Need Help!

[Meccathor]

I think that I may have a big problem with my 240, and could use some advice.

I was driving back to school today (Pittsburgh, PA to Lafayette, IN) and all was well during the drive. As soon as i got off the highway when i arrived in Lafayette, i heard a rattling sound. At first I just thought that it was something in my dash, but it sounded like it was coming from outside. So I rolled down my window and could tell that it was coming from my engine bay!

I pulled into my dorms parking garage and opened up the hood, with the car still running, and it was very loud. After listening for a bit, it sounded like it was coming from the head of the engine, and when i put my hand on the front of the head, i could feel something bouncing around in there....

In case I didn't explain clearly enough, this is where it's rattling...
http://home.comcast.net/~meccathor/engine.JPG

It's a '91 240sx 5-speed w/ 108k miles. and other than the rattling it starts, sounds, and drives perfectly normal.

My question is, what can I do about it? Are there any precautions I should take to take the head off the engine? Any tools that I will need other than a ratchet? Any info or help would be greatly appreciated! Thanks.

[Jeff240sx]

Take the valve cover off, and there will be a timing chain up front, along with a metal guide. It's dead-center of the chain, and bolts into the head with 2 bolts. Remove that.. takes 5 minutes, and check under the guide (side facing the timing chain). If its all scratched up (or broken off, I've seen that too), it was probably your issue. If it still rattles, the only other thing I can think of is you'll need a new timing chain.
-Jeff

[Meccathor]

Do I need to drain the oil or do anything else before taking off the valve cover, or just take off the 12 screws?

Also is it safe to drive around like this for a few days?

If the problem is the guide as you suggest, is it an easy fix? I only have some basic tools with me at school, or would your recomend that I bite the bullet and take it to a dealer?

Thanks for the help.

[mrmephistopheles]

all you need is 10 and 12mm sockets.
Go spend 10 minutes doing this and be done with it.
Be careful when reinstalling your valve cover - those bolts only need 7-9 ft-lbs.
IIn other words, only snug the bolts down. They snap easily if too much torque is applied. Sometimes the head will strip too.

[Meccathor]

When I take the valve cover off, can I reuse the gasket, or do I need to put a new one on?

And do I need to use any gasket sealer or anything when I put the cover back on?

Thanks.

[007jpang]

if the gasket seems messed up just put a new one on

[Meccathor]

Alright, I took it all apart and sure enough, the chain guard was sheared off from where it's normally bolted on and was just sitting on the chain. i took it out and put everything back together. There is still a fairly faint rattling but it is only noticible with the hood up and being outside the car.

[ThatGuy]

Welcome to owning a 240sx.

[Gjohnson7]

Good info to know. My 240 is making a rattling noise also. Do you know if you can just pick these parts up at Autozone (local parts store) or do I need to go to the dealer.

oh, gasket, chain guides and such.

[sykikchimp]

if you can get them at an auto parts store, they will usually be much less expensive than at the dealer. Most of it you can just get at autozone.