# Something chipped? AND timing chain noise



## dabarrelman (Jul 10, 2008)

Hey everyone,

I took off my valve cover to check the timing chain area because it's making a rattling noise. When I was looking around, I seen this (see arrow in the pics). I'm not sure if it supposed to be like that or it got chipped.


















Also, I noticed my car making a loud popping/clattering noise (kinda sounds like pop corn) coming from the timing chain area when I'm in park, but it's more loud when I put it to drive and reverse (Automatic tranny) when I keep my brakes on. The chains are still good with no significant slack (Tensioner still good?). Checked the oil and there's no metal shavings. The car starts up slower than usual...
I'm not sure what's making the noise..

Any help is appreciated.
Thanks


----------



## maroonsentra (Mar 3, 2007)

dabarrelman said:


> Hey everyone,
> 
> I took off my valve cover to check the timing chain area because it's making a rattling noise. When I was looking around, I seen this (see arrow in the pics). I'm not sure if it supposed to be like that or it got chipped.
> 
> ...


do a good search. I believe these are symptoms of the tensionsors going bad, causing the timing to be off. I've read it on here before.


----------



## sentra77 (Aug 3, 2008)

its your upper timing chain tensioner. ive changed mine recently and i fixed the noise make sure to clean the area where it installs cuz it might cause a rattling noise during startup. it takes like 30 min to do


----------



## dabarrelman (Jul 10, 2008)

Cool. Did you pull out the engine to change the tensioner?


I haven't done anything to the car yet.. I'm waiting on my uncle or friend to check it out.
Hopefully it'll be up and running by nextweek.


----------



## sentra77 (Aug 3, 2008)

no theres a thread over her for it. all you need is a jack and some basic hand tools. hers the link http://www.nissanforums.com/b14-95-99-chassis/140358-step-step-instructions-upper-timing-chain.html


----------



## dabarrelman (Jul 10, 2008)

UPDATE:
Still waiting for my parts to come in...
I decided to turn on my car to keep the battery charged.
Right when the car was about to start, it stopped. I tried to turn it back on and now it can't. I'm not really good at explaining the sound so I'll post a video later on.

I assume it wont turn on because of bad timing?


----------



## etepsnewo (Jul 5, 2008)

The upper tensioner has a nylon guide on it that wears down from the chain traveling across is. When is wears down to the point that the chain will contact its metal parts under the guide it will make lots of noise at idle. The chain will also have too much slack so the timing is sloppy and may effect how the engine starts and runs. If the chain breaks your engine will get damaged because the piston(s) will hit any valves that remain open. You can check the upper chain easier than the lower chain. Is the upper chain loose? Put a socket wrench on the crankshaft pulley nut and turn the engine over AFTER YOU REMOVE THE SPARK PLUGS and/or DISCONNECT THE BATTERY and see if the chain slaps loose to tight as the valve give and release resistance from the pressure of the valve springs against the can lobes. Turn it clockwise as looking at it from the passenger side of the car.

Replacing the upper tensioner is only two small bolts on the tensioner located behind the rear sprocket/ timing advancer on the rear cam shaft. A replacement is only about $60 at the auto parts store. To change the upper tensioner you only have to remove the plate on the upper passenger side of the head. It's top edge is showing in your photo. You might need to remove the motor mount there too. I am not sure if it is in the way or not because I pulled the engine in my last two I did. Reseal the upper cover with RTV sealant. Might need to replace the valve cover gasket too.

By looking at your photos is looks like you are pointing at the lower timing chain where it goes over the top of the double sprocket. The double sprocket transfers the power from lower timing chain driven by the crankshaft to the upper timing chain that drives the cam shafts which operate the valves. I don't see anything unusual in the photo. Is the lower chain loose or sloppy? The tensioner is located on the rear side of the engine just below the water pump goose neck. It is a raised circle with wings with a small bolt on each side of it through the wings. You can replace the tensioner easy enough but to change the two chain guides that wear out inside there you have to remove the lower timing chain cover. It is behind the timing chain cover that is the front of the lower block (short block) section of the engine. The water pump is mounted on that cover. The cover spans from the head gasket to the oil pan and houses the oil pump too. The engine mount mounting bracket will have to be removed too. The manuals I have says it all can be removed for the chain and or tension guides to be replaced with the engine still in the car. I don't see how, clearances are really tight down there. I have pulled the engine/trans to do mine in both of my Sentras. (200SX).

Here are a few photos to to give you a better idea of what is in there and where.
All that varnish on Flickr - Photo Sharing!


----------



## dabarrelman (Jul 10, 2008)

UPDATE:

Sorry I haven't updated what happened.
Towed it to my uncle's house, he checked it out and said there was nothing wrong with the timing assembly.
It was actually the alternator that was making that metallic noise and the distributor was the reason why it wouldn't start.
Changed them and also replaced the timing chain assembly since I already bought the kit and it was overdue for a change.

Thanks everyone!


----------

