timing chain question
 

Hey guys, so I'm new to the 240sx world and have been researching them ever since I bought my 1990 sx. The only problem I see is of course the tensioners failing. My question is how do you know if they are bad? I read all about them breaking and falling into the oil pan & cutting into the timing cover but nothing on how to check them. I took off my valve cover gasket to see an amazingly clean set of valves and cam for an engine with 173k on it to see the timing chain. The left side of the chain was tight but the right side was loose. I looked down in there w/ a flashlight and the guide is still there although I could swivel it back and fourth. Is this normal? I drive this car about 45 miles a day and although its not a noisy engine I dont want it to break down on the expressway. All the other maintaince is up to date. Is it worth it to replace the timing chain/tensioners with this kind of mileage or better to look for a replacement engine since its so old. I figure I could get a low milaege engine for what it costs to have this repair done. This is a commuter car so I dont want to install a larger engine (althought it would be nice) just keep this car freeway worthy. Thanks for your help!

the timming chain is not really that hard to replace if you have the tools and the know how
here is a link to a service manual http://www.zeroyon.com/index/content/view/24/47/
dont know how much a shop would charge to do it or how cheap u could get a new motor for but if this one is strong still i would just do the chain


i need to mine bc it has been rattling for about 5000+ miles (needed time / $$)

look the chain fro cracks in the links, or look at the sproket of the cams and the lower one for sings of wear such as very pointy sproket, instead of a sproket that looks squared on the teeth. Beware that chains anbd sprokets are very sharp and a cut with oil is painful. Removing it is a brezze (the uper one.) just remove the valve cover, the uper front chain cover, unbolt the cams and the big bolt that hold the center (big) sproket into place and the guides, which you'll replace and thats it. the manual should tell ya all about it. I've removed 2 set of these in the past 2 days, so I know. One thing to keep in mind. when you remove the cams, remove all the holders except for the one's in the rear of the engine, loosen them in the right order (check guide) but keep those. Then after you are ready to remove the cams, then remove those. also , the front part of the cams will be tight and hard to remove. Hit it with a ruber mallet to pry them up. Hope that helps.