a pain in my engine compartment

[Moose]

after weeks of pain and suffering a few months ago to get the bronco running, the whole top end of the 400 was rebuilt (the blown driver side head gasket was my motivation). this saturday, the moose bent two push rods from cylinder one. can i just replace the two push rods? i've heard i may have also:

1) pushed the rockers down into the cam location

2) bent a valve also

3) scarred or even cracked a piston

and/or 4) bent a valve guide

what usually causes a bent push rod? is it a gradual thing or does it happen instantly? it started saturday night. i wanted to hear the pipes ring a little upon returning home (it can echo really loud in between the old tall buildings). it missed some when i drove it home that night. but that doesn't mean i did any of those things above. it just means pressure is being lost through the lack of spring from the missing push rod. it was mainly just a loud ticking/tapping noise.

[robertf03]

how long was the engine sitting since you last started it?

[Moose]

i've been driving it weekly since i bought it this last december. during the summer months, i had Mobile One 20W-50 Full Synthetic. i figured with the additional heat that the 400 puts out, the oil would break down by the end of the my regular 3k oil changes (and i used to think it had bad oil pressure, but turned out to not be the case). but it only got 1k with this oil in it. and i haven't changed it since the cold weeks have been here. but i'll go down to the new Mobile One 5W-40 Full Synthetic Work Truck oil as soon as this is over with. why?

[Graystroke]

Yes, did you check to see if any valves were stuck before firing it up? Only other thing is that the parts are mismatched...wrong length push rods, or piston to valve onterference. If you reused all that stuff from before then I don't know..is the cam, pushrods, lifters OEM? Yes you can replace just one pushrod. yes you can replace just one lifter... have to break it in properly, no you can't replace the cam and use old lifters unless they are roller. Hope that covers all the scenerios.

[Moose]

update:

replaced bent push rods with new ones. everything seems to be fine. had an initial off-pattern bumping. after it warmed up, everything went away. pulls like a bull again. i'll do a compression check another day this week to confirm no other dammage, however, runs fine :rolleyes: . just want to mention, the push rods were bent on the rocker arm end, not the roller rocker end. and yes, everything is oem.

[Chadnutz]

Oil doesn't lose it's ability to lubricate. It merely gets contaminated. People run filters that separate particles down to the single digit microns so they can run their oil for 10s of thousands of miles. When they do this they change the stock and bypass filters more often and have their oil analyzed. You can run Mobil 1 at least to 5k. I chance my dino in the stroke as 5k as per the owners manual. Don't let the oil companies fool you into buying more oil than you should.

[Moose]

i don't know what it is about fathers and their "sayings." but he's got in my head that 3,000 is the magic number. sure, you can change it every 50 miles if you want to, but i wouldn't let my engine even see the daylight of 3,001 miles on any 5 or 6 quarts of oil... no matter how much money you're throwing away on expensive brands of oil. you know where this is leading. my basic concern is: i don't know what this engine's been through but it seems every wearable part has begun to hit its max life after i bought it (gaskets, bushings, seals, etc.). if i can control the oil, i'll at least know it wasn't the obvious before i begin to tear into it. i really didn't want this to go here, so...

as soon as i get to work, i'll post pictures of the bent push rods... wow. those things are awesome. bent perfectly like they were mandrel bent. one looks like it was bent in two different directions, the other bent right at the center, scratches and scars all over them. :beer:

[Moose]

cylinder #1

[StevenAg03]

almost looks like a pair of slim-jims :flipoff2:

[bburris]

The one on the left looks like mine:

[texasxj]

the rods on my old 283 were just bent on the tip about 1 inch down looked pretty cool-not really!!