over tightening the pan. Others? Although he should know them all.
     
  10. Apr 11, 2019
    mickeykelley

    mickeykelley Well-Known Member

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    Back from skiing and picked the engine up today. He pulled it all apart and blew out all passages, etc and didn't find any junk. The new bearings he put in were toast again and indicating contaminated scratches. Went from bad to worse as he worked from front to rear. He took the crank down 10 and said rods look fine. He didn't find anything else and has no idea on where or what. He did say to let him know any cost I incurred so he could reimburse me as he wanted to make it all good. So I'll start putting it back in and see how it goes.
     
  11. Apr 11, 2019
    Glenn

    Glenn Kinda grumpy old man Staff Member

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    Well, let's hope this time fixes it.
     
  12. Apr 12, 2019
    47v6

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    What caused the bearings to fail? Lack of oil pressure? Improper sizing?
     
  13. Apr 12, 2019
    mickeykelley

    mickeykelley Well-Known Member

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    I'll post some pics later today when get time but he showed me pics in book and it matches up to contaminate.
     
  14. Apr 12, 2019
    Glenn

    Glenn Kinda grumpy old man Staff Member

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    Only thing that makes sense would be that whatever was originally in there finally worked it's way through. Apparently he thought he got it all after the first time.
     
  15. Apr 12, 2019
    mickeykelley

    mickeykelley Well-Known Member

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    I certainly hope so. He said he went through the every passage way and found nothing. Now to find time to stick it back in.
     
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  16. Apr 13, 2019
    mickeykelley

    mickeykelley Well-Known Member

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    Here the pics. #4 was the worst one. I'm assuming oil flow start at the back?
    image.jpg image.jpg
     
  17. Apr 13, 2019
    Chilly

    Chilly Active Member

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    I work on engines with pistons larger than #10 cans. Bearing failure at bearings at the end of the oiling circuit sometimes caused by debris ingestion. In this case maybe break-in debris is causing filter to bypass, sending trash to the last bearing? It could reach any bearing, but the oil will carry it along. Debris that gets past other bearing passages will loiter around the last bearing until it eventually passes through.

    Not for certain, but this is my experience with big engines.
     
  18. May 23, 2019
    mickeykelley

    mickeykelley Well-Known Member

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    Finally got engine back in Willie yesterday and fired him up. He sounded fine but again time will tell.
     
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  19. May 23, 2019
    Glenn

    Glenn Kinda grumpy old man Staff Member

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    :waiting: :)
     
  20. May 23, 2019
    mickeykelley

    mickeykelley Well-Known Member

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    Had a few unplanned delays. Life...
     
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