Trying to track down a rattle. I have searched, but have a couple questions.

[neverrain]

Hi,

I've been searching though this forum for the last couple hours reading through all the threads on rattling on the KA24DE. I've come across a couple possibilities, but wanted to ask a couple specific questions to my issue.

I have read that the possibilities to the 'rattle' could be the following:

1. Timing chain guides. I have removed the top, but not the lower. I know I saw a walkthrough on this somewhere but I can't find the damn thing now. I might have missed it when sifting through search results. If anyone has the link offhand, +rep for joo. I'm not 100% sure this is my issue though. I will explain below.

2. Loose valve cover. The is one bolt, that was stripped or the threads were gone on the cover. I'll have to run out to my car on my break and verify which it is. I had to use what I could find, and while i believe the cover is correctly seated and sealed (yes i replaced the gasket), I still don't believe this is my issue.

3. Motor mounts have gone to crud. This could be a possibility, but I'm not sure based on the info below.

Now let me explain my rattle.

The rattle itself literally sounds like it is right under the valve cover, although I haven't tested this with 2 people. It sounds like metal bouncing around a hollow area, like the timing belt hitting the valve cover for a few seconds, but i'm not 100% sure on this, and I doubt thats what it is. Just trying to give the best description of the sound.

-This only occurs after my car has been sitting for a while, like overnight or the whole day while I'm at work. It will happen everytime in this circumstance.
-This only occurs right when I start the car, and for a few seconds after.
-If I drive the car for a bit after it happens, then restart it after parking for a few hours, it does not occur.
-The rattle does not occur at all once the car has been started and the initial rattle has disappeared, only after it sits for an extended time.
-This has been occuring as long as I remember with this motor.

I swear it feels like the oil is draining from the upper areas of the engine and they are recoating when this occurs. The reason I don't think its the timing chain guides or the valve cover is because this only occurs at startup, not at any other time. I have used nothing but Mobil1 10-30 since I got this motor (had the car since 99[yep, back when it wasn't trendy to own an s13], 3rd motor, yes, i was young and dumb and drove the shit out of the first two, but have taken the best care possible with the newest one). There is roughly 70k-90k on the motor and it appears to run great, acceleration is clean, except for a slight delay once in a while in third gear right after shifting when the car hasn't fully warmed up. I have had 2 mechanics look into this issue and neither have been able to give me anything (probably because the frequency that it occurs). I am the third owner and the car has a clean title, according to Carfax.

If there is any information you need, just ask. Please be kind though, I'm still learning how to work on my motor, and am somewhat nub to the slang. I can preform most maintenance, but have never rebuilt a motor. I am loving this site and read it as much as possible to soak up info. And yes, I bought a premie membership right away because after all the info I've taken off this site, I felt like I should give something back.

I feel like I'm at the point where I need to find an s13 expert mechanic to get this resolved. I trust my mechanics, but they are shops that work on all kinds of cars.

Any help or guidance on this is greatly appreciated. Also, sorry for the long post, I wanted to explain this as best I could.

[WangonwWarrior]

put new timing chains/tensioners in and it will be all nice and quiet :) If the problem persist...valves:bash:

[neverrain]

Would the timing chain only cause this at startup? Seems to me that a bad timing chain would make this rattle all the time. My main issue with understanding this problem is that the rattle is only for a few seconds during startup.

Not arguing, just trying to understand as much as possible. I appreciate the feedback.

[neverrain]

Heh, you know something I just thought of too.

A little while back I had my timing adjusted back to 750rpm at idle because it was running higher (~1200ish) and it has worked its way back up to 1k. Is this relevant to your suggestion?

[WangonwWarrior]

I understand your questioning but its cold at startup, after it heats up and the oil thins it begins to quiet down. The only other thing that causes rattles besides shit falling off are like vaccum leaks, valves, etc...

[EDacIouSX]

timing chain is suppose tooutlive the engine. if the timing chain is worn out them somethign is fucking wrong!!!.


The way the tensioner work is based on oil pressure. hmm now that I think of it, it could be that the tensioner is going bad? Because whenthe pressure builds up (increase in RPM) the tensioner wll tighten the timing chain and loosen according the the level of pressure.

Now, i'm not positive but maybe because the car is cold the tensioner is not working that well and thus causing the chain to have slack. I've never heard of that problem this is just me theorizing.


Before I took off my guides (there's 3 of them), i had the rattle mostly at idle. didn't make a difference if it was warm or cold.

if i didn't articulate myself well enough, just ask me for some calrification.


so, as the person before me said, it could be the tensioner and I think that's a possibility. Though, fyi, the timing guides do not come in the rebuild kits and theres was a factory recall on the timing chains to have them removed for free back in the day. So,you don't need the guides because the tensioner is suppose to do all the work. if the tensioner goes out the chain can skip gears and your engien will take a fat shit.

[WangonwWarrior]

Heh, you know something I just thought of too.

A little while back I had my timing adjusted back to 750rpm at idle because it was running higher (~1200ish) and it has worked its way back up to 1k. Is this relevant to your suggestion?


Could be but at startup the tps will cause it to idle around their anyways and your rattle occurs at start up

[EDacIouSX]

Could be but at startup the tps will cause it to idle around their anyways and your rattle occurs at start up

at startup all engines have a warm up cycle.


ka's iirc are suppose to go 1100, 900, then either 800 or 700? depending if its Auto KA or Manual KA. Auto KA has higher idle RPM then Manual.

[neverrain]

Could be but at startup the tps will cause it to idle around their anyways and your rattle occurs at start up

EDIT - Checked mine a bit ago. Startup goes to 1300 (stupid rattle occurred again), then dropped to 1100, then down to 1k when the engine got hot.

ka's iirc are suppose to go 1100, 900, then either 800 or 700? depending if its Auto KA or Manual KA. Auto KA has higher idle RPM then Manual.Manual KA, i believe the year is 94/95ish. Learned that the hard way after searching the entire LA area for the s14 KA valve cover gasket after I realized the s13 one was slightly different.

[neverrain]

OK.

After reading a few other threads here about the timing chain tensioners, it sounds like this *could* be my issue.

I have another question regarding this. Forgive my nubness, but I'm learning. There are two of these things right? One sits under the upper timing chain guide (which is gone), and the other is where? Can the upper be changed without serious engine work? My plan is to test it first. I read that you can test its freeplay, if it moves that's good, if not its frozen. Is this correct?

Also, when I replace the valve cover, was there some sort of goo that i needed to put on the gasket? I have a feint memory of this, but I had an experienced friend with me telling me what to do.

Again, sorry for asking a million questions. Your help is very much appreciated.

[aznpoopy]

an FSM (factory service manual) would clear up those questions very quickly. try finding one for download online somewhere. should be more than a few copies floating around.

to replace the tensioner and remove the second guide you will have to remove the valve cover, the distributor and the front upper timing cover.

archive thread with a DIY:
http://zilvia.net/f/showthread.php?t=24976&highlight=timing+chain

make sure the follow the step marking the distributor very carefully or else you will have to retime the motor.

this is the front cover:
http://www.autozone.com/images/cds/jpg/small/0900823d8017f246.jpg

this is an exploded view of the components:
http://i10.photobucket.com/albums/a104/kirinpoopy/chain.jpg

i've circled the upper chain guide, the "lower" chain guide, and the tensioner in red.

RTV silicone is supposed to be applied to the half circles of the valve cover gasket.

if you're still confused there are plenty of write ups on the net that are more detailed. just do a search on google for "ka24de timing chain guide diy", or something to that effect.

[driftphenom]

http://zilvia.net/f/showthread.php?t=195699

been there done that