# 96 Timing Chain



## altimanum1 (Jun 19, 2009)

I got a 96 altima and it has the common problem of all altimas yrs 93-97 it has the tick/knock noise produced by the timing chain.

A friend of mines told me its because of the timing chain tensioner, he told me if i replaced the Tensioner the problem will go away.

My question is ... if i replaced the tensioner will the tick/knock noise go away?

By the way the car runs perfectly its only the noise, since im planning on selling it i want to fix that noise.


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## MD83Z (Nov 10, 2008)

Remove the valve cover and find the timing chain guide at the top. This can be removed 2 bolts and left off, for a little less chain rattle.


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## rogoman (Dec 16, 2004)

There are two chain tensioners; one for the top chain and one for the bottom chain. Typical chain rattle is most of the time caused by worn or disintegrated chain guides; there two which are located on the driver's side; one for the top chain and one for the bottom chain.

While you have the top chain cover off, you can look down along the chains to see the condition of the guides.


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## smj999smj (Jan 1, 2006)

A lot of people blame the cause of the infamous GA and KA engine timing chain rattles on the guides and the guides certainly due play a part, but they are not the initial reason for the problem. The problem begins with debris and sludge in the tiny oil channels to the chain tensioner(s). This causes a restriction in the oil pressure to the tensioner(s), which causes inadequete tensioner pressure on the "slinger" chain guide, which causes the slack in the timing chain which causes the chain rattle against the guides of the lower chain, and damage to the original plastic "fixed" lower chain guide until it breaks and possibly cause the chain to jump time. It also causes slack in the upper chain, which subsequently slap against the two upper chain guides.

The KA24DE has two areas where debris and sludge form and cause issues. The oil channel to the lower chain tensioner. When replacing timing componants, it's a good idea to remove the lower tensioner and oil filter and use carb cleaner and compressed air to clear out the channel. Blow through the channel until you see it blow out though the oil filter adapter.

The second area is behind the main gear, which is the gear that connects the lower chain to the upper chain. Sludge builds up behind this gear and can restrict or clog the oil channel to the upper chain tensioner, causing it to slap against the guides. Nissans "fix" is to remove the two timing chain guides for the upper chain. When replacing timing componants, it's a good idea to remove the main gear and clean out the sludge behind it. Then, remove the upper tensioner and use carb cleaner and compressed air to clear out the oil channel. 

While I like the metal backed design of the fixed guide better than the original plastic guide, it probably would have been fine if not for the issues of oil restriction to the tensioners. It was never an issue in the older Nissan/Datsun engines because they used two, metal backed, fixed guides with the tensioner only applying pressure at the bottom of the chain via a tensioner "foot." Even if there was some restriction in oil pressure, the fixed guides would still keep the majority of slack out of the timing chain. They also used a double row chain, as opposed to the single row chain of the GA and KA engines. 

Since you are selling the vehicle, removing the valve cover and the top guide for the upper chain may help somewhat. An oil flush may or may not help. The only true fix is to take apart the front of the engine and clean out the oil channels and replace any worn componants and install the updated guide, if applies.


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