Basically, at idle and momentarily at low accelerating RPMs the motor would make a sound like the chain was hitting the guide so that’s why I pulled the valve cover. It wasn’t a continuous noise, just on idle and these various instances.
Upon inspection, the top guide was perfectly mounted on there. It was not loose at all. I took the top guide off and it had some minor abrasions in the top from the chain.
The timing chain has a little bit of slack in it (granted the tensioner is operated on oil pressure). I took a screwdriver and I poked around on the chain down on the bottom tensioner and it was pretty tight. From the pics, do you think the chain should look like that?
I did not take off the front cover to physically inspect the tensioner because I am a noob and I don’t have the tools to take belts off. Hopefully, this will get rid of the momentary rattle.
Is there any other stuff I can inspect with just the top valve cover off? Maybe it would be worthwhile to put some rocker arm stoppers in there now.
As a side note,
My valve gasket cracked in half, so I need to get a new one. Who would have this and how much? What is the procedure in applying the sealer as well (I bought some stuff by Permatex “The Right Stuff”)? I don’t have a torque wrench but I am going to hand tighten the bolts in the suggested pattern in the FSM.
There should be “some” slack. That looks very minor to me. It would depend on where you are on the rotation. If you turn the crank, that chain will tighten and loosen with the rotations.
Rocker arm stoppers won’t change anything with regards to the timing chain. That is just to stop, well, the rocker arms from jumping off.
Oh, and to take off the front cover, you have to remove the oil pans, yes both, as the cover has the oil pick-up bolted to it.
You could take off the tensioner (two small nuts), and then have a peak under the chain and see how bad the markings are on the two chain guides under there.
Ok, I see what you are saying with the tension relating to the cams.
From what I can tell there doesn’t seem to be any slack anywhere else. The tensioners job is to get rid off the slack between the intake gear and the bottom gear? Right? So even if that would be working, it wouldn’t really matter on that slack between the two upper gears.
I think the wear on the top guide was very minor. There were no actual bite marks into the metal but you could tell there was some abrasion. You think it’s a good idea to get rid of this guide?
Do Nissan dealers carry the gasket kit? I am going to try to get that tommorow and try some Permatex Red as I hear “The Right Stuff” is a bitch to get open again.
As far at the front cover goes I won’t even attempt that because 1) I am too much of a noob and 2) I don’t have a lift or all the tools.
Just one question, what motor are you working on? I know for rebuild Ka24 they (experienced altima/240sx re builders) remove all but one guide and that one is from the crank to the cam section on the slack side.But again, I’m not sure what motor you have there… So cant help you entirely.
Thats an SR20. I know on the KA the chain is on there tight, and doesnt have that slack unless you just assembled cams and stuff but have not started the engine yet.
I’ll try to rotate the intake cam counterclockwise to see if the slack goes away.
If the car is actually on, and there is oil pressure the tensioner should be putting more tension on the gears right? Maybe it’s just that when the car is off the tensioner doesn’t have enough tension to overcome the tension in the valve springs in that particular position.
I think in the final scenario I’d replace the chain but I don’t think it would stretch that significantly.
I’m wondering if I should tear down my 180’s SR20 and look at the timing chain… I hear a quick rattle at startup (usually three rattles) and my car usually rattles around 3000’s revs or so. One shop told me I had an engine knock, but it’s so sporadic and random. The rattling only seems to happy as soon as I lightly touch the throttle… Does this sound like a loose timing chain to any of you guys?
i bought a whole timing chain kit before i swapped my engine (so much easier with it out because like someone said^ the ‘upper/lower oilpans’.)
all front seals/o-rings replaced, guides and chain. infinity g20/sentra se-r kit works so ya…
also i remember the guides off the kit i purchased looked alot more sturdy/well built compared to what i pulled out of the engine…
rattling might be one of hte guides going as i remember my stanza’s guides going and being very noisy, turns out one of the guides pretty much disintegrated and all the plastic fell to the bottom of the oilpan :oops:
if you replace the chain, follow the FSM for S14, same thing i believe, worked for me…
I wonder, anybody think those same symptoms could also be a loose turbo charger exhaust manifold gasket or bolts? I hear lots of clicking, rattling and such from my top end when I drive, and I could be just imagining it, but when I’m driving it seems to be coming from the left side of the car… Under the hood when I blip the throttle it’s like loud rattling in my upper valve train… So hence the dilemma I have. I wonder where I should start looking?
I replaced my tensioner with the beefed up one and took off the top guide. Solved the problem of the rattle at idle.
I still have a funny sound midway through the RPMs and the top end but I think that’s the heat shield. There are three bolts holding it on, the third one has the head snapped off so it’s a little loose in that area.
My problem only seems to happen when I rev. At pure idle my car runs really quietly. It gets worse at 3k-3.5k revs, and then dissapears i guess cause my engine is too loud to hear it.
It’s also intermittent. Weirdly, only when my car is cold but sometimes after I’ve been driving for an hour or more. Or sometimes not bad at all…
So if my car runs quietly at idle, does that rule out:
a) rod knock/bottom end?
b) a loose timing chain?
Yeah, mine happened only when the car warmed up, not when it was cold. It’s hard to determine if it would be rod knock without hearing it. I doubt it’s related to the bottom end though. Does the car still drive well?
I ended up opening up my valve cover to take off the top guide anyway because it’s not needed. The rattle was still there at idle only after it warmed up. Have you checked the heat shield itself?
I’d do this if it’s indeed your timing chain:
heat shield
open valve cover (check timing chain)
tensioner
do the timing chain
But it can quite possibly be your HLAs as well. You could try bleeding them.
Yeah, my car still seems to pull strong. I mean, I’ve never driven another SR20 powered S13, but this car is wicked awesome fun to drive. Lately in the last two days the problem got really bad, but it’s so dicey. It’s almost like the more I start and drive the car every day, the better it gets. Wierd! :roll:
I doubt it’s rod knock too because I’ve put 12k kms on this car since I’ve gotten it from japan, and this annoying problem has always been there. It comes and goes.
I think the order of things you’re suggesting is great AdamP! I’ll do it in that order for sure. I’m just going to take the heat shield off totally and check the bolts… It’s safe to drive without the heat shield right?
I think it would be ok but I’d ask some other people on here.
I’m a noob still. I’ve only put about 3k on my Sil80 since I’ve had it. Basically, I figured it would be a pretty easy import to fix and modify. The other car I had on my list was the Fairlady but the VG30DETT is astronomical to work on.
Yeah, so far maintenance has been a dream. I’m a total noob too, and before I owned a beater Chevy Tempest (Corsica). I’ve never been able to change plugs so fast in my life!
The biggest thing I’m learning is how all the extra ‘better’ bits fit together! Like the fact I’ve never had a DOHC let alone a turbo to play with
My next biggest hurdle is figuring out why my gearbox grinds in 2nd gear! That should be a boatload of more maintenance fun on my daily drive. :axe:
