ClowesClause

25-April-19 Update: https://zilvia.net/f/showpost.php?p=6340449&postcount=8


Can someone tell me what this sound is. Just all of a sudden started happening.

Please excuse the Snapchat video:


https://www.youtube.com/watch?v=uju0H6Wcs24



From my local forum: (-" " designates quotes)

-"does it keep making the sound if you hold it at rpm"

dont know. Had flashes of rod knock so I ran it just long enough to take the video. But it doesn't do it at idle.

It does seem to be coming from the top half of the motor but I can't be sure.

-"Im gonna go with timing chain tensioner or guide"

was talking to a buddy and he said something along those lines too. Like the tensioner popped out and is creating slack on the timing chain.

The car is just stored right now, could it be a lifter just ran dry and isn't making up the clearance on the rocker arms?

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jr_ss

It's definitely not a lifter. That is something rotating at engine speed. It doesn't sound like rod knock because it should speed up with RPMS not become audible when you let out of the throttle. Could be timing chain guides, but that's more of a rattle not a knocking sound as yours appears to be.

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My SR20VET

Kingtal0n

If only you had a quiet exhaust, we could hear the engine

I cant tell you from the video, but you can check a few things,

1. maybe that fan is hitting something?
2. try disconnecting each coilpack one at a time and see if the noise goes away
3. replace the chain tensioner (easy and quick to do without removing anything else)

cotbu

If a power balance test doesn't help isolate the sound. Remove the valve cover and look around, take pics and post if you can't make heads or tails.
Sounds like the top guide is absorbing something, I would remove it temporarily and see if the sound goes away. I first thought flywheel but then i was like chain then like hold up, tossed guide and shim, now I'm like idk

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LoverTechnologies "Half Broken Things!"

derass

Sounds like the timing chain / guides.

ClowesClause

so bit of an update...

took off the valve cover to see whats what and nothing seems to be out of place or unusual.

did notice some wear on a cam lobe (exhaust side) but using the highly scientific finger nail resulted in barely anything (ie: barely noticed it)

long shot checked the turbo and there was the usual small shaft play for a stock turbo, so a little but nothing to write home about...side note, can the compressor housing rotate a bit and be normal?

buttoned her up, primed the engine with oil, started with no spark for a bit (oil pressure) and ran and noise seems to have gotten worse. became constant at a point so idk wtf it is.

thought it was like clutch fork or trans input bearing (trans is not the healthiest :P) but idk. have more pictures and a better video.

video: https://www.youtube.com/watch?v=e-o9...ature=youtu.be

pictures: https://drive.google.com/folderview?...sharing​

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zombiewolf513

I'd look at the timing chain guides and tensioner, and make sure your cams are bolted down properly.

ClowesClause

Sorry to resurrect this old thread but it has all the links and discussion on it.

tl;dr: strange knocking noise persists after suddenly starting, tests yield nothing

just to re-cap, noise started suddenly after sitting for about 1-2 years, would start up every month or so and ALWAYS prime oil and fuel before firing

Noise still persists, still cant figure it out, here's what I've done:

• Changed timing chain tensioner - have new guides but dont want to replace just yet (see what you have to disassemble just to change them )
• Removed upper chain guide
• compression test - ~150 across all
• checked cam bolts and rocker arm for play - tried to wiggle the arms when cam lobe not activating it and none wiggle in the slightest
• Power Balance Test? - running and up to temp, unplugged injectors, no change. changed plugs before hand for good measure

As janky as it may seem, with thinking along the lines of rod knock, did this test where you rotate the engine to 90 after TDC for each piston and CAREFULLY push down on the piston with a tool. Idea is that if there's too much clearance on the rod bearing that you will feel a noticeable drop.

Didn't feel this "drop" on any cylinder but its not exactly "scientific" so who knows, just thought I'd mention it

One last thought, and its a looong shot. The transmission if pretty crap TBH, and has already been replaced once. For reasons that would take too long to explain, when replacing it with a new(er) gear set the shim for the counter shaft front bearing was left out (its the one under the front cover inside the bellhousing), yes mistakes were made. Back when i did this i daily-ed the car, 3 years and 2 different shells later never made this noise although it leaked a fair bit (unrelated gasket)

Maybe, just maybe when i put it in storage the trans lost enough fluid to cause some sort of damage. I always used redline oil in the trans (prob too much of it cuz i filled it from the shifter hole rather than the plug, was a past life-little older, little wiser) and as i'm typing this realizing i could just put it in gear and step on the clutch to see if it is that does anything, but whatever.

its a bit hard to work on my car as its on a significant grass side hill, and cant be parked elsewhere for more than a day, so short of doing an engine rebuild (dont want to drop too much money into this engine if it can be helped, just want to drive the car and plan is to eventually put an RB in there so rather not spend the money twice),
does anyone have any advice for where to go with this?

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ClowesClause

ok im lost.

started it up last night and went to move it a bit and when the clutch is pushed in the knocking noise stops. even when rev'd, but only at a full press of the clutch pedal, was kinda there when about half way (ie: slipping to move) but not as much.

sooooo transmission/clutch assembly problem???
anyone experience something like this before?

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jr_ss

I’d check your throw out bearing.

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My SR20VET

OnTheChip

Could be broken springs in the clutch disk.

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NismotronicSA - Speed-Density Tuning for Nissans

doridoridori

have you recently installed a new clutch and/or adjusted your clutch pedal? also how old is your pilot and throwout bearing?

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If I had a dollar for every pet named "nismo" by a nissan owner Id be rich

ClowesClause

clutch was replaced ~6.5 years ago with everything new (fly, disk, Press Plate, throw out, pilot) but only about 10k KM ago.
Its a SPEC stage 3 btw. (6 puck, sprung)

I didn't replace the pivot ball or springs (maybe throw out spring, don't remember if the clutch came with one or not, if it did, I did) and haven't adjusted anything at the clutch pedal.
I did remove the junction block thing that's in the clutch line on the right frame rail so its just Master -> slave, but i don't think that would do anything would it and it was when i was still driving the car.

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