Ticking lifter

[the_0utsider1]

I changed my timing belt recently and while i had the car apart in my garage, i replaced the lifters also.

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With the notorios ticking and curious to the cause of the ticking, i took apart one of the original lifters.
Removing all the lifters, none were spongy so there was no air in them.

I found that oil can get into the lifter from the hole on the side of the main body or from the hole at the top of the lifter which has been made larger with new version. Both holes lead to the same area.
Oil then goes down the middle of the lifter to the check ball which i have an arrow pointing to. This check ball is the only way in and out of that area- that is without seeping through the side between the moving and stationary part of the lifter. With oil, this gap would have very little seepage.

With this i figure that when it is cold enough, oil throughout the lifter being thick makes the check ball hard to move to let in more oil to close the valve train gap. Voila- TICKING NOISE. Also because the only way in is through the checkball, oil primed into the lifter will never circulate out of the lifter. being diesel will solidify in alot colder temp, that might be why the manual says to prime it with diesel.

Also, the spring that extends the lifter may not be strong enough to overcome the thick oil to fill the gap in the milliseconds before the valve is pushed open again.

Well, I'll wait and see if my hunch is true when next winter comes around.