Metal rattle under valve cover (not top guide)

[Nismo1182]

I have a KA24DE with 80k miles on it. It makes a weird metal rattle like if it had a broken top timing chain guide. But its not that since I personally removed it. Its not the water pump or any of the accesories. Its definately coming from under the valve cover and barely gets louder at higher rpms.

I just want some ideas on what it could be. Worn timing chain and guides crossed my mind but at 80k miles?!

Oil is changed every 3500 miles with regular Mobil 10W30.

[Thee 240sx Owner]

Sure its not the chain going bad dufus.. have you checked to see if you dropped a socket in there from working on it last time.. lol Kev you know i love you.. i think ... haha idk really... bad chain is the only thing that crosses my mind

[12er]

exhaust manifold heat shield bolts..those might be loose..

[Nismo1182]

Nope, this is definately coming from the motor. Plus I removed the heat shields a long time ago.

[s13EastTN]

probably timing chain. My "70k" motor has timing chain problems. (hopefully)

[ShifDown96240SE]

I have a metal clanking/rolling sound in my valve cover, but so does everyone i know with the KA, my old and new engine both have it, and it never seemed to cause any problems

[Scott McLellan]

I was wondering where to get a timing chain set. I think I remember a company called ?TCI? or something. I also remember someone recommending Nissan OEM parts. Does Nissan sell a kit? What other things like water pump should I replace while I did it? Thanks!

[Nismo1182]

Timing chain set, timing chain guides, water pump, new belts (if old are worn.

[kool-aid54]

I think I got the same problem with my SOHC KA. I only hear the noise when I rev it up to 3000rpms but you don't hear it until then. My friend told me that a lot of 240s do that and that theres a 75% chance its the timing chain tensioner. To me it sounds like a valve floating around or something. My old 78 chevy pickup truck use to make the same noise my 240 is making when it would get low on oil which was the valves and such starving for oil. Do the SOHC's have a problem with the rockers loosening up?

[12er]

not too clear on Quote »" I only hear the noise when I rev it up to 3000rpms but you don't hear it until then"[/quote]being that the sohc KA runs hydraulic lifters, low oil can give you valve ticks as well.. are you losing oil somehow on the block?

[TrunkMonkey]

I have a KA24DE with 80k miles on it. It makes a weird metal rattle like if it had a broken top timing chain guide. But its not that since I personally removed it. Its not the water pump or any of the accesories. Its definately coming from under the valve cover and barely gets louder at higher rpms.

I just want some ideas on what it could be. Worn timing chain and guides crossed my mind but at 80k miles?!

Oil is changed every 3500 miles with regular Mobil 10W30.

have you removed the bottom guide?

-demetrius

[Nismo1182]

nope, where exactly is that.

[s13EastTN]

on the front of the engine, down next to the bottom of the chain.

this might help http://www.240sx.org/links/ins....html

[_/_/_/M aurice]

Mine does it too, but meh, if something breaks I'll just get a new motor anyway...

Although, just for ****s and giggles I might just start taking stuff apart...

[mello88]

My 92 does this also. It's a horrible rattle at startup, that seems to disappear with revs (although its prolly still there, just can't hear it). The other day I tore off the valve cover and ditched the top guide, but that didn't help at all. And by doing so I found out that the prev owner stripped the vc bolt hole nearest the TB (frontmost, pass side) so I'm sure I'll have a nice oil leak there soon.

I can only hope/think it's the timing chain. What a PITA

[Naro182]

i had the exact same problem...

ticking at start up, at idle it was loud, disappeared at higher revs...

The Culprit? you guessed it, the timing chain. I wouldnt wait any longer id replace that...

[TrunkMonkey]

nope, where exactly is that.

i'm not sure what happened, but i could have sworn that i posted the answer right after you asked. oh well...

the bottom chain guide is behind the upper timing chain cover.

1. remove the valve cover.2. set piston 1 to tdc on it's compression stroke.3. remove the distibutor.4. remove the upper timing chain cover.5. remove the bottom chain guide. it's located under the exhaust cam.

-demetrius

[BadMojo]

the bottom chain guide is behind the upper timing chain cover.

1. remove the valve cover.2. set piston 1 to tdc on it's compression stroke.3. remove the distibutor.4. remove the upper timing chain cover.5. remove the bottom chain guide. it's located under the exhaust cam.

-demetrius

That's how I'm spending a portion of my morning tomorrow (as long as the stupid rain stops). I'm also going to replace my upper tensioner, which will hopefully solve the whole problem.

BTW, Nismo, somewhere around here is a picture of what the cams should look like when cyl #1 is @ TDC on the compression stroke.

Edit: Hey, the cam thing is a sticky in this very forum. Imagine that!

[w1ngzer0]

I think I got the same problem with my SOHC KA. I only hear the noise when I rev it up to 3000rpms but you don't hear it until then. My friend told me that a lot of 240s do that and that theres a 75% chance its the timing chain tensioner. To me it sounds like a valve floating around or something. My old 78 chevy pickup truck use to make the same noise my 240 is making when it would get low on oil which was the valves and such starving for oil. Do the SOHC's have a problem with the rockers loosening up?

I only hear this rattle noise when i first start my car. I am sure i will still hear it after i do the timing chain. I am having new valve stem seals installed so mabie there is something loose. I am doing this in a month or so.

[S13_405]

.... I am sure I will still hear it after I do the timing chain.....

Yeah because I changed the timing chain, timing guide (loose side), crank shaft sprocket, almost everything in the front cover. And I cant adjust the valves because i have a 89' SOHC so i have no idea what's making the ticking noise

[w1ngzer0]

my problem could be related with my marble problem.