I've been working on the timing lately and have noticed a mild tick from the valve train. I can hear it better when I remove the oil cap. I've heard a lot worse, but it is maddening because as I keep adjusting the timing to optimal I'm not sure while driving if I'm hearing the tick or detonation pinging.
The '78 250cid is the factory original engine with 43k miles on it, 2500 of which I put on since I bought it in 2011. It's had four oil changes since then and sat a few years while the project was on hold. There is a leak on the rear main seal that leaves a spot on the garage floor when parked, but I have yet to need to add oil between changes.
I use the bigger Wix filter and fill it with Joe Gibbs Driven HR6 10W40. But although it has storage protectants in it, there does not seem to be any detergent in the oil.
I've seen people fix their lifter knock after a 5min flush and oil change with Liqui Moli or Motor Medic, and some even using ATF and 100 miles. It sat for decades in the past and there may be quite a bit of sludge that is gumming up the lifters. But with my main seal leak, I'm concerned a flush may open up all my gaskets and seals to leaks, or worse yet even cause it to burn oil. Not sure that is worth it to get rid of a mild tick.
I am about 1000 miles into the next oil change, and may just do it at the 3000 mile interval instead of waiting for the end of the year or 7500 whichever comes first. A that time I could use Risoline engine treatment or Marvel Mystery Oil to replace a quart to try to cure any dirty lifters? Or I could supplement a quart with a high mileage oil which has detergents and gasket/seal protectors?
It may only be a need to zero lash the rockers. But I have also seen someone use carb cleaner on the pushrods after removing them to clean them out, then sprayed down the rod into the lifter clean that too before re-oiling the rod and lashing them all down, then run the engine a few minutes before changing the oil? Then again, with the valve cover and side covers off, it's ridiculously easy to get at the lifters, so I could just clean them individually to be sure they are not gummed up?
Anyone got any tips or tricks they use?
