Help with Timing Chain. How/what to check?

SuluR

SuluR

Buy & Sell Member
Ive been searching through countless threadsabout timing chains for a few months and i thought id ask.

Basically my SR is rattling away at 80'000 miles. Not so much in low revs, but in high revs you can definalty hear it. It isnt a constant rattle, its more like a : crr...crr...crrr and it gets faster as you rev up lol!

I had the rocker cover off to check the chain, but to be honest, i didnt know what i was looking for, or looking at. but the chain seemed ok (the bit i could see)

I understand thers two chains, and i think the noise may be coming from the buttom chain.

How do i check the buttom chain? i know the cost o a new chain is dear so some advice in simple checks or even FIXES would be great!

Im sorry for bringing this up as i know it has been talked about time and time again, and also apologies for my poor sound effects.

Any help will be greatfull

I know some people say it will be fine, if so, the sound is still annoying:p

Thanks
 
you can accurately check the chain wear by turning the engine backwards a few times to expell the oil pressure from the tensioners, and then see how many notches (on the crank pully) that the crank will move without the cams moving (ie, the amount of slack/backlash).
3 notches is normal on a well used but quiet engine, 5 notches would indicate a lot of stretch :eek:
 
Is this on the top chain?

I dont mean to be anoosence, but could you do a step by step list?

so far i assum its:

1) Remove cam cover
2) put it in gear and push it back?

I think im lost from here.

Thanks for you help!
 
this will show the total slack in both chains, pic shows the hydraulic tensioner on the lower chain, you can see the top tensioner with the camcover off, and you will see that the residual oil pressure will be keeping the chains tight.
but if you turn the engine backwards (socket or ring spanner on the crank pully) the tensioners will get pushed back by the chain running backwards and the chains will go slack (you will be able to flex the top one up and down by about 10mm)
once the chains have gone slack, you will be able to see how many notches (the 5 notches on the crank pully) the crank will turn without turning the cams :)
http://www.micra.org.uk/attachment.php?attachmentid=13602&stc=1&d=1254080506
 

Attachments

  • PICT0186.JPG
    PICT0186.JPG
    101.1 KB · Views: 1,115
Thanks for that frank, Really appreciate it. ill have a look at it tomarrow. this can be done by just taking of the cam cover? i know theres a cover on the side aswel.

Thanks again
 
SuluR said:
Thanks for that frank, Really appreciate it. ill have a look at it tomarrow. this can be done by just taking of the cam cover? i know theres a cover on the side aswel.

Thanks again
Click to expand...

yes mate, just the cam cover (you can see better with the side cover off, but the engine mount restricts access to one of the bolts :doh:)
my old super s top chain looked ok btw, till i turned the engine and came to a link that was hanging by a thread ! (that was making a ching-ching noise that did,nt dissapear if you revved it)
 
Did u manage to fix that link? while it was on? and i my noise doenst go away with rev TBH, just the engine noise takes over, if you get me.

Thanks for you helop frank, much appreciated.

BTW, if ou have any more pics, it would be alot of help.

Thanks
 
SuluR said:
Did u manage to fix that link? while it was on? and i my noise doenst go away with rev TBH, just the engine noise takes over, if you get me.

Thanks for you helop frank, much appreciated.

BTW, if ou have any more pics, it would be alot of help.

Thanks
Click to expand...

i fitted another top chain (1/2 hr job, bottom chain is a 1 day job :eek:)
and i can only find the 1 pic i,m afraid :wasntme: (testing the viability of using a chain with 2 links removed, and no head gasket)
http://www.micra.org.uk/attachment.php?attachmentid=13603&stc=1&d=1254083026
 

Attachments

  • PICT0194.JPG
    PICT0194.JPG
    107.9 KB · Views: 5,716
Thanks frank.

Say i find my top chain to be the fault, whats the process in changing it?

I know you said the bottom chain, to get to it you need the engine out, but is it the same for the top?

Its a long process changing chains, but is it managable?

Sorry for all the questions

Thanks!
 
you only have to remove the idler bolt and a sprocket bolt to change the top chain (and time the cams up), the bottom chain is a major engine strip tho.
my ss top chain was shot at 100k, and the bottom one was still ok at 132k :)
 
thanks for that frank.

Your help is much appreciated. I think sometime in the near future i will be changing the chain. If its not to much trouble i probably require your help through the forum.

Another question, where can i get a top chain from? and/or any other bits needed. Ive seen on ebay the full kit for 100 pounds but i doubt i need the whole thing.

Thanks
 
i would only use nissan chains personally, you should be able to pickup a servicable used on on here, i would have thought :)
 
Thanks for your help so far frank.

Took a few pics of what i saw. I just took off the rocker cover and took pictures.

What do you think.

IMG_0033.jpg


IMG_0037.jpg


IMG_0036.jpg


IMG_0034.jpg


apologies for the crappy cam
 
To be honest, i didnt want to touch anything until i was sure what exactly to turn! which one and which way do i turn it
 
But how do i get to the crank pully? is that by taking off the black cover?

I apologies for being abit dim:S:( im clearly not the mechanic i thot i was!
 
the big pully that your belts go on
turn the nut holding this on
if you take the wheel off its right in frount of you
 
****! i think i done it wrong.

I managed to figure out what to turn backwards. Done it with the rocker cover off. I noticed that the chain slacks abit, then tightens up again.

I took photos of the slack but i didnt check the markers!, to dark now, i think ill have to do it tomarrow.

Heres the pictures anyway. Probably useless:

IMG_0041.jpg

IMG_0042.jpg


Also. I noticed the rattling is coming from lower down, not right at the top (rocker cover). Im not 100%.

Is there a way i can pinpoint where the noise is coming from?

THanks guys
 
I finaly got the time to check mychain.

I followed your instructions frank, and i found that the lower chain starts moving at 3 nothces, but the cams (top chain) doesnt start moving until the end of the fourth chain.

Does this mean that the bottom chain is ok, but the top chains stretched? becuase i could see after 3 notches the lower chains moves, but the top chain has to tense up again.

Thanks
 
4 notches in total does,nt sound too bad, i hav,nt got a spare engine assembled to test the chains separately tho like you did, i,ll try it on mine when i get time :)
 
SuluR said:
okay, thanks for that frank.

So what are the other possibilities for the rattling?
Click to expand...

chain guides or tensioners that have worn down, through to the metal base ?
crank journals ? (tho they would rattle really bad on startup, then quieten down a bit when the oil pressure pics up)
valve/shim clearance ?
and i have used a big screwdriver against my ear in the past, to pinpoint a noise :eek:
 
I did try that but the screwdriver was long long enough. I shall try to find a long enough one and let you know what happens.

BTW the other possibilities of the problem, how easy are they for repair? and cost.

Thanks frank
 

Attachments

  • PICT0248.JPG
    PICT0248.JPG
    105.6 KB · Views: 964

Similar threads

A
Timing chain
Replies
8
Views
3K
AugustWest
A
C
best way to check timing chain..
Replies
18
Views
291
CMF_plattsy
C
3
Timing Chain Preventative Work - how much & how risky to leave?
Replies
10
Views
1K
davyboy
davyboy
Beat_Up_Micra
How to measure timing chain tensioner
Replies
1
Views
3K
frank
frank
B
timing belt or chain?
Replies
6
Views
20K
James
James
Back
Top