# timing chain loose, is it ok??



## edgarnissan (Nov 24, 2014)

good day friends to begin with i am new at car mechanics but i keep studing and practicing to improve my skills....

i was wondring if you guys could help me with one issue, i recently had with my 2000 nissan altima, the engine started a rattling noise in the chain side , so i knew there was something wrong there, i did all the procedure people had explained in past post in the forum... after i uncovered the chains i noticed the tensioners and guide were ok, the only "issue" i found was that the chain was loose at the bottom, it wasnt really tight.
can this be the cause of the rattling noise???? i tried to upload a pic of the "problem", and if it´s the problem how can it be fixed? is it a bad timing ? since its a metal chain it cant expand due use, right? the thing is it seemed really loose at the bottom, i could manipulate it with my fingers ... 
i really appreciate your help and assistance 
thanks!!


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## rogoman (Dec 16, 2004)

When the engine is not running, there will be some slack in the chains. There are two timing chains. Which one appears to be loose? The two main possible causes for a chain rattle are a worn out chain guide or a bad tensioner. If it's the upper chain assembly that's causing the noise, there's a Nissan TSB (technical service bulletin) that talks about eliminating the upper chain guides. Here's a web site that goes into more detail:

THE GARAGE GUIDES - Fixing the Timing Chain Rattle


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## edgarnissan (Nov 24, 2014)

thank you, the chain that is loose is the lower chain= the longer chain.... 
i just saw the web site you posted but its not the same as my engine, mine has the distributor at the other side of the engine not next to the timing chain, does it matter?? or is the same procedure?

is it possible to upload a picture on my replies so you could see my "problem"

thanks


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## rogoman (Dec 16, 2004)

Your engine is a KA24DE and the engine on the web site is also a KA24DE with minor differences like the location of the distributor. The timing chain service procedure should be similar.

A picture can be displayed on your posts but first you'll have to store the picture on a web site like photobucket.com and then link to it in your post.


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## edgarnissan (Nov 24, 2014)

thanks a lot here is "hopefully" the picture of how the lower chain looks like, i really appreciate the forums opinion if the chain loose situation is normal or needs attention.

IMG_6958_zps19864670.jpg Photo by edgar11111 | Photobucket

IMG_6957_zps07c35601.jpg Photo by edgar11111 | Photobucket

IMG_6960_zpsf3fb4b20.jpg Photo by edgar11111 | Photobucket

peace


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## rogoman (Dec 16, 2004)

The pictures do show a lot of looseness. The tensioner springs may be broken or there may be a lot of gunk in the tensioner oil passage.


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## smj999smj (Jan 1, 2006)

I think the upper chain guides were eliminated by the 2000 model year, so you may not have them. Since the tensioners are oil-fed tensioners (despite the spring inside them), it's hard to judge improper tension as there is no oil pressure to push the tensioner plunger against the guide. A lot of issues with chain rattles on these engines are a result of debris restricting the oil pressure to those tensioners, causing the chain to slack and rattle. Since the front timing cover is already removed, I would get a complete timing set and replace with all new chains, gears, guides and tensioners. I would also used carb or brake cleaner with compressed air to blow clear the oil channels to the tensioners before installing them. You can get some pretty good prices on aftermarket timing sets if you do some searching on Ebay or Rockauto.com; it'll get costly if you go for only genuine Nissan parts. Most of the name brand aftermarket sets, like Cloyes or DNJ, are of descent quality. It might be worth checking the oil pump while you have it off (it's part of the front timing cover).


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## edgarnissan (Nov 24, 2014)

thanks a lot, i guess i will go for the new timing kit, i can understand what you describe related to the oil-fed tensioners, but what is really strange is that the looseness is on the other side, the side where the guide is. 

is there a chance that the chain could expand due the use??

thank you


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## rogoman (Dec 16, 2004)

Any looseness in the chain will usually show up on the slack side of the chain because the tensioner is exerting some tension on the opposite side.

The way chains are built, they'll never expand that amount that you're showing. However the chain roller links could be excessively worn or cracked. 

Follow SMJ's advice and buy a complete chain assembly. Check for excessive wear/damage on the sprockets.


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