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Tapping Noise At Idle

engine

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#16 merther

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Posted 03 June 2024 - 01:43 PM

Hi there, in the process of sorting out another head for a swap later when complete.

My latest theory is either a valve seat is on the move when at idle but not when at speed, or the valve guides were not reamed after install and is causing a valve to stick and not close fully.

It seems to be only happening at a certain rev figure. When I turn the motor by hand to set the tappets, all is fine. At idle the noise is present and when driving down the road at 40km or more it's fine.

As above, when I watch the rockers at idle with the cover off, I can see two valves periodically not return to their fully closed positions, giving a big gap between the valve and rocker causing the noise. Valve seat or sticking stem??

Compressions are really good at cranking speed which may support the sticking valve stem theory...

Can't get hold of a bore scope to have a look, so will swap the head when I have one ready.

 Did you find out anymore about your problem? Im having a similar noise..


Edited by merther, 03 June 2024 - 01:43 PM.


#17 merther

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Posted 03 June 2024 - 06:52 PM

With the engine ticking over should I be able to see the push rods rotate? And If so does that confirm the cam followers are turning too?

Edited by merther, 03 June 2024 - 07:08 PM.


#18 PoolGuy

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Posted 03 June 2024 - 06:57 PM

With the engine ticking over should I be able to see the push roads rotate? And If so does that confirm the cam followers are turning too?

That's correct, a dob of paint on them helps you see them spinning.



#19 merther

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Posted 03 June 2024 - 07:09 PM


With the engine ticking over should I be able to see the push roads rotate? And If so does that confirm the cam followers are turning too?

That's correct, a dob of paint on them helps you see them spinning.

Thankyou





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