Rattling sound... - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

dr2if4ta0sx · 02-23-2002, 11:03 PM

Alright i just got my 90' 240 coupe a couple weeks back and i have been hearing this rattling noise coming out of my engine...  everytime i rev above 3000 rpm it just rattles...  does anyone know why this is?  HELP PLEASE!!! TAHNKS

*LanceS13* · 02-23-2002, 11:19 PM

I bet it's that infamous timing chain.  '89-'90 timing chains are notorious for wearing out and jumping around.  This could get expen$ive.  I hope you didn't pay much for it.

9591 · 02-23-2002, 11:45 PM

Timing chains aren't known for wearing out. Quite the contrary; they last almost forever. It's the timing chain guides and tensioners that have problems, but they usually just cause noise at idle.
A lot of people have fixed higher RPM rattles by removing loose heat shields. Maybe that's the problem in your case.

96SEChick · 02-24-2002, 10:30 AM

My timing chain rattles at idle and my heat shields rattle while driving, especially when slowing down using my transmission to take a turn (leaving it in gear losing a little speed instead of putting it in neutral and coasting).  I have a very vocal car right now!!  hehe

dosborn · 02-24-2002, 03:16 PM

i've heard that the timing chain rattles all through the rpm range.  does it only do it at idle???

96SEChick · 02-24-2002, 05:13 PM

It probably does it all the way up the RPM range, but it's easy to hear at idle because the engine's not under load.  I'll let everyone know if there is a difference in performance and engine noise after I have my timing chain job done in the next couple of weeks (getting new chain, tensioners, guides, belts, water pump, front cover gasket---semi-major brain surgery).

(Edited by 96SEChick at 6:15 pm on Feb. 24, 2002)

gh6o6 · 02-24-2002, 07:52 PM

i have a 96 and it clicks - i think it there guide, but can that be a problem ive heard that the noisew means trouble(& $$$) and ive heard that its just and annoying noise

9591 · 02-24-2002, 09:48 PM

Lemme try again. Timing chains *do* rattle, but the reason they rattle is because the tensioner isn't working adequately, which allows the chain to bounce around doing nasty things to the chain guides and other stuff. In mild cases, it's just the guides that take the abuse, and the operation of the engine isn't significantly affected, so Nissan has decided that the guides (some of them, at least) aren't really necessary, and should be removed.
The tensioner gets its tension from oil pressure. At idle, oil pressure is relatively low, so there's less tension than there is at higher RPMs, and the chain can bounce around more. At higher RPMs, there's a lot more tension, and the chain can't bounce and make noise. Unless there's something wrong with the tensioner, which happens.
A timing chain can stretch over time (long time), but not by much. The result of this would be your valve timing being thrown off by a small amount. A properly working tensioner will still keep the chain tight, so it won't bounce, and it won't rattle
Also, the tensioner might be OK, but the oil pump may not be supplying enough pressure
Summary: Timing chain rattle is not a symptom of a bad chain, but rather:
a) a bad tensioner;
b) a non-perfectly operating tensioner coupled with an unnecessary guide;
c) a broken guide;
d) a bad oil pump.
Some of the above will cause rattling only at idle or thereabouts, some can allow the rattle to continue at higher RPMs.

Whew!

dr2if4ta0sx · 02-25-2002, 09:09 PM

I have another question... besides the heat shield is there any other possibility something else is rattling, i heard somthing about the rockers in the engine... what is that and can that also be the source to the rattling sound???

musclesgabe · 02-25-2002, 11:45 PM

it could be your cat. i had this problem when i first got my car. the inside of your cat is like a bunch of hunnycomb kinda stuff and peices can break off and rattle. i'd stick your head under the car and have someone rev it up and see where its comming from. and if it is your cat then this is a good time to switch to a high flow cat! thats what i did.

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02-23-2002, 11:03 PM	#1
dr2if4ta0sx Leaky Injector Join Date: Feb 2002 Location: SoCal Age: 41 Posts: 145 Trader Rating: (0) Feedback Score: 0 reviews	Alright i just got my 90' 240 coupe a couple weeks back and i have been hearing this rattling noise coming out of my engine...  everytime i rev above 3000 rpm it just rattles...  does anyone know why this is?  HELP PLEASE!!! TAHNKS

02-23-2002, 11:19 PM	#2
LanceS13 AutoX Junkie Join Date: Jun 2001 Location: MS Age: 39 Posts: 2,044 Trader Rating: (0) Feedback Score: 0 reviews	I bet it's that infamous timing chain.  '89-'90 timing chains are notorious for wearing out and jumping around.  This could get expen$ive.  I hope you didn't pay much for it.

02-23-2002, 11:45 PM	#3
9591 Leaky Injector Join Date: Feb 2002 Posts: 122 Trader Rating: (0) Feedback Score: 0 reviews	Timing chains aren't known for wearing out. Quite the contrary; they last almost forever. It's the timing chain guides and tensioners that have problems, but they usually just cause noise at idle. A lot of people have fixed higher RPM rattles by removing loose heat shields. Maybe that's the problem in your case.

02-24-2002, 10:30 AM	#4
96SEChick Nissanaholic! Join Date: Jun 2001 Location: Broken Arrow, OK Age: 44 Posts: 1,814 Trader Rating: (0) Feedback Score: 0 reviews	My timing chain rattles at idle and my heat shields rattle while driving, especially when slowing down using my transmission to take a turn (leaving it in gear losing a little speed instead of putting it in neutral and coasting).  I have a very vocal car right now!!  hehe

02-24-2002, 03:16 PM	#5
dosborn Leaky Injector Join Date: Feb 2002 Posts: 67 Trader Rating: (0) Feedback Score: 0 reviews	i've heard that the timing chain rattles all through the rpm range.  does it only do it at idle???

02-24-2002, 05:13 PM	#6
96SEChick Nissanaholic! Join Date: Jun 2001 Location: Broken Arrow, OK Age: 44 Posts: 1,814 Trader Rating: (0) Feedback Score: 0 reviews	It probably does it all the way up the RPM range, but it's easy to hear at idle because the engine's not under load.  I'll let everyone know if there is a difference in performance and engine noise after I have my timing chain job done in the next couple of weeks (getting new chain, tensioners, guides, belts, water pump, front cover gasket---semi-major brain surgery). (Edited by 96SEChick at 6:15 pm on Feb. 24, 2002)

02-24-2002, 07:52 PM	#7
gh6o6 Zilvia Junkie Join Date: Oct 2001 Location: Dirty Jersey Posts: 550 Trader Rating: (0) Feedback Score: 0 reviews	i have a 96 and it clicks - i think it there guide, but can that be a problem ive heard that the noisew means trouble(& $$$) and ive heard that its just and annoying noise

02-24-2002, 09:48 PM	#8
9591 Leaky Injector Join Date: Feb 2002 Posts: 122 Trader Rating: (0) Feedback Score: 0 reviews	Lemme try again. Timing chains do rattle, but the reason they rattle is because the tensioner isn't working adequately, which allows the chain to bounce around doing nasty things to the chain guides and other stuff. In mild cases, it's just the guides that take the abuse, and the operation of the engine isn't significantly affected, so Nissan has decided that the guides (some of them, at least) aren't really necessary, and should be removed. The tensioner gets its tension from oil pressure. At idle, oil pressure is relatively low, so there's less tension than there is at higher RPMs, and the chain can bounce around more. At higher RPMs, there's a lot more tension, and the chain can't bounce and make noise. Unless there's something wrong with the tensioner, which happens. A timing chain can stretch over time (long time), but not by much. The result of this would be your valve timing being thrown off by a small amount. A properly working tensioner will still keep the chain tight, so it won't bounce, and it won't rattle Also, the tensioner might be OK, but the oil pump may not be supplying enough pressure Summary: Timing chain rattle is not a symptom of a bad chain, but rather: a) a bad tensioner; b) a non-perfectly operating tensioner coupled with an unnecessary guide; c) a broken guide; d) a bad oil pump. Some of the above will cause rattling only at idle or thereabouts, some can allow the rattle to continue at higher RPMs. Whew!

02-25-2002, 09:09 PM	#9
dr2if4ta0sx Leaky Injector Join Date: Feb 2002 Location: SoCal Age: 41 Posts: 145 Trader Rating: (0) Feedback Score: 0 reviews	I have another question... besides the heat shield is there any other possibility something else is rattling, i heard somthing about the rockers in the engine... what is that and can that also be the source to the rattling sound???

02-25-2002, 11:45 PM	#10
musclesgabe Join Date: Feb 2002 Posts: 2 Trader Rating: (0) Feedback Score: 0 reviews	it could be your cat. i had this problem when i first got my car. the inside of your cat is like a bunch of hunnycomb kinda stuff and peices can break off and rattle. i'd stick your head under the car and have someone rev it up and see where its comming from. and if it is your cat then this is a good time to switch to a high flow cat! thats what i did.