Rattle and clatter

Discussion in 'Honda K-Series' started by Whisker Version, Friday 15th Mar, 2019 at 8:48pm.

  1. Whisker Version Club Member ★ ☆ ☆ ☆ ☆

    United Kingdom Bristol
    42
    15
    Hello folks, I'm seeking your opinions on this noise: https://instaud.io/3lvD
    I've had a thread going here, and it was suggested I'd get more visibility by posting in the engine forum.
    It only happens with a cold engine, and goes away (to my ears) within half a minute to a minute, so it is temperature related in some way.
    The noise has become a bit embarrassing.
    To me, it doesn't seem to change frequency with engine speed, and is particularly bad at around 1800rpm.
    I can hear it from the cab better than from top of the engine bay, where there are all sorts of other noises.
    I've slipped the aux belt off, and the noise remains.
    The local garage reckon it might be piston slap or a little end bearing failure, and the next step would be an engine tear-down, which would probably be as expensive as as engine replacement, even if I could simply replace it (JDM).
    Car has purportedly done 72k miles.
    Cheers.
     
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  2. SpeedyGee Club Manager Club Staff

    England Speedy Birmingham
    17,106
    7,536
    5
    That sounds nasty, I wouldn't rev it unnecessarily.

    Kinda sounds like a valve train sound. Get a leak down test done, see if that reveals any leaking valves. Could also be rattling from chain area but sounds little heavy for that.

    It could be piston slap or a bearing noise and yes that would need a strip down.
     
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  3. SpeedyGee Club Manager Club Staff

    England Speedy Birmingham
    17,106
    7,536
    5
    Actually listening to it again, it does sound more like a piston slap sound.
     
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  4. Zebster Club Veteran ★ ★ ★ ★ ★

    Could even be a big end.

    Try starting it with a plug lead off, one at a time, to see if you can narrow it down to one cylinder?
     
  5. Whisker Version Club Member ★ ☆ ☆ ☆ ☆

    United Kingdom Bristol
    42
    15
    A couple of questions before I do this: if I disconnect a spark plug, won't that introduce a confusing new vibration and noise? And could it destroy the cat? I thought unburnt fuel could detonate in the cat and break it up; you might say that is the least of my concerns at the moment!
    One thing I've come to realise is "I am not special" so have other unmodded K20A owners experienced piston slap or bearing failure at relatively low miles?
    Has anyone got a HowTo for setting the valve clearances? There isn't much room in the engine bay, but I might as well have a go myself since the alternative deep-dive investigations are going to be very expensive.
     
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  6. jd1959 Top Contributor ★ ★ ★ ★ ☆

    Ireland Zack Kilkenny
    536
    314
    If done for an extended period of time yes can cause big expensive problems but for 10 seconds or so while you determine that it is/isn't the correct cylinder no problem. It will put up a check engine light and store a code though.

    There are a few guides here and a couple of youtube videos for k series but I found helpful for a general idea.

    On the Stepwgn to get the rocker cover out is a bit of a wiggle and the exhaust valves are mainly set by feel rather than sight but you can place a mirror on the bulkhead to help you see due to engine location being half buried. Remove the power steering hose from the pump and the bracket from the vacuum line going to the brake booster to get a bit of clearance. A stubby flat head screwdriver and a short 10mm box wrench also help with clearance issues I find the long feeler gauges way too hard to use on the exhaust on this car and wind up using the short ones. I usually turn the engine via the power steering pump but be sure to note the direction it runs you don't want to turn the engine backward. The exhaust I set at .012 and the intake at .009 and have found it to run well, they are a bit loose and rattle when cold but I'm running lpg and really don't want them too tight.

    Main thing is to take your time and double and triple check the work before you button it up. With repetition I'm at about a half hour for a valve adjustment job but being your first time plan a few hours.

    This is a great video for cheap and cheerful checking of rod knock might as well while the plugs are out if you can get a screwdriver the right length to get in with the above mentioned clearance issues.

    The cheap ebay bluetooth obd dongles and the free torque app work fine with the RG1 for clearing codes and reading some of the live data, given the trouble shooting your planning to do you will set the check engine light so might be worth the fiver to get.

    Good luck I have my fingers crossed that you find something simple causing the problem and not an engine in need of replacement!!

    Zack
     
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  7. Whisker Version Club Member ★ ☆ ☆ ☆ ☆

    United Kingdom Bristol
    42
    15
    Those vids are good. Thank you. I don't suppose the Honda valve adjustment tool would be any use, because it wouldn't fit in the space available?
    I'm bothered that I'll wreck my back by leaning over for so long...could do with a bed or hammock to lie on. Without seeing it first-hand, I thought the use of sealant on just parts of the rubber gasket on the rocker cover was a bit odd. You would design for one or the other?

    Has anyone come across Combustion Chamber Deposit Interference (CCDI)? Apparently, it sounds like piston slap as the piston+carbon hit the combustion chamber at cold. Being on LPG, I'd have thought I'd have less carbon than usual, but who knows.
     
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  8. jd1959 Top Contributor ★ ★ ★ ★ ☆

    Ireland Zack Kilkenny
    536
    314
    In this case no there wouldn't be enough clearance between the exhaust valves and the structure at the base of the windscreen.

    In all honesty even getting the plugs out requires putting the socket in, then connecting the extension and finally the ratchet as you feed it down the well. If you have a length of vacuum line laying around that fits the top of the plugs it makes getting them in and out far easier once loose.

    Don't know if its odd but I have only ever put a pea size DOT at those points and haven't had it leak yet even reusing the gasket if it hasn't gone brittle. With the clearance issues we have if you put more goo on the gasket you would wind up with it covering the valve train as you tried to maneuver the cover back into place.

    Take lots of breaks the far left exhaust bank has been is the worst for me to get to, so I've learned to start there before the muscles in my back start complaining.

    Haven't heard of it but you'll have a better idea of what the combustion chamber is like once you can see the end of the plugs. Just getting the rocker cover off and adjusting valves will give you a good idea as the condition of the upper half of the engine. Don't forget to eliminate timing chain tension issues while its off, pretty easy to check the timing marks and tension of the chain. Use a small mirror or the front camera on the phone to see the marks on the end of the camshafts. Again there are a few videos but this does a good job explaining.
     
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  9. jd1959 Top Contributor ★ ★ ★ ★ ☆

    Ireland Zack Kilkenny
    536
    314
    @Whisker Version This is pure uneducated guessing but I was just looking through the older threads I missed and you had VTC solenoid issues there a little while ago. Given the 1800rpm noise which is around the point the pins in the intake cam engage the second intake valve fully, is it possible that the rattle potentially caused by something in that system? There are two other screens that can cause problems with the VTC/VTEC oil flow #11 and #5 in this drawing.

    As I said well out of my depth here but just trying to think of other possibilities that could be explored or discussed by more experienced and knowledgeable folks.
     
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