Is low rpm rattle the timing chain guide?

[jaja]

I have a '93 240SX Conv. that has a rattling problem. I have done a search here and it has the same symptoms as for the timing chain guide/tensioner. The only thing different is that I hear the rattling at IDLING only. Can anyone tell me if this is the timing chain guide (top)? if so here are my questions.

1. some forums say that I can take out the guide completely. question is should I replace it or take it out and leave it out.


2. I have never taken my head cover off... looks pretty simple, but scared. should i have it done by a "pro"

3. If I do do I need to replace the rubber gasket completely or reuse the current one with some liquid sealant near the cam edges?

Help is appreciated.

J

[sr240mike]

Its sounds like the tensioner is giving up. Might wanna replace that. Don't be afraid to pull of the valve cover. And yes ues some gasket sealer around the cam edges.

[2240sx's]

Please replace that soon. My rattle was only present at certain rpm's and all of a sudden the tensioner crapped out and it sounded as if the chain was riding the top of the gear teeth as I rode down the highway @ 75mph. Not a good feeling.....

[jaja]

so the best way to go is to replace - not to just take out and leave out huh.... if so I think there are 2 or 3 tensioners - do i have to change all 3 or does the top one that can be accessed by just removing the head cover crap out alot?

thx

[rps13sh]

there was a post with some nice pics. might not have been this forum. check around before you do anything else. best thing to do, just get a SR =)

[rps13sh]

here, maybe this thread will help you.
http://www.zilvia.net/f/showthread.php?t=68122&highlight=timing+chain+guide

[Turpentine]

If it is the timing chain guide, replace/remove it ASAP. I bought my car with the engine seized and the guy didn't know why. Turned out the chain guide had shattered, clogged the oil filter tube, and the chain ripped a hole right into the front seal into the waterway for the water pump, so the oil was full of water. Not a good thing.

[MELLO*SOS]

Yup this is a pretty common problem with 240s... My 92 has the exact problem you're talking about, a rattle at sub 1000 rpm levels. If you take off the valve cover you'll see a guide at the top that can be removed, it looks like a L shaped bracket with just 2 bolts holding it on. Nissan says this peice isn't required any more and that there's no harm in removing it and throwing it away. It'll take you all of 10 minutes to take off the valve cover and remove this guide.

On my 240 the rattle sounds like its coming from cam sprockets right under the valve cover, so I was certain that ditching this peice would solve my problem.... Needless to say, my guideless 240 still rattles like a can of flat black primer at anything under 1000 rpm. Your mechanic will tell you its >$800 in labor to replace the chain and tensioners :( plus another few hundred for parts. FYI you can buy a used KA24DE for about $350, so why waste all that money when you can a) do it yourself for about $200 in parts (look on ebay for "KA24DE Timing chain") or B) wait for it to go then swap in the engine of your choice (ca, sr, rb, hell even a used n/a KA). Once you read the FSM and see what's involved you'll probably opt for B, but lots of people on here will probably tell you "it's not that hard" and tell you to do it yourself. If I had a decent garage then I'd probably just do it myself, but I wouldn't want to undertake something like this in my carport :)

BTW my car has had this rattle for months now with no ill effects yet (knocks on wood).

Good luck! :hyper:

[jaja]

hey guys - thanks for the help, i'll try it tom - do i need to replace the rubber gasket? or can i reuse it.
I don't mind buying a new one - its just that I don't want to wait forever for the part to come in. (can i get a generic one? or should i get the legit nissan part?)

thx

[Pacman]

[QUOTE=mello88] If I had a decent garage then I'd probably just do it myself, but I wouldn't want to undertake something like this in my carport :)
[QUOTE]

I took on a used KA swap in my carport!! I know how it feels, everytime I need to work on my car, I wish I had the garage. Out in the elements; sometimes it really sucks.

[jaja]

hey pacman - you'd be surprised what i get done in my carport :)


timing chain guide update:
Well I called the local nissan and they want $46 for the gaskets so i figure i'll go with the legit ones.

i'm picking them up tomorrow.

[projectRDM]

People are confusing 'tensoiner' with 'guide'.

There are two tensioners, and three guides. The tensioners maintain tension on the timing chains through oil pressure, when they go out they require replacement, while you're in there it's best to do a full chain job.

The guides, however, can be discarded without worry. The top guide, below the valve cover, and the upper guide, behind the upper front cover, are generally the culprits of noise, both are a delete item from Nissan and should not be replaced. Taking the valve cover off is easy, then from there the front cover comes off with three 10mm bolts and six 12mm bolts, the distributor will also need to come out.
The bottom guide resides down by the oil pump, it remains.

There's more detail on the removal procedures here on this forum and others.

[nismo2491]

I'll sell you my timing chain kit cheap, sounds like its exactly what you need.
KEvin

[jaja]

Ok - update on the "guide" - SUCCESS!!!

but the downer is that the 10mm front bolts #1 and # 8 below are stripped. #1 is 90% OK but I can feel that it is stripped - and #8 is beyond help.
Dunno how to say it but the thread on the bolt is ok - bolt 10mm head is ok - but where it is supposed to bolt on to is stripped.... (just trying to be specific)


(I don't think it was me - I bought a torque wrench just for this... :( and had it at 10Nm)


<- front

1 2 3 4
5 6 7
8 9 10 11

So my question is this.... what are my options and is it dangerous to drive as is.... also i am assuming 1-4 and 8-11 are the same 10mm bolt (just hoping that the previous mechanic was a bonehead and used short bolts.)

- Can I use/try longer bolts?

- Do I have to take out that entire distributor section and get that piece of the head (dunno if that lingo is correct)


Pls help

J

[Pacman]

Why can't you re-tap the stripped bolt? There might be a leak where the bolts are. You could put silicone in the hole and on the threads of the bolt as a temp fix. That may help with the leak.

[jaja]

I know everyone on this board has done this before - but it was a first for me and took some pics of how it looked inside.

http://washington.jaja.com/s13/imgs/IMG_7834.jpg
This is a wide shot of what it looks inside.


http://washington.jaja.com/s13/imgs/IMG_7835.jpg
This part is supposively the part that caused the problem. Dunno what its called, but I removed it, kept the 12mm bolts that held it in place out too, and no more rattling sound and a happy wife.

[MELLO*SOS]

Cool, I'm jealous that it solved your rattling! I was sure it was going to solve mine, but nooooo

It's funny that your #1 bolt is stripped (okay by #1 you mean passenger side corner on the valve cover right?), because so is mine. Apparently from someone else. And it looks like they tried to fix it with that helicoil stuff (i forget the name).. It's easy to strip aluminium :(

[aznpoopy]

that sucks that you stripped those bolts... if you buy new ones, they are really fucking expensive. and you can't do something simple like use a spiral tap to get them out again b/c of their location relative to the valve cover.

so was the guide loose? or was it secured tightly? if the guide was secured tight, then you've only killed a symptom of the real problem; you need to figure out why your chain is going slack (which is why it was pinging against the timing guide). should've at least checked your top tensioner while u had the valve cover off. low oil will do it too.

[twitchy]

if im absolutely positive the sound in mine is coming from the top of the valve cover (ie where the guide pictured is),,,and i mean POSITIVE thats where the sound is coming from, and i remove that piece, will it stop??

The stealership says if i change the oil religiously the tensioners will be fine, and i do

[aznpoopy]

u should take it off. takes like 30 minutes tops. afterwards, u need to let the RTV dry, but otherwise it's a quick and painless job. if it still rattles afterwards, then you know for sure you have other issues.

[jaja]

i check alot of the tensioners, and everything looked fine.... the guide didn't have any looseness either. I know since its got 130K miles on it, its due for some serious engine work one of these days, but I didn't see any serious issues...

twich - it was really an easy job - the part that took the most time was removing the gasket sealer that the guy before put on. other than that it was 11 10mm bolts. Oh I would definately get a torque wrench so that the valve cover is put on level.