What are the symptoms of a bad hydraulic lifter?

[bigmanjbmopar]

Last night after I warmed up the motor I noticed a single mis at a point that seemed consistent at every rotation, checked everything electrical found a loose connector on a plug wire but still have the issue, at idle it sounds and feels like a slight mis and only when at temp not cold. I recently changed to hydraulics with new push rods, set the lash 1 turn past zero everything seems ok cruising and at higher rpm's but can't help but wonder if one of the lifters is not opening an intake valve all the way causing a mis?

Just seems weird, if I give it gas around the same time the mis is occurring it stumbles a bit but increasing rpm smooths it right out.

Other than noise what would a bad lifter feel like at idle?

 

[lewtot184]

my experience with bad hydraulic tappets is noise. your preload doesn't seem to be excessive and if the tappets aren't clacking they're probably ok. i had a cracked porcelain on a spark plug do that once before. do an ohm check on the wires.

 

[bigmanjbmopar]

Found a hole in a plug boot, fixed seems all good, between that and a choke issue all seems good. but still want to know other than noise how would you know a lifter went bad?

 

[snakeoil24]

Vacuum Gauge will show flutter like a bad valve.

 

[bigmanjbmopar]

Fluctuating reading? I'm getting 15-16" of vac not like jumps around.

 

[spcedwards214]

Knock Knock. Who's there? Bad lifter.... tap tap tap tap tap tap

 

[dieseldazzle]

If the tune items are in spec then its Compression test time. But as I always say look at the last thing you worked on when something goes wrong.....