Timing trouble?

Arrrrrrrrgh, I bought a x Reg micra 2 weeks ago and it sounded silent as a mouse... Now it sounds like a diesel van until it warms up! I have replaced the plugs but nothing has changed.
Is it possible I am unlucky and the timing chain needs replacing just by Chance or maybe the dealer did something to silence the problem for my test drive? Or maybe it's not the timing kit at all?! Please help
 

frank

Club Member
a chain should,nt wear like that in 2 weeks michael, it usually takes years and only for the 1st few seconds at first, can you post up a vid from close up ?
 

frank

Club Member
what a racket ! its hard to define tho tbh, can you zoom in more and move around the engine bay michael ?
 
This is the only video I can post at the moment as the engine is hot now and when it is hot it does not make the horrible noise!! I just cant understand why this would suddenly start happening :-( from cold right up to hot then nothing.
 
It sounds weird. Also think a more detailed vid would be nice. As for a guess right now maybe the plunger that spans the chain broke? Think I saw that somewhere before on here.
Can always take of rocket cover and take a look if ur handy.
 
well i'm just thinking here it could be saomething else ofcourse MM and ons second thought an engine getting warm wouldn't fix that...............
So best bet is still another vid with more positions and closer to the engine
 
I know mines is deffo the chain, mate had exactly the same noise and he changed the chain kit and it fixed it.

Cold start always rather noise for a second or 2 then back to quiet so im stumped as towhat could be causing the noise in that video
 
ok here is a more in--depth video... the noise is DEFINATLY coming from the timing kit end of the block! it is still there when the engine is revved but not as prenounced so I rekon its likely to be timing?? what do you think?
 

frank

Club Member
why would i do that, would it be to absolutly determin that the chain is the problem?
yes, mine developed a mad rattle when the tiny oil gallery to the lower tensioner blocked up, and when i removed the cam cover and ran it up you could see the cams jittering back and forward at idle, then as i raised the revs it quietened down a bit
 
how did you fix this?? it is possible, the oil is very dirty- i intend to change it asap. I dont suppose you took any pictures orhave a diagram of the blockage? and did clearing the blockage fix the mad rattle
 

frank

Club Member
i had to fit one of my spare engines in mate, then poked the hole and re-assembled it, i posted it in the "what did you do to your micra today" thread, cant find it tho
 

Enuo

Glorified Electrician
Could be the exhaust manifold blowing, get a piece of tissue and hold it around the manifold and exhaust joints in the engine bay see if you see any movement that could indicate a leak. Usually leaks are more apparent when warm however :)
 

skymera

Brutal Honesty
I did 20,000 miles on a knackered chain!

I wouldn't say its urgent. But defo get it done.

Sent from my HTC One using Tapatalk
 
That's good to know thanks I will be getting it done next week because I love my little car and if I wanted a vehicle that noisy I'd have bought a tractor
 
how did he diagnose that outcome? not saying its not just would like to know what he did to determine the timing kit is gone for future reference:)

Cheers
 
It was a combination of all the symptoms and a keen ear for engine noises. He actually thinks because the problem was sudden that it is likely to be the tentioner which has failed.
The main symptom is a
Loud clacking noise which is better when the engine is hot but still noticeable.
Exhaust is fine, plugs are new, all aux equipment and belts are OK,
And the noise is definitely coming from the chain end of the engine, near the bottom.
Hope this helps
 

pollyp

Club Member
both tensioners rely on a good supply of high pressure oil through tiny orifice in the block which hydraulically pushes the sliding shoe outwards against the timing chain to apply enough tension that stops it flapping about.

if at any point the oil gallery were blocked by thick sludge and/or unfiltered foreign objects from lack of service (very old abused oil, clogged oil filter allowing unfiltered pressurised sludge to bypass the sprung relief valve and straight into the tiny oil galleries), oil pressure can't get to the tensioners so they remain completely unloaded against the fast spinning chain. this means the loose chain and the tensioners can just rattle/flap about uncontrolled and creating alot of noise, probably more wear/tear and more risk of skipping a teeth.

the upper tensioner features a progressively stepped stopper ratchet mechanism which is suppose to mechanically stop the sliding tensioner shoe from being pushed back afew mm from where it was resting but there's a limit to how far the tensioner can be extended before the ratchet stops working.

the lower tensioner is simply a lightly sprung sliding shoe without the stepped ratchet stop and relies on oil pressure. it has a limiting notch to prevent it sliding out too far.

if the chain is so severely stretched that the tensioners reached their travel limit, unable to apply anymore tension and making it rattle, it's time to either replace/rebuild the chain or swap engine.

a slight chain rattle for the first few secs during cold start is normal cos there's not enough oil pressure yet.
after bout 5sec the oil light should be off and it should get quieter.
if it still rattles badly then either there's no pressure reaching the tensioners or the chain is really stretched.

I suggest removing the side timing chain cover to see how far the upper tensioner is extended and if it feels really loose/sloppy.
- if its not fully extended and it feels snug against the chain then it could be lack of oil pressure reaching the tensioner.
remove, disassemble and overhaul/flush the upper tensioner assembly clean. check if the face of the tensioner shoe ain't worn down to metal. then poke clear the oil hole in the block with a pin to unblock it from sludge. reassemble, new oil & filter, prime oil system then start her up.
- if its fully extended and/or feels loose/sloppy, the chain could be worn and needs replacing or engine swapping.
 
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