tapping after cam fitting

[johnny27]

I had a thread a while ago about fitting my 275 cam in a C12NZ. Got it done with the rocker removal tool. Have it back together now, but there's a tapping noise coming from the cam box. And its not lack of oil, cause its beening tapping for hours, so its not the case of the tappets self adjusting. Is it possible i could of bent a valve when compressing a valve and moving the cam while fitting it? i made sure the engine was not a TDC though.
Any suggestions? BTW the engine is pulling fine with no missing

[Adam]

Did u clean the lifters out?
Or just left them?

When i fitted mine, it tapped for about 2-3mins. Then was completely silent.

I assume yours wasn't tapping before you did the cam?

[johnny27]

i just left them in place, it was'nt tapping before i changed the cam, but it is constantly tapping now hours later. If i had compressed a valve against the piston, would it cause this tapping noise, as if the valve bent it would be making noise when lifting two and fro from the seating? Although i'm not having any flatspots or misfires which i would think a bent valve would cause from leaking compression

[Adam]

Did you use your old followers/pads with the new cam?
It could because the followers etc are worn to the old cam.

[johnny27]

Did you use your old followers/pads with the new cam?
It could because the followers etc are worn to the old cam.

Is this a common cause? Do you think its worth buying new rockers? Is it any use replacing the tappets with new ones, as it would'nt take the shape of the old cam as it is not in direct contact with them? Thanks for your help, if you think its worthwhile i would go and buy the new lifting gear today

[Adam]

Mine used to tap all the time.
I changed my cam, followers,pads.
Cleaned the lifters.
And that sorted it.

So i guess it was a worn cam and/or followers that were causing the tapping.

Was the cam new?

[mikey14sr]

The followers 'should' allways be replaced when fitting a new cam, second-hand cams should be fitted with the followers they were running with, or new ones.

[leebo]

how do you clean your lifters? i have lifters that may need a clean. also was told to compress the lifters and put them into a pucket of oil? anythin makes sence (sorry for hijack, wasnt worth a new thread)

[johnny27]

well an update. Can't thank you enough guys for the advice finnaly got it sorted. i determined that the tapping was coming from the middle two valves. So i lifted out the two rockers, and found they where badly worn in the shape of the old cam, causing to much play. I put in another two newer rockers, and its perfect now, no tapping what soever. Thank you very much, without your help i would have never ever thought of a worn rocker, cheers

[mikey14sr]

nova power, all the info you need to clean the lifters is in the haynes manual.

Johnny, well done fella.

[Adam]

i would have never ever thought of a worn rocker, cheers
Told ya ;):thumb:

Nova_power, yeah as Mikey said theres a good guide in haynes manual on how to clean the lifters. V. easy to do.

[craig green]

I find it best to squeeze the lifters dry in the soft jaws of a vice, they pump up with clean oil almost straight away then when started.

I know the problem is sorted but I would have checked for a dislodged follower. Ive done that once when using the cam in situ removal tool.