The crazy knocking noises

[Festiva GTX]

1989 Ford Festiva EFI with 97' Ford Aspire engine. Auto.

I just installed the 97' Aspire 50k approx miles on it engine in 1989 Festiva.

When start up the engine and run on Idle, it make loud knocking around at the head valve cover but for few seconds it disappeared but in other seconds it come back like on and off.

But never heard any knocking when driving or press little gas more?

I tried to test by pressing down all roller rockers, all them are very stiff.

It supposed Aspire engine are more noise engine than 1988-1993 Festiva engine? If it not, what the cause could be?

Timing set perfect as 10 BTDC.

[ejp2fast]

With sufficient oil, it may take a little bit for the oil to get up into the valve cover..
the EFI engines have hydraulic lash adjusters, so oil is very important.
has this engine been sitting for awhile prior to installation? if you just installed it, give it a little bit of time to see if the ticking goes away.

[miami man]

is it a knock or ticking sound?

[Festiva GTX]

is it a knock or ticking sound?

I can't be too sure which one knocking or ticking.

But engine do running smooth at idle but just very noise at idle only.

I will try record video/audio in late afternoon and post on youtube.