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Thread: Knock knock... what's this?

  1. #1

    Knock knock... what's this?

    I will try my very to describe my issue, as engine noises are subject to the listener. My engine has a knock, it goes away after a bit, but when I start the engine it's pretty pronounced.

    I know the knock is coming from the 4th cylinder as I did the old spark plug wire pull test and it's very obvious. It is rhythmic to the sound of the engine.

    My questions... how far down the rabbit hole at I going? Piston? Rod? Duct tape? (kidding )

    I have a video locked and loaded if any one cares to take a listen.

    TIA.

  2. #2
    Yoda Geo Hahn's Avatar
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    Re: Knock knock... what's this?

    How is your oil pressure?

    A video (sound) will help - but what you describes sounds like a connecting rod, either the big end or the wrist.

  3. #3

    Re: Knock knock... what's this?

    Oil pressure is good. I have a video, but it's a bit too big for the site. I'd be happy to email it?

  4. #4

    Re: Knock knock... what's this?

    Here is a YouTube link to my issue....

    https://youtu.be/xgi8RZ6x6qY

    hopefully y'all have good news for me!

  5. #5
    Jedi Knight
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    Re: Knock knock... what's this?

    I can't think of anything easy so the good news is that it is relatively easy to pull off the head and the pan to have a look, although not something you want to do. You'll start with the valve train and check the pushrods, rockers and lifters but my guess is that it's in the bottom end. Don't forget to bolt down the liner when you push the piston out.
    Tom
    1960 TR3A TS73117 (under restoration year 6, owned since 1964)
    1959 TR3A TS58023 (in case I never finish the one above)
    1969 Triumph Herald 13/60 (a whim)
    1973 Buick Apollo (was Dad's car)
    1992 BMW325IC (fun to drive)

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    Yoda TR4nut's Avatar
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    Re: Knock knock... what's this?

    Well listening to a video may not be reliable but that sound very valve train related to me. Very sharp sound, not deep and muffled. Anyway worth pulling the valve cover I think to have a look.
    Randy
    70 TR6 - running
    59 TR3A - slumbering
    64 TR4 - got another one!

  7. #7
    Jedi Warrior
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    Re: Knock knock... what's this?

    Sounds like a much louder version of the noise I had in my engine. Mine was sorta intermittent. I kept wondering what it was. I eventually pulled the pan and I had a connecting rod bearing problem that slightly scored the crankshaft. Ended up having to rebuild the engine since the crank was scored. I highly recommend that you do not run the engine anymore and pull the sump pan and thoroughly check all of the connecting rod bearings. Maybe you can get by with just putting in new rod bearings.
    Bob

  8. #8
    Obi Wan
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    Re: Knock knock... what's this?

    what TuffTR250 said========= and at the end of the hall, it depends on how much money!!!

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    Yoda CJD's Avatar
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    Re: Knock knock... what's this?

    Valves don't really care whether they are under ignition load or not. So it's not likely valve train, or removing the ignition would not make a difference.

    That leaves Rod bearings and piston slap. The interesting thing is that normally those noises happen over time and get louder slowly. That is unless something suddenly happened, like losing oil pressure that led to a spun bearing.

    Edit: It is hard to hear it well in a video...but a bad exhaust gasket, head gasket, or loose spark plug can do what you hear too. The head and spark plug can be checked with a compression check. The exhaust gasket by using a tube to your ear to tell where it's coming from.

    Bottom end woes can often be pinpointed by toucing the handle of a long screw driver to your forehead and touching the tip to the block area in question.
    John

    1955 TR2

  10. #10

    Re: Knock knock... what's this?

    Well I can cross a couple of those off the list, the exhaust is tight and so is the spark plug. I could check the head gasket, but I'm leaning towards a bottom end problem. This noise has been going on since I've heard the car running and don't know the history before that. I have only put about 60 miles on since I've had it running and the noise usually goes away after it warms up a bit.
    *1959 TR3A
    *1951 Chevy Fleetline Deluxe
    *1986 GMC Sierra Classic

  11. #11
    Obi Wan
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    Re: Knock knock... what's this?

    I did listen to the noisy, and it sounds like the bottom end rod bearing than can be hillbilly fixed cheap and not running the motor is good idea ; it will not cause any more damage, but the cracking of the spark plug wire coming on and off made it difficult to be sure, but a definite maybe on a rod bearing.

    But However and Again, I have detected knocking noises by setting the valves down from .10 to .04 maybe even . 02 there needs to something for gap a and the hot and cold deal----- is trick when you are playing around. Triumphs can have knocking valve trains and run fine as long as things are not tooo tight. But you really want the motor set at nice clean .10 ---some of the problem variables are dished lifts and dished rocker arms that make setting the valves difficult because the feeler gauge cannot read the dish--- plus there are bent cams and a combination of noises because of wear in a combination of places. So if you know your motor and kinda don’t care set those valves extremely; low and run it for second. -

  12. #12
    Obi Wan
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    Re: Knock knock... what's this?

    The noise going away is usually a good thing, but it still probably is bad, I have bad motors when the oil gets hot really do the knocking==== Is the knock deep and hollow and kind have a double sound if so bad news

  13. #13

    Re: Knock knock... what's this?

    The knocking goes away after about 5 minutes of being warm. I am going to pop the pan off and check to see what's going on. I'm hoping because it does go away, the issue isn't as bad as suspected - my garage is tiny and pulling the engine might take up the last bit of space I have to work. :/
    *1959 TR3A
    *1951 Chevy Fleetline Deluxe
    *1986 GMC Sierra Classic

  14. #14
    Jedi Knight
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    Re: Knock knock... what's this?

    Quote Originally Posted by HighAltitudeTR3 View Post
    The knocking goes away after about 5 minutes of being warm. I am going to pop the pan off and check to see what's going on. I'm hoping because it does go away, the issue isn't as bad as suspected - my garage is tiny and pulling the engine might take up the last bit of space I have to work. :/
    Good place to start, the problem just might be obvious at the big end. If nothing found you'll need to get the piston out and that requires pulling the head. If it's the piston or wrist pin, you might not need to remove the engine. Also might suggest a compression test first and if you do pull the head, check all the push rods, lifters and rockers etc.
    Tom
    Tom
    1960 TR3A TS73117 (under restoration year 6, owned since 1964)
    1959 TR3A TS58023 (in case I never finish the one above)
    1969 Triumph Herald 13/60 (a whim)
    1973 Buick Apollo (was Dad's car)
    1992 BMW325IC (fun to drive)

  15. #15
    Yoda Geo Hahn's Avatar
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    Re: Knock knock... what's this?

    Nothing to add - here's hoping you find a badly worn rod bearing but no crank damage.

  16. #16
    Obi Wan
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    Re: Knock knock... what's this?

    Yes Tom is correct you can drop the pan and pull the head then the pull the bad one out the top, and heck it might be good another 50K if it is wrist pin or did not score the crank too bad

  17. #17
    Yoda CJD's Avatar
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    Re: Knock knock... what's this?

    Quote Originally Posted by HighAltitudeTR3 View Post
    This noise has been going on since I've heard the car running and don't know the history before that. I have only put about 60 miles on since I've had it running and the noise usually goes away after it warms up a bit.
    Given that info...my best guess is a spun bearing shell. Not likely that only one piston has worn that much more than the others to cause slap. The pin end is possible...but less likely than a spun bearing.

    You're car has proven to be quite the project!

    Edit:

    If you don't know the history, then I would give the full oil system a going over. Including the plugs in the crankshaft and the holes through the connecting rods. A single bad rod bearing is a sign that something is off with lubrication. Of course...a Bozo mechanic could have assembled the engine and forgot to tighten the rod bolts.

    If it's loose bolts, the crank may be fine and problem solved. If it is spun bearing, the crank will have to come out...it will not be good on the #4 journal. By definition, a bearing spins because the crank bearing surface has seized, and that always leaves the crank badly heat scored.

    If the bearing spun, and the bolts were torqued on the rod, then you really should pull the crank and check the oil plugs throughout the engine. Otherwise it very well may happen again.
    John

    1955 TR2

  18. #18

    Re: Knock knock... what's this?

    IMG_9574.jpg

    The cam cam looks good (that's an oil smudge) and the bearings look ok as well, but I'm not sure the tolerances. Is there anything else I should check while I'm here?
    *1959 TR3A
    *1951 Chevy Fleetline Deluxe
    *1986 GMC Sierra Classic

  19. #19
    Yoda CJD's Avatar
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    Re: Knock knock... what's this?

    That looks good. Were the bolts tight? What size bearings were installed? It should be stamped on the back.
    John

    1955 TR2

  20. #20

    Re: Knock knock... what's this?

    The bolts were tight (breaker bar tight). The bearings have stamps, but not a size... is there a cross reference?
    *1959 TR3A
    *1951 Chevy Fleetline Deluxe
    *1986 GMC Sierra Classic

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