F134 Tick At Idle

Hello,

I recently noticed a ticking sound from my engine at idle and now I can't unhear it. I'm not sure if it has always been there of if I just noticed it now that I fixed other squeaks and rattles. It sounded at first like it was coming from the water pump area but after using a stethoscope it sure seems like it's from the rocker arm cover.
Here are some particulars about the engine:
It was rebuilt at some point in the past. Block was machined so no serial number left
Starts, idles, runs good. Good power and no smoke
Makes about 30PSI oil pressure at 2300RPM cruise
I adjusted all the valves and no change to the noise
Spark plugs looked good and even when I pulled them

Here's a professionally produced video of the engine at warm idle:


Any thoughts on this?

Thanks,
Ken

 

exhaust leak or a lifter

 

Agree with the fellah's above.... Could be either. To me , it sounds more like a lifter ?

 

Thanks for the replies. I adjusted both intake and exhaust valves prior to the video.
I did find an exhaust leak but it was pretty far downstream. It's a M38A1, the leak I found was at the joint down near the bellhousing. I'll order a gasket and correct that since it's a 3 bolt gasket you can't get locally. I'll need to check more upstream from there. Would this sort of noise be a manifold to block leak?
As far as a lifter issue, is there much to be done about that short of a major teardown of the engine?

 

Use a piece of 1" PVC pipe and listen around the manifold area . If there's a crack , you'll here a concentrated ' Tick sound ' on the exhaust stroke. A blown exhaust manifold gasket can cause the sound, also. Did the engine rebuilder use one?
You can check for a lifter by removing the valve cover , place rags around the head and idle the engine. Then use your tube & direct it toward any of the vale train that looks a little low or loose . Either fix should not require a " Major Teardown " of the engine. I'm not that familiar with F134, but you may be able to just remove your intake manifold to R & R the lifter's ?

 

Right..... Sorry about that .

 

So can one access the lifters under the side cover ? ( # 60 )

 

Never mind my original diagnosis here , Please.
I must research before offering guess's . God help me. There are no lifters on a F134. IMO, Tappets would not make the sound in the Video. Exhaust manifold crack or Gasket leak is the sound.

 

So I took the fan and alternator belt off and the ticking stopped. Seems more like it's coming from the water pump. Thoughts? Thanks

 

F-head has solid flat tappets.

 

Maybe the belt? It happens.

If it is any of those three accessories, you should be able to locate a bad bearing instantly with a stethoscope, or even a wooden dowel pressed to the housings.

 

Water pump is dry. Turned out that the fan and pulley were loose. Previous owner for some reason used Phillips head screws to attach. After much wrestling with a Phillips bit in a 1/4 inch wrench I got them out and reattached with hex head bolts. Tapping went away. I think I got off lucky. Thanks everyone for the input.

 

That was gonna be my next guess...

Good to find and fix, with no big expense.