It's not bad unless it sits a few days and it froze up last night pretty cold. Tick goes away with just a few minutes of idling (at worst it's BARELY noticeable when I rev it) and once you drive it it goes away. Would a bit of Marvel Mystery in it before I change out the oil be good?

I'm a big believer in synth oil. I use Rotella T6 on all my rigs, all old, even motorcycles (it's certified) because of how it protects (and I've seen evidence at tear down). I usually top off with aternating quarts of dino and synth to save on the old leaky beasts. Even a can of STP now and then (in the summer). Will that help? She blows no smoke at all out the tail pipe and I don't wanna tear it down. I don't need it to do long or super hard miles, but I want her to run healthy as I can.

It also has a pump at the top of the motor I think is AC? That seems to be making some noise, I don't imagine that's good, and probably bad for mileage? It almost looks like it would be hard to delete from the system though because of the belts (1980 B350 Van).

 

Try the Marvel or SeaFoam... If that dont clear it up... Then the lifter is bleeding off and will fail at some point... Just from your description....

 

I've heard some use it to break down oil sludge to correct this, you could give it a try but my thinking is this. If it was more than one and many I think sludge is an issue, only one says to me mechanical failure, possible leaking plunger or check ball maybe a broken internal spring.

Personally I would at least take the valve covers off and have a look, static and running.

 

we used to pour transmission fluid into the crankcase to clean out the lifters, I may be dating myself with this remedy but it does work as the fluid is a good detergent

 

Only bad thing about that...... It will wash all the slug down into the oil pan and plug the engine oil pick up tube.... I Got burned 2 times on that one...
But your rite.... It is a good cleaner.... And No... Your not too old.... Hahahahahahahah Mopar on !!!!

 

I agree with Bob I've seen a couple of sbm that the sludge was so bad it it was like axle grease in the lifter valley.
Pull the valve cover and take a look.