Z22YH Rattle/vibration at 4000rpm....

[yayoboy]

As title, no rattles that I can hear at startup, but bang on 4000rpm distinctive, quite load rattle, above and below nothing? The car has done 80k, and has had the chain done at some point prior to my ownership as it has the revised tensioner, plus I had the cam cover off once I got it home from buying it and the chain looks ok/tight. Regardless of this I was going to get the winter out of the way and change the chains as a matter of course, but the question I'm asking is could this rattle at 4k be pointing to the chain/balancer chain, and that I should change them now, or something else? Thanks in advance, sean

 

[Matt]

Could it be the heat shield resonation / rattling at that specific RPM?

 

[yayoboy]

Checked that mate, I pretty sure it's the balance chain, just hoping someone has had likewise symptoms to compare against.

 

[evocarlos]

i've done a zafira b in the past with 75k on that had a stretched balancer chain
not sure on the vibration are your engine mounts ok ?

 

[yayoboy]

Yes mate all mounts are good, does the balance chain give the rattle at 4000rpm if stretched?

 

[yayoboy]

Also, has anyone ever found a need to change the balance shafts also due to chain issues....

 

[vocky]

yes, I have found more and more balancer chains failed on otherwise quiet cam chain engines

 

[yayoboy]

Agreed, I'm gonna get the covers of at some point over the next couple of days and take a look then get the kits ordered. Vocky, have you known the shafts themselves fail due to stretched chains?

 

[vocky]

the shafts are quite robust, so are the bearings. I have seen them with no tension and the shafts were fine.

It is a good idea to replace both the chain kits, the cam chain kit has to be removed to access the balancer chain. Also worth replacing the crank pulley oil seal whilst it's apart.

 

[yayoboy]

Thanks again mate, yes I will definetly be replacing both chains, and agreed with the crank seal oh well, I was going to do it next year, but the siggy wants it now lol

 

[vocky]

what the car wants, the car gets

 

[yayoboy]

Lol ill hopefully be doing it sat ill keep you updated how it goes or if I need any advice? Thanks vocky

 

[yayoboy]

Ok about to start the chains, couple of qs, firstly, just to confirm, when I'm done, if all has gone right, I should have no chain rattle at all, even on cold starts? Secondly, once chains are on and engine is ready to fire, is it best to disconnect coil and turn engine over to build up a little oil pressure or just start as normal and let it Tickover a while? Thanks all, sean

 

[evocarlos]

once new chains are fitted balance and main chain the only noise you should hear are the injectors ticking
i leave the rocker cover off and once done turn the engine over till i see oil on the chain and the cams to be sure the oil pressure is there
then finish putting all the last bits on and then run till warm

 

[yayoboy]

Thanks Carl

 

[yayoboy]

Is it normal for these to have a bit of 'mayo' in the camcase breather pipe that goes to the tb? Please don't tell me head gasket needs doin :/

 

[Matt]

Is it normal for these to have a bit of 'mayo' in the camcase breather pipe that goes to the tb? Please don't tell me head gasket needs doin :/

Yes, especially if you are doing lots of shorter trips.

 

[evocarlos]

at this time of year i would be concerned if there was not any in these engines thats how common it is lol

 

[yayoboy]

thanks matt

 

[rushy]

How did she go m8?