SR20 nasty rattle. Yet another vvt rattle thread?

[Matas]

My car has always had a second of vvt rattle upon starting, for the two years I've owned it.

A week ago the car completed a trip to Wales where it was driven damn hard. For that week in Wales, it had a few changes from the setup it had been running for almost 2 years before. Different t28 turbo, new turbo gaskets which resulted in an increase of boost and a hdev stage 1 ecu. It was beaten on like that and worked mint all week.

Got back and installed an electronic boost controller, just left to go set it up and the car starts rattling more when moving around at slow speeds. Within 20 miles the rattle sounds like death, we pull over and shut it off. Decide to unplug vvt and start it again, sounds mint again. Another 5 miles later we plug vvt back in and it's still fine. Had thoughts that the boost controller was somehow to blame but it's probably coincidental, but it has remained unplugged ever since.

The following day it drove another 250 miles to get me back home without any issues or performance decrease. However after running on the motorway for a while you can hear it rattle quite unpleasantly once you slow down.

Most people I talk to seem to think it's vvt rattle, however most cases of vvt rattle im seeing, the rattling occurs on idle and goes away upon acceleration. My car currently sounds pretty normal on idle, you can hear a tiny rattle maybe every 10 seconds or so, however if you give it some throttle it doesn't sound right at all. The rattle increases with revs.

I filmed a video from the engine bay and one from the cabin with some free revs and moving off back and forth. Its much quieter in the cabin and once the revs get higher its not actually audible due to the silly exhaust.

Just wanting some more opinions really, wanting to be certain it's vvt rattle before I continue using it. Ordered oil and a filter which I'll change just incase and check for metal fragments. Could film with an external mic in the engine bay to see how it sounds whilst being driven.

If not vvt rattle, then maybe chain tensioner or the chain itself? Or rip bottom end.

Any input would be greatly appreciated!

[Matas]

Interior video

[Joe1989]

I'm no expert but it sounds like the chain is rattling/griding off something.

[Matas]

I guess it could be worth looking into the chain tensioner and chain guide rattling. Looking back at old pictures with the valve cover off, it looks like I still have the chain guide in place which supposedly can be removed. Also looked up that the chain tensioner for my sr20de fwd p11 primera is supposedly the same, but it probably doesn't make sense to have both cars not functioning for the sake of swapping them round, probably a bit job too, can't imagine a replacement would be much.

[ANDY black s13]

I'm thinking its chain hitting something,it's not vvt rattle sound and I know that sound as went through 3 sprockets on an old SR I had
and recently had a high miler 200sx, on idle it was terrible 'clack clack' rattle and went away with revs
your's is the opposite and don't sound like the sprocket, check tensioner (the chain is loose/slack) or guides as mentioned before me

[Matas]

Yeah due to the fact it increases with revs as opposed to vvt rattle where it goes away with revs. It makes me thing chain rattle. If the chain has become loose then I guess it could be hitting that chain guide under the valve cover. Is it common practice to remove that chain guide with no consequences? May have to source another chain tensioner and remove that guide at the same time. Would a used known working unit be fine or am I best getting a new Nissan one. Seeing its £50 quid or so for a new one.

[Mike41288]

Any idea if you still use that top chain guide? I seem to remember there being a thing ages ago about them causing chain noise and everyone removing them. If you're popping the rocker cover off to check the chain guides anyways, it's something to look at.

Sent from my SM-G950F using Tapatalk

[Matas]

Any idea if you still use that top chain guide? I seem to remember there being a thing ages ago about them causing chain noise and everyone removing them. If you're popping the rocker cover off to check the chain guides anyways, it's something to look at.

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This is exactly what I'm on about removing in the posts above as it was still there when I last took pictures with the rocker cover off. I forgot to specify that I meant the upper one in the rocker cover. Strange that they're there if it's an unnecessary part.

[Matas]

Whoops. Double post.

[ANDY black s13]

straight cam SR is the one that had chain guide noise problems ,the picture is a straight cam
bent cam vvt dont have that guide between the cam sprockets
the tensioner serrated teeth (part of the rachet mechanism to prevent it going too slack) can wear to a smooth spot and the chain tension fluctuates
if it is a tensioner issue the chain is rattling lower down on the guides in the front cover/oil pump housing
don't try a used one if you can get a new one for 50 squids

[Matas]

straight cam SR is the one that had chain guide noise problems ,the picture is a straight cam
bent cam vvt dont have that guide between the cam sprockets
the tensioner serrated teeth (part of the rachet mechanism to prevent it going too slack) can wear to a smooth spot and the chain tension fluctuates
if it is a tensioner issue the chain is rattling lower down on the guides in the front cover/oil pump housing
don't try a used one if you can get a new one for 50 squids

I happen to have taken a picutre of my engine with the cover off and it seems like it does have a guide that looks like the one above, someone else said that they were removed for the S15s?
This is my engine, that's the same guide right?


Yeah I'm seeing a new tensioner for £55 from Conceptua, plus another £6.50 for Gasket and O-ring. Alternatively theres a used one for sale that's £15. I guess I need to look into how much of a shitty job it is, if it's turd I don't want to be doing it again I guess. I'm not even certain if it is chain rattle, hence I don't want to spend the money, plus I'm a cheap Northerner.

[ANDY black s13]

could have sworn the bent cam was different, I know the straight cam is the one that rattles and people remove it
I had to swap broken rockers/damaged cam shafts and fish cam shims out the sump,and swap vvt sproket countless times and don't recall it on mine

Anyhoo looking at the picture,it may be a trick of the light? but No2 inlet cam lobe looks to have a wear ridge on it's outer edges,
if it has worn that lobe likely spray bar is blocked and the cam and rocker have worn,but may just be the picture tricking me?
that's the suspect for the noise if it's worn the cam lobe, and the chain tensioner or chain hitting something was just an untested/checked suspect
don't buy any bits just yet till we narrow down what it is

[Matas]

I hope it is just the picture and the cam isn't worn due the the spray bars being blocked. I only have one other image of the exhaust cam up close, I think I'm gonna have to whack the rocker cover off.

https://flic.kr/p/MsHzFY

These pictures were taken in March so if there was damage already at that point, it may be poop now.

[Matas]

Took off the top chain guide and the rattle is gone. I did buy a new chain tensioner and will change that too since all around the current tensioner there is loads of oil sludge. Bought it now anyway so may aswell.
. Unfortunately managed put the valve cover back on with the gasket not sealing properly so oil is departing my engine rather quickly. Got to fix that now, oh well.

[ANDY black s13]

good that was the fix the free ones are best,I guess the chain is a bit slack so new tensioner would sort that,
the leak may be the gasket got caught down the back on the bulkhead seam and the crap behind the head
hopefully its just needs relocating,glue it to the cover if not already

when you swap the tensioner extend the plunger and check if the teeth are worn or not as curious if that whats happened
or the hydro part is worn and leaking off pressure and it can't take the slack out,
there is a manual adjustable version if you want to get fancy with it you don't really need it the one you have will work fine
looks cool though
https://frsport.com/mazworx-10181-sr...BoCzYUQAvD_BwE

could probably convert the stock hydro tensioner to a manual easy enough , threaded bar, nyloc nuts and some common sense
I'm doing 2 for a motorbike project soon as known to wear the teeth and they collapse/retract on shut down from high speed on my engine
few engines survive the cam chain or belt going super slack and it jumping teeth