Nissan truck - timing chain rattle?

I have a 95 Nissan truck with about 120,000 miles on it. I sometimes hear a rattling noise from the front of the engine. It does not go away when the engine warms up, and I don't hear it when under load or at rpm greater then about 1500 or so. My first choice is timing chain rattle. 120,000 miles on a timing chain is a lot - but is that a lot for this engine? How long can this engine go before it looses the chain - do they drop them easily, or last forever?

Reply to
Zootal
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I have a 95 with 220,000 miles and the only rattling I have is the hood.

Striker

Reply to
Striker

Does it burn oil? Ever replaced the timing chain? At 120,000 miles, this engine does not burn a drop of oil.

Reply to
Zootal

The only things I replaced out of the ordinary items was distributor cap, rotor and fuel pump. It does not burn oil, neither did I have any problem with the timing chain.

Striker

Reply to
Striker

I took a closer look at it this weekend. When cold, no noise at all. When it runs for 5-10 minutes and warms up a bit, there is an irregular knocking noise coming from the front of the engine. It's not very loud, but it's noticeable. Not as heavy as a rod knocking or even a wrist pin knock, but not a light tap/rattle that you might get from a waterpump/alternator bearing, nor is it as fast as a bearing would be. At idle you hear it a few times a second. I took a stick and poked around a bit - you know, put your ear on one end, and place the other end on the suspect noisy area. It's nost definitely not water pump, alternator, or any accessories. Not the top of the engine. It's hard to get the stick on the front cover, but the few areas I did I could hear the knocking pretty clearly. I'm pretty sure it's coming from the front cover area.

Reply to
Zootal

I don't know if this is your issue, but back around '93-'96 or so there was a known issue with Nissan V6 motors if that's what you have. It's been a long time and I don't recall the specific but I believe it was something to do with piston slap. Most of us listened to our motors and if we didn't have it, we let it rider. Nissan had a TSB on it for warranty repair when needed. It affected a very large number of motors at the time.

Reply to
me

I've heard what I suspect is piston slap from the engine when cold since I bought the truck 12 years ago, and it has very slowly got worse. It still runs, so I ignore it. This noise doesn't start until the engine warms up. Actually, it only does it at a slow idle, which is why you don't hear it when the engine is cold - it idles faster. It's definitely not piston slap. Doesn't sound like it, and is too intermittent. Also this is a 4 cylinder engine. And is much more noticeably coming from the front cover of the engine.

Reply to
Zootal

on 5/1/2009 12:40 PM (ET) Zootal wrote the following:

My 97 Nissan 4 cylinder PU has a noise from the front of the engine. It is mostly heard when first starting the truck and the rpms are high before the engine smooths out to idle rpms. It sounds like a rattle that gets loud and then dies down within a couple of seconds with the rpms. It sounds similar to a loose exhaust pipe that is vibrating against the frame until the engine smooths out and the pipe stops vibrating. After that, the noise is much lower in volume and is just like a irregular tinkling sound that comes and goes. I've checked everything externally on the engine and exhaust system, but it not coming from any of those places. I bought the truck new and have had the noise for years and tens of thousands of miles. I only have 66,000 miles on the truck now. I suspect that it is the timing chain tensioner, but don't want to pay up to a thousand bucks to have it checked out and replaced, if it is not the timing chain assembly. I'll wait until it breaks down and then have it towed to a garage. I don't take the truck on long trips and probably don't travel more than

50 miles from my home.
Reply to
willshak

Piston slap usually gets quieter as the engine warms up, so I doubt it's that. Chain I reckon, a new tensioner may fix it good enough to quieten it down. I know that later Nissan tensioners on some other 4-pots have more teeth on the plunger for a finer adjustment and less noise.

Reply to
Steve

There is a known problem with the upper chain guides on that engine (2.4 L KA engine). The fix is to take off the upper guide and throw it away. Not a difficult job as the upper timing cover does not require major surgery to remove. Make sure the tensioner still works while you're in there. Btw the upper chain tensioner is oil pressure controlled & has no teeth per se.

A bad accessory belt tensioner can also make the same noise if the ribbed serpentine belt has a few chunks missing. Much cheaper fix as you don't have to take anything apart.

If it is the lower chain, then you are looking at a major job.

Reply to
E. Meyer

Can you adjust it without taking the front cover off? I remember certain Mazda piston engines, for example, had ports you could use to adjust the chain. It would be nice if I could adjust it but I think I have to take it all apart. And if I have to do that, I might as well replace chain/gears/tensioners.

Reply to
Zootal

Its self adjusting via oil pressure on that engine. If you haven't kept up with the oil changes, it (they) could be clogged. Btw - there are two tensioners, one on the upper chain and one on the lower.

Reply to
E. Meyer

According to the book I'm looking at, there is only one chain. Are we talking about the same engine? This is a K24E engine IIRC.

Reply to
Zootal

My bad. You're right. The version of this same engine in the Altimas (which I had) still had two chains in '95. It might still be worth checking the accessory belt & tensioner before digging into it though.

Reply to
E. Meyer

on 5/6/2009 4:26 PM (ET) Zootal wrote the following:

There is only one chain in the KA24E engine and it is a major job to replace. Here is a site showing some of the parts that have to be removed before getting to the timing chain (with pictures).

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"0814.The shop will probably charge from $700 and up to do the job.

Reply to
willshak

Very nice write up! That doesn't look bad at all. With some luck I won't have to drop the pan - the manual I have says not to, so we shall see. The chain set costs about $125, and a water pump is only $35, so with luck I can make it through this in a day or less for less then $200.

Yeah, right....doing the timing belts on my wife's car was close to $1000 when you add the towing bill, water pump, all of the stinkin' overpriced pulleys that don't come with the belt set, fan belts, a vise because you can't compress the belt tensioner any other way, a couple of hot dogs, a case of Mt. Dew, and a few choice words that I would not want my children to hear me say...

Reply to
Zootal

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