Pushrod Destruction Help!

[Benny-]

72 c10 with a 350 motor.

Engine has been ticking the past couple days. Pulled the valve cover off to check things out. All rocksers had roughly the same amount of thread showing but one rocker was very loose. I pulled the rocker and found the top end of the pushrod all chewed up.

I've been searching on collapsed lifters. Is that something that could cause this? How can I diagnose the problem at this point? Im guessing a collapsed lifter causing too much clearance between pushrod and rocker arm?

Thanks!
Posted via Mobile Device

[hamjet]

Off the top of my head if its an original engine with alot of miles, the tip of the pushrod could have just been worn thin till the point of breaking up at the tip. I would change the pushrod, ball, nut and rocker, (or all pushrods, balls, nuts and rockers) and motor on. Just make sure you watch the rockers with the valve covers off while runnung to make sure oil is pumping to them and you don't have any plugged lifters. I had a sbc years ago that a pushrod wore a hole right through the rocker it was so thin, many miles and poor lubrication I guess. I think the pieces that went to the pan are too large to go through the pump pick-up screen, change oil and filter...

[custom1970]

Ok, without more info this is a guess at best. But yes a bad lifter could cause this. So could a worn out cam, rocker arm stud pulling out, and the locker nut backing off. Easy fix is like said throw a new one in and run it. Bad news is the motor isn't going to last long. There's a lot of metal floating around in there. Depending on how long this has been going on, but once that steel hits a soft main bearing it sticks and the clock starts ticking. You could try pulling the pan, flushing the engine and putting a strong rare earth magnet inside the pan to collect the metal, but your still gambling. My concern would be what do the rest of the push rods look like? If its your DD I'd be looking for new engine. Sorry if I'm the bearer of bad news....

[Gromit]

Totally agree with custom1970 - jeez, I would sure like to see a photo of the (disassembled) lifter that was under that pushrod..

When I first read what you posted about the rocker being too loose I thought - wait no - too tight? But I see what you were thinking and I get the impression you know what you are doing especially when you mentioned looking at the number of threads exposed on each rocker nut..

But as Hugger mentioned (sorry if I've got his handle wrong I can't look back to verify who it was right now), anyway the oil path is as you know up through the hollow lifter and hollow rod so if anything gets clogged up it is catastrophic because the farther you go the less oil pressure is available.

When I bought my C10 I didn't trust anything and I took out all the lifters and rods - I sprayed brake cleaner through the lifter rods and a lot of crap came out of some of them - some took an alarmingly long while to finally flow freely..

But remember; a totally new GM crate motor is only $1,600 or $1,700 - and with no core you still have your motor.. so it puts a reasonable limit on how bad things can get..

[Gromit]

Doh! Sorry Dui it was hamjet... my bad

[GRX]

Agreement with what has been said so far. Also check to see if pushrod guide hole in the head has been worn. Often accompanied by a cut rocker stud.

[Benny-]

Guys thanks for replies. I've since replaced the rod. Weird thing was the top of the broken rod was stuck in the rocker when I pulled it off. I got a magnet and cleaned out all the little metal pieces and changed the oil. Im really wondering if I should put any more money into this motor (rocker arms rods lifters etc). As mentioned before, i think it's a waiting game now for a bearing to go. It's my daily driver for the most part so I think I'll just run it till it goes then replace with a crate engine.
Posted via Mobile Device

[GRX]

Sounds like a solid plan. Be sure to check all the other assemblies while the covers are off. If one is bad others may not be far behind.

[67 chevelle]

Change the oil again , and if that valve is working properly now , ill bet it is fine , use good oil or additive for flat tappet cam

buy the way jegs has a special on now 250 horse 350 for $1459 delivered

[leftybass209]

Originally Posted by Benny-

Guys thanks for replies. I've since replaced the rod. Weird thing was the top of the broken rod was stuck in the rocker when I pulled it off. I got a magnet and cleaned out all the little metal pieces and changed the oil. Im really wondering if I should put any more money into this motor (rocker arms rods lifters etc). As mentioned before, i think it's a waiting game now for a bearing to go. It's my daily driver for the most part so I think I'll just run it till it goes then replace with a crate engine.
Posted via Mobile Device

I would say not to put any more money into the motor, unless it's a complete rebuild. It's obvious there's wear, and with wear comes metal shavings and all that jazz. It get's in between the bearing surfaces and really chews things up. If you were to drop in a new cam, or heads or whatever, you just create the potential to contaminate those things with metal shavings, unless you are absolutely sure there's no extras laying in the bottom of the pan.