Over weekend, my 98SE engine starts rattling sound. Do you know what is causing this sound? I stop driving because of this for fear it will make it worse. TIA.

https://drive.google.com/file/d/1yZ_...ew?usp=sharing

 

Agree, sounds pretty bad. I would get it to a good mechanic, ASAP. How is the oil level ?

 

Check oil level today. it is at top mark, cold, Use synthetic Mobil 1 5/30 at 2500 mile. I usually change at 3500 with nissan oil filter. So it is not black.

 

Won't let me view the video but with weird engine area sound you can't determine, it's best to remove the serpentine belt and start it in park/neutral for 20 seconds. Obviously can't drive the vehicle because no alternator/power steering etc, but if you start it with no belt and the noise persists, you know it's not a noisy idler pulley/power steering pump and it's something internal on the engine

Did you check all the heat shields on the exhaust?

 

I went ahead changing engine oil to M1 5/30 with Nissan oil filter. Loosen and retighten serpentine belt. No play on idle pulley. Sound remains
You may be right, I completely forgot. Six months ago, the old flex pipe cracked. Brought in and a shop sawzall it off and welded a (oreilly auto part) replacement. Will check it.

 

Not from the exhaust shield. Something internal to the engine. Had similar noise like this guy ( ).

 

Chain tension is low.

 

Maximeltman, if I have to remove/replace secondary chain tensioner, do I have to remove primary timing chain, intake cam sprockets, secondary chain, in that order? no shortcut right?

 

Did my homework. There are 4 chain guides and 3 chain tensioners. My luck would come if primary chain tensioner (one behind the plastic black cover) fails. Other than that, engine cover has to come off in order to have all guides and tensioners replaced. I've been searching on timing marks ( ) and replacement kit, $140, .

Pulling the engine cover is an intensive task, perhaps a weekend task:
Release fuel pressure, run engine, pull fuel pump fuse. Disconnect battery.
Drain/save engine oil and coolant.
Remove intake manifold (and any parts blocking it)
Remove both valve covers, remove coil packs, loosen spark plugs to help turning crankshaft.
Remove serpentine belt tensioner mechanism, RH engine mount after proper engine support, power steering belt/pump. Does AC compressor, alternator have to come off too?
Remove camshaft/crankshaft sensors.
Remove crankshaft pulley bolt, remove/pull the pulley.
Remove lower oil pan and 2 bolts holding engine cover.
Remove 20 bolts/nuts holding engine cover following correct removal sequential order.
Pry engine cover open.

LINING UP TIMING MARKS. Use crankshaft bolt, turn crankshaft to line up all timing marks.
Primary chain - line up marks on crankshaft sprocket and on 2 intake cam sprockets.
Secondary chain - line up colored chain links on exhaust cam sprockets.
Compress 2 secondary chain tensioners and hold it with paperclips.
Loosen cam (int/ext) sprocket bolts while holding int/ext camshaft with a wrench. (optional, maybe)

Compresss slack side chain tensioner with paperclip and remove tensioner.
Remove primary timing chain.
Replace all 4 guides.
Replace 2 secondary chain tensioners (loosing 2 bolts holding it from valve cover side).
Replace secondary chain and ext sprockets (optional)
Replace water pump (optional)
Replace primary chain (optional)
Replace slack side chain tensioner
Apply engine oil to all new parts and where chain makes contact.
Apply RTV and reinstall engine cover
Apply RTV and reinstall lower oil pan
Reinstall the rest.

Wow, lot of removing.

 

RockAuto has this kit, which seems high quality kit (no sprocket though) and with lifetime warranty.
https://www.rockauto.com/en/moreinfo.php?pk=2779962&cc=1316803&pt=5756&jsn=106 26&_nck=jb38c6P4Fi4%2F4LYvAUbuuSXAQP008FSaoPZK097G leLojMuEerEWqRW1YRlMxACmEkjX6Pe5TeCwi11mBA40vfyyES eq3KSMUme2xDHO8E4pLoWUk9909BrsI6ycuRYS2VDqyOmfDWfN wgIzzOs%2B3gsSiCmwJuZ4029mdoWID57DuNCkHPlJLWMMq%2B ne4rGumfl3XrbxR8pHzz%2FHNQNKMjv8cYeH3F%2Fw1VESqW7p 8fluVY6J%2FlCU%2F5Ch6F9S8dLpLOLDiqZhds9rzz%2Fg3sPW jgLe6t3svQkcKvtQkI7aAe6fRspAFYMwvRSQJJ%2BWLYZiY2pZ ztq2LJ%2Fybmy01WhrJVhqWO45mPbbiPuyoLb0Jy8dHjbN71hY fFUaokLppgBpFy2CA3Li3ZY7yTqvQEHXwZvRbaNvhBgyRmrl2L k7WVccS01zwcCpMfA3DCBVbZALOO3Jrm2JrUij3tXukd90WGJr CB7m42ao&_nck=jb38c6P4Fi4%2F4LYvAUbuuSXAQP008FSaoP ZK097GleLojMuEerEWqRW1YRlMxACmEkjX6Pe5TeCwi11mBA40 vfyyESeq3KSMUme2xDHO8E4pLoWUk9909BrsI6ycuRYS2VDqyO mfDWfNwgIzzOs%2B3gsSiCmwJuZ4029mdoWID57DuNCkHPlJLW MMq%2Bne4rGumfl3XrbxR8pHzz%2FHNQNKMjv8cYeH3F%2Fw1V ESqW7p8fluVY6J%2FlCU%2F5Ch6F9S8dLpLOLDiqZhds9rzz%2 Fg3sPWjgLe6t3svQkcKvtQkI7aAe6fRspAFYMwvRSQJJ%2BWLY ZiY2pZztq2LJ%2Fybmy01WhrJVhqWO45mPbbiPuyoLb0Jy8dHj bN71hYfFUaokLppgBpFy2CA3Li3ZY7yTqvQEHXwZvRbaNvhBgy Rmrl2Lk7WVccS01zwcCpMfA3DCBVbZALOO3Jrm2JrUij3tXukd 90WGJrCB7m42ao&_nck=jb38c6P4Fi4%2F4LYvAUbuuSXAQP00 8FSaoPZK097GleLojMuEerEWqRW1YRlMxACmEkjX6Pe5TeCwi1 1mBA40vfyyESeq3KSMUme2xDHO8E4pLoWUk9909BrsI6ycuRYS 2VDqyOmfDWfNwgIzzOs%2B3gsSiCmwJuZ4029mdoWID57DuNCk HPlJLWMMq%2Bne4rGumfl3XrbxR8pHzz%2FHNQNKMjv8cYeH3F %2Fw1VESqW7p8fluVY6J%2FlCU%2F5Ch6F9S8dLpLOLDiqZhds 9rzz%2Fg3sPWjgLe6t3svQkcKvtQkI7aAe6fRspAFYMwvRSQJJ %2BWLYZiY2pZztq2LJ%2Fybmy01WhrJVhqWO45mPbbiPuyoLb0 Jy8dHjbN71hYfFUaokLppgBpFy2CA3Li3ZY7yTqvQEHXwZvRba NvhBgyRmrl2Lk7WVccS01zwcCpMfA3DCBVbZALOO3Jrm2JrUij 3tXukd90WGJrCB7m42ao

 

Yea...it's very involved. While it is possible to do this and not dropping the engine. I javen't wrenched on mine like that for a very long time. When's the last time you changed oil? Do you use synthetic(mobile1 5w30 is what I use) or reg? You might have sludge in the primer gulley( oil path to the tensioner) maybe put an oz of seafoam for every quart of oil to see if it circulates enough to break down sludge. I once contemplated cutting the engine cover near the cam gears for easier access to them. But that idea quickly faded lol. Low oil pressure might also be the pump itself. When I did my oil pump I used one from the HR variant; suppose to have better pressure. Anyways, hope you get it figured out!

 

I used Mobile1 5-30 for it and religiously changed oil every 3000-3500. Last oil change was few miles ago; I want to see whether new oil helps eliminate the rattling, it did not. I did have same thought of cam opening too. I am guessing the rattling is probably caused by bad secondary chain tensioner. The noise seems loud when hearing along the front left bank. But who knows, it seems like a bell echoing in a wedding chapel. I hope not oil pressure since it would light oil SES. After viewing several YT videos, I am thinking Nissan could've done more to improve serviceability for replacing timing chain/guide. LOL.

 

I would pull the primary chain tensioner cover off and inspect how extended it is. But I would agree that something in that timing chain system ain’t right. When my primary tensioner died it sounded worse than that. If you decide to follow through with the repair good luck to you🙏