# Timing belt or Chain?



## WESIDA (Sep 18, 2004)

alright so iam new in engines and this might be a stupid question to you  . i bought a rebuilt cylinder head and iam gonna put it on. so i thought maybe while that is gonna be done i might as well change the timing belt. i called autozone in my area and they told me that my car 91 240sx DOHC does not have a timing belt, just a timing chain. is that true? 
if it is iam guessing it is probaly the blet that goes at the end of the cams/gears at the end of the cylinder head. is this right.?
do you think i should have the belt/chaing at 131 k now?

thanks alot in advance
MHB


----------



## thedaddies (Sep 29, 2003)

it's a chain on the KA24DE, and if it aint broke don't fix it.=)


----------



## WESIDA (Sep 18, 2004)

hehe alright cool that saves me some money . thanks man


----------



## little240boy (Jan 13, 2004)

Actually while you have everything open, check for chain rattle. Also check your front cover for it scratching away. Based on the year, I'd suggest to replace your timing guides and also your chain tensioner, you'll thank yourself later


----------



## Mekanik22 (Mar 14, 2005)

thedaddies said:


> it's a chain on the KA24DE, and if it aint broke don't fix it.=)


If it's starting to slap and make noise, he's better off fixing it before it has too much excessive play which means your timing changes because it takes longer to take up the slack in the chain. Or the chain can break and he'll be buying a new timing chain cover, chain, and other things that will give way when a chain spinning at 800-900 rpm snaps and smashes against it.


----------



## el tigre (Jun 30, 2005)

Are these engines non-interference engines. What I mean is if the timing chain does go will the pistons smash into the open valves or collide with anything in there way.


----------



## wil1213 (Jul 16, 2005)

el tigre said:


> Are these engines non-interference engines. What I mean is if the timing chain does go will the pistons smash into the open valves or collide with anything in there way.


I 2nd this ?


----------



## el tigre (Jun 30, 2005)

Do you guys know what I am talking about???


----------



## sunnydet90 (Sep 10, 2004)

el tigre said:


> Do you guys know what I am talking about???


 if its like anything else nissan i've owned they will bend valves in a heartbeat but i dunno for sure.

ex. 1990 sentra GA16i broke timing chaing bent 12 valves. 700 dollar fixer


----------



## 240luvr (Oct 8, 2004)

As for replacing timing chain guides. Get ready to spend some money. I have my block out getting machined right now, and I decided I should probably get some new guides. And just one of them (the spring loaded one) costs freakin' $95...$95 for a piece of plastic...


----------



## mille-16i (Jun 16, 2004)

my recomendation is you already have the front of the engine tore apart do it all now instead of lattter but heres the biggie a rebuild head on a bottom end with 131000 and 14 years on it may not be a good mix normally you donot tighten up the top end with out at least replacing the rings or they may become sacrafical items.


----------



## rogoman (Dec 16, 2004)

el tigre said:


> Are these engines non-interference engines. What I mean is if the timing chain does go will the pistons smash into the open valves or collide with anything in there way.


Yes! If the chain breaks, the valves will get bent.


----------



## el tigre (Jun 30, 2005)

Thanks a lot, though it wasn't the news I was hoping for.


----------

