Broken camshaft??
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Senior User
Joined: Oct 2003
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From: Joyce, WA
Broken camshaft??
After replacing both head gaskets when one blew. I put the engine back together and go for a test drive. She runs great, smooth, good power. As I pull a hill back to home BANG! Hell, even the dog jumped. Truck still running but vibrating a lot. I make it home under my own power. Pull valve covers and discover that neither of the back two cylinders have operating pushrods. In fact I can only see a broken end of one. I am afraid I broke the cam. I say this because of the above and that when I was putting it back together I had a very difficult time with one of the rods fitting into it's lifter. My theory is that the push rod slipped off the lifter, the lifter bounced out and the push rod fell in the hole vacated by the lifter. And that trying to start it once home torqued the cam and broke the rear third of the cam off. All just theory untill I tear her down. Yep, definetly getting coal from the wife this year. Merry Christmas to all.
Hotshot
Joined: Oct 2004
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From: Durham NC
I had the bottom blow out of a lifter once! All the internals and the disc like piece that came out fell down into the oil pan. Didn't hurt anything else tho...
Pulled the pan and removed the extra parts, put a new lifter in and it started right up and ran for another year until I sold it. Next owner drove it two more years.
Pulled the pan and removed the extra parts, put a new lifter in and it started right up and ran for another year until I sold it. Next owner drove it two more years.
Lead Driver
Joined: Jul 2003
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From: AKRON ohio
A broken camshaft is out of the question! The distributor and oil pump run off the back and the front is driven by the timming chain so all HAS TO BE OK! The lifters in the old Y are of the mushroom type and will only come out AFTER removal of the cam and then they drop out thru the bottom, so they should still be OK. Get another push rod and reassemble and recheck valve lash and let us know.
Kevin Bigwin
Kevin Bigwin
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From: Joyce, WA
Thanks Bigwin, for both posts. I was thinking last night about the dist. and oil drive. I didn't know about the lifters only coming out thru the bottom though. The part that worries me is this. After limping home shutting down, Dad and I tried to start back up and more metal noises(like dropping a wrench into a rotating fan blade) happened. We did no more and pulled valve covers off to see that the rear two pushrods on both sides are gone. One I can see is broken towards the top. Where could the others go?? I haven't even tried to turn engine over by hand yet being Christmas and all. I plan on pulling intake and valley cover on Monday and see what it looks like. I'll let y'all know what I find.
Hotshot
Joined: Oct 2004
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From: Durham NC
They would have to drop into the oil pan or are laying in the oil gallery. The noise may be the crank or other lifters hitting one of them. You'll need to drop the pan to fish them out. Would be a good idea anyways to be sure oil pump doesn't pick up anything. I definitely would not try starting it again until you clean out the parts. I suspect the valve lash was set incorrectly and the pushrods bound and broke when the valve spring bottomed out or it was overrevved and valve float occured. The last possibility was the valves were set so loose or the pushrods were not seated in the lifter when you reassembled the engine and the pushrod jumped out of the lifter. Check the lifter bores for scratches.
When you put the engine back together this time make sure that the pushrods turn with your fingers and don't have any significant amount of freeplay or rock when the valves are closed and the lifter is on the heel of the cam.
One other possibility if you have hydraulic lifters is that an oil galley is plugged and those lifters became oil starved and collapsed.
When you put the engine back together this time make sure that the pushrods turn with your fingers and don't have any significant amount of freeplay or rock when the valves are closed and the lifter is on the heel of the cam.
One other possibility if you have hydraulic lifters is that an oil galley is plugged and those lifters became oil starved and collapsed.
Last edited by AXracer; Dec 25, 2004 at 01:19 PM.
