Timing Chain

[II NizMo II]

I have a 91 240sx, they told me its canadian because i have the digital speedometer but im not sure if thats true..anyways my car has 142,000 miles on it and im worried that the timing cahin any moment will just break or jump a tooth because it sounds loose, can anyone tell me the chances of it jumping or breaking because if it does...im stuck like chuck..thanks:D

[nnkfws333]

How do you know it sounds loose? Do you hear it rattling at all? I have 190,000 miles on my motor and no timing belt change at all. All Ive ever done was tooken out the guides. I wouldn't worry because you can usually tell when its time for a change.

[TrueSlide]

The chances of it breaking, jumping are very likely. It would be a good idea to get it replaced when you can. Trust me Chain or rebuild motor, its upto you.

[II NizMo II]

it rattles right underneath the valve coveris it hard to change the guides only?

[TrueSlide]

Not hard, time consuming. Dont just replace the guides though, do the whole set: guides, chain, tensioner, defiently include the tensioner. But it would be a good idea to get a new chain, cause those can break, and I have a broken chain to prove such.

[Touchdown038]

If you have access to the guides, ie the front cover pulled and everything leading up to that, then you might as well change the chain too. It's right there.

[240nismo]

well if its under your valve cover, couldn't it be your valves?! or maybe your rockerarm is out of wack and tapping ... check the inside of the valve cover for nicks of any kind just to be sure

[Open4Cycle]

Hey 240nismo this guy has a 91 240SX which has no rocker arms.

[desiving1]

I suggest checking the location of the noise with a mechanics stethoscope. If it's mainly in the valve cover, rather than lower down the front cover, you may be able to take care of it by freeing up the tensioner (as suggested in the faq) and removing the top guide which is no longer needed.

any comments?