I have a lifter (#6 cyl exh) that wont seem to stay adjusted on my car(sig). I can adjust it and the tapping goes away for the most part and then a few days later it will be loud as ever. Last saturday i adjusted it and it was quiet for a few miles then i could hear it tapping again so i figured that the lifter is bad and i would just have to replace the lifters, i drive it like 160 miles to and from College Station for school stuff, and it is running really bad, so today i pull of the valve cover/rocker arm and find that the pushrod has been beaten to hell; i put it next to one of the other pushrods and it is aprox 3/8" shorter than it is suppose to be. It has never beaten the pushrods like that before, i have had the ocasional bent ones/ broken, but never this. I have stock pushrods and am wondering if i should have hardened ones. I dont know if the lobe on the cam is flat, the lifters are bad, or possibly the springs are bad. When i did the rebuild everything was bought to match the cam(springs, lifters). anyone got an idea?

 

are you using poly locks? they're hard to get to stay locked down if you odn't do it right. just a WAG but i'd say your push rod was caused by the rocker being too loose. check lift with an indicator. my guess is if the lifter is bad it's because you over adjusted the valve lash. do you get oil out the push rod hole?

 

yes i do use the lock nuts witht he allen head in the middle to lock it down. i thought i was doing it correctly but i may not have. i would back the lifter off till it tapped then slowly tighten until it went away, then give it another 3/4 turn, then lock the center, then snug it with the 5/8 a lil more if it would move any. i am getting oil out of the pushrod hole. this is the first time i have had to adjust the lifters in almost a year, so i dont know what the problem is.

 

hmm anyone else?

 

I bet you have a worn lobe on the cam. Valves don't usually come out of adjustment espicially with polylocks for nuts. The reason for it coming unadjusted and beating the push rod to hell is the lifter and the cam wearing causing excessive clearance for hte pushrod. Then it gets beat to hell. I have 2 suggestions:

1)pull the drain plug and look for shavings you should find a lot

2)remove the rocker, put in a pushrod and hold hte end with your finger and have someone just bump over the motor. If hte pushrod doesn't move much I'd say time for a new cam and lifters.

Good Luck!
Jay