HI I have a DOHC KA24DE on my 93 240 .My timing chain is rattling and make so much noise so ,I went to AutoZone they said my timing chain got some problem, well I never had experince with Timing chain, and I did some resarch on it, I foudn some wonderful site about everything I need to change the timing chain. so I decided to change it myself. at the begnning it seem ok, but once I reach to the water pump and below all the belts, I got a headache, I realize it is not easy to do it, so I asked around,and they said , it does not need to change a timing chain, it is chain not belt, but I am not sure if it is true, now I am in half way to reach to the timing chain, I haven't take out the bottom cover yet,neither those 3 belts, I just want to know is there any way I can fix(STOP) the rattling noise problem???? is it possible if I can just adjust the new tenioner,??? or I really need to replace to a new chain and everything....

thank you

I've done two of these and there isn't any way to fix it. you can try taking off the two top guides and see if that fixes it, but it probabally won't. Here's the info on that; When Nissan designed it, they places a guide on top of the top double chain inbetween the cams. They also placed one on the drivers side opposite the tentioner. It was later realized that neither of these did anything but make noise and that the tentioner was enough to keep the chain in place. !!! This is only for the top chain !!! I would reccomend trying to do that first and see what happens, but trust me, you are prolonging the inevitable. It is usually the bottom chain/ tentioner that is the problem. The top one is short enough that it can't really do much, the bottom on the other hand is really long. If you want me to, I can replace it in a weekend. (for a small fee, hehehe)

I have the same rattling problem at low rpm. It goes away at high rpm.Mine is a 1993 with 110k miles.

I know it is the timing chain. Now, does it have to be replaced? I got mixing answers from the forum ...What the risk of living it the way it is?

Thanks

it probably isn't the timing chain because the chains on the dohc engines were remedied from failure of the chain itself, but it doesn't mean it could be the problem.

it most likely is the timing chain guide because those things can break off and when that happens, it could get into the worse possible places in your engine and destroy the engine.

the guides are no longer in service and can be removed because they do nothing but make more noise...i've yet to remove my guides...

HachiRoku, thanks for your reply.

What does it take to get to the guides and remove them?I mean, do you have to open up the whole thing anyway, or you can get there from the top without removing the front ...

...sorry, I need a little help here ... I'm not exactly a "pro" ...

thnx again ...

When my chain was making excessive noise, i thought i would investiagte. So i took off the valve cover and discovered that the top chain guide was just danglin on its orginal attachment. Its extremely easy to remove your upper chain guide. All you have to do is remove your valve cover and simply unscrew the guides bolts that hold it in place and pull it out, you can choose to put the screws back in. I don't think you have to, but I did anyway.

Hey guys, thanks again, this is great feedback!

I understand there are 3 chains: 2 upper and 1 lower. What about the lower chain? It has a tensioner on one side and guides on the other

It could be that one as well...

I guess I will have to open it up anyway to see what's wrong. But, can I reach, and eventually remove, the lower chain guides just removing the valve cover

Thanks again so much!:)

todi wrote:Hey guys, thanks again, this is great feedback!

I understand there are 3 chains: 2 upper and 1 lower. What about the lower chain? It has a tensioner on one side and guides on the other

It could be that one as well...

I guess I will have to open it up anyway to see what's wrong. But, can I reach, and eventually remove, the lower chain guides just removing the valve cover

Thanks again so much!:)

No, there are only two chains. There are two tensioners and three guides. The guides you want to remove are the 'top' and 'upper', the top is right underneath the valve cover, easy to get to, the 'upper' is behind the upper timing cover, beside the distributor, a little more work but still easier than a chain swap.