A handy alternative to a stethoscope, is to use a short length of hose instead. A 600mm or so length of garden hose is perfect.
YouTube Sound Clip Ok......here's a clip.... Cant seem to make the embedding of the clip work, so here's link: http://youtu.be/ojzGbz8oI0E [yt]http://youtu.be/ojzGbz8oI0E[/yt]
Damn Marcus, sorry to hear that it's still got a problem... That sounds even more worse now than before or is it just the video??
Yeah was very disappointed to hear the noise still there. I think the video was just better....noise is about the same.
that little bit of beat-up metal has been holding balancers in place way before you stopped shittn yellow, in-fact way before ya dad and even ya grand-dad even started with the yellow poop :rofl: yep its the way of the harmonic balancer........ and that little key WILL more than likely damage the actual crank key-way and / or the balancer long before it suffers. belive it of not it takes around 1.5 tons of pressure to shear that little piece of beat-up metal Teky nailed it, re-use the harmonic after you clean it up, it will see you out as for your rattle.......... I guess your next step is a plenum pull and rip a rocker cover off, sounds a bit like a damaged valve but more in the cam to valve area. A worn cam lobe, bloody rare in a ZX but more common in other engines sounds very similar, so I'd be checking the valve clearances as it sounds about as slopy as a two bit whore on a sunday morning have you got an intermittent bit of a choof out of the exhaust ? The rattle is distinctive, I recon if you hooked up a timing light the light pulse would be in harmony with the clack you have, that eliminates things like idler bearings etc Kingy
I have had a bit of smoke but while I was changing the cam gears I had a look at the PCV values and they were both stuffed (hanging open), so I replaced them. Yet to find out if that fixed that issue. Yes, time for a plenum pull and get those rocker covers off for a look. It does sound like that's where its coming from. Cant image there would be any valve damage. Engine has done about 2000km. Hardest work it's ever done is a dyno run at UAS. Anyway we'll see. I'm slowly becoming a mechanic.......
If the exhaust note at idle is even without any obvious popping or hard throbbing, then you can rule out something to do with rooted cam lobes. Even one ticking lifter can be clearly heard clearly in the exhaust note due to the changed valve lift. Reason I asked about it being an auto is i have heard an engine that was diagnosed by several mechanics and even its owner and myself as having rooted bearings. The noise turned out to be a cracked flex plate!!!! To this day I still have trouble getting my head around that one.... Im leaning a little towards that front pulley and/or its installation given the damage to the woodruff key shown previously. Is there any possibility that the big washer is actually bottoming on the crank before it sandwiches the pulley up against everything allowing the pully to "float' there rather than being secured? It may explain the damage to the key previously. It also makes me wonder if the cam belt pulley might be in the same condition and slogged out. E
Might not hurt to do an oil change and chop the old filter open? See if if looks like Christmas inside...
It's definitely up at the top of the motor - went to Marcus's and saw it in person, but yes does sound like a knock knock knock.... Marcus - do you have a magnetic sump plug? Or have you done and oil change recently? if not maybe worthwhile doing it and just checking the oil for any metal.
Where did you get the motor from? Did it come with warranty? Or is the problem not covered under one?
tassuperkart - it's idling nicely and doesn't knock if I bring the revs up slowly. The harder I hit the gas the louder it knocks. I replaced the harmonic balancer and Woodruff key and it all tightened up nicely when I reinstalled. Also I'm pretty sure the noise is coming from the top of the engine.....just doesn't sound like it's coming from deep down. Wizard- "death rattle".......shut up ......please Rob and Matt - I just did an oil change (day before the dyno day). Changed filter and oil and didn't see anything unusual then. I also dropped some oil out last week (it was slightly overfilled) and didn't see anything on the magnetic plug either. I think the next logical step is to have a look under those rocker covers. Not sure whether to hope to see something obvious, or to hope not to!
I think I mentioned this in another thread on here somewhere. I once had a strange rattle in an older Skyline that I thought was a pulley. Turned out to be a broken head bolt rattling around. Can't remember exactly what it sounded like tbh but could explain your problem. ie not seeing any other real affects other than knocking/rattling as revs increase. Pull the rocker covers and have a good look.
The motor was built by a highly regarded ex-forum member who shipped it to MRC to fit. The first one failed at first start so I had to then send the car up to Brisbane so he could rebuild it again. It's now done about 2000km since then, but workshop no longer exists so......no warrantee.
The highly regarded ex-members handy work failed the first time you started it after a complete rebuild, is that right? And now (I assume after another rebuild by the same member?) it has that horrible racket going on after 2000ks. It would seem you just can't trust anyone to do the right think now days.
