Timing Chain On '99 Sentra 1.6 L Engine

On 27 Oct 2006 18:00:00 -0700, "al" graced this newsgroup with:

*usually* you won't hear a chain going bad, (unless you have links that snapped, which is highly unlikely), more often the tensioners wear out and you get slop in the chain which, eventually can make the chain jump a tooth and throw your timing off.

I guess the slop could be bad enough that you could hear the chain slopping around but that would be *after* the engine warms up, not just when it's cold.

Can you describe more about the sound? Any idea from what part of the engine it's coming from? Does it happen when you start the engine after it's been driven? Does it happen all of the time? Have you opened the hood and listened while someone else started the car?

I have a 1999 Altima (110,000 km) that has always had a tapping sound for 1 or 2 seconds after I start it, usually only on warm mornings when the car has set overnight. I've never been able to figure out what it is, but the dealer suggested it might be a hairline crack in the exhaust manifold; apparently that was a common problem with this era Altima. Whatever it is, it hasn't gotten any worse in over 2 years of having had the car, so I've just learned to ignore it.

I did have the valve cover off this summer to replace the gasket, and everything under there looked brand new; no scoring on the cams, no sludge, and the timing chain was tight and looked to be in great shape, so that helps me sleep at night ;)

Hope that helps!

How many miles are on it?

Thanks for the helpful comments. The car has 99,000 miles on it. I've just noticed the sound but I've only owned the car a few weeks. It appears to happen just for a second or two when starting the car when cold. I will make a point of determining if it occurs when the engine is hot. It sounds like a mild scraping sound. It certainly would be consistent with a hydraulic tensioner just before getting oil pressure. It end abruptly as the engine starts.

Am I correct that there should be no such noise whatsover if the tensioner is operating correctly? Thanks again to all.

Al

snipped-for-privacy@home.com wrote:

On Sun, 29 Oct 2006 10:10:41 -0500, Steve T graced this newsgroup with:

agree.

I wouldn't get too excited about it...

Try using a Nissan oil filter next oil change. Some of the aftermarket oil filters don't have an anti-drainback valve appropriate for Nissans. That valve prevents oil from completely draining back to the pan when the car's sitting overnight. This will cause the funny noise when starting up.

CD