Engine locking up??

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68coupe

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I am just finishing install of a 5.2 magnum engine using my old 904 transmission. First time turning the key and something locks up. I put a ratchet on the crank pulley nut and the engine will turn backwards about 1 turn and lock! then turn forward about 1 turn and lock!

I took the starter back out to see if maybe that was a problem. Nope.

If I didn't get the torque converter seated right, could that be the problem? The TC bolts went in with no problem.

If that is the problem, I gotta pull the engine out far enough to reseat the TC. Right?
 
is this a new rebuild? piston to valve clearance checked?
you can remove just the converter bolts and check engine rotation.
 
If they aren't in all the way yes,they will hit the block. Did you rotate the converter while pushing on it to make sure it went all the way into the pump before mating it to the motor?
 
No, not a rebuild. Used engine, but I checked the engine rotation while on the engine stand. The only thing other than that was installing spark plugs.

Good Idea on unbolting the TC. I guess that's the easiest thing to check. I spray painted the one elongated flex plate bolt hole and the corresponding bolt hole on the TC, so it should be easy to get it matched back up.

Well, guess it's back to the basement and working on my back for a while. I'm gettin' to old for this $h**! LOL
 
Sedanman said:
If they aren't in all the way yes,they will hit the block. Did you rotate the converter while pushing on it to make sure it went all the way into the pump before mating it to the motor?
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I read since I put it in that you are supposed to put pressure on the TC while turning it and it will make two clunks? One for the power shaft and one for the pump shaft?
 
I did that same trick! If the converter isn't in all the way it will be hard to get the trans to pull into the motor,some used to use the BH bolts to draw it in to the block which won't work if it's not in the pump all of the way.
 
Curses! I took the inspection plate off, TC bolts out, turned the motor and it still locks up. I'll remove the spark plugs tomorrow. Don't believe that's the problem. I had the distributor out, but can't see how that would be the problem. I just put the manifolds on, but can't see how that would cause the problem. I know that I turned the engine before while putting in the TC bolts.

Oh Well, tomorrow's another day for a challenge.
 
Did you drop anything inside the engine via the distributor hole? **** happens lol
 
I kept going back and forth with a socket on the crank pulley bolt and it rolled through. But there is still an obstruction there.
The crank would roll around about 270*. If it was something on top of a piston, seems it would go closer to 360*?
It stopped with #1 and #6 up. I'll stick a magnet down through the spark plug holes.
 
Rolling through it is a sure recipe for disaster. Never ever roll through an obstruction. I once saw a guy crack a block doing that.
 
I rolled through it just going back and forth with a ratchet checking to see how far it was turning - not with the starter. I wasn't really trying to go through the obstruction, just listening for the noise of the clunk to get a location. I agree with you, I wouldn't try to force it!
 
Parts like dipstick tubes, mechanical fuel pumps, can cause snags without doing any damage. Fingers crossed for you.
 
68coupe said:
I rolled through it just going back and forth with a ratchet checking to see how far it was turning - not with the starter. I wasn't really trying to go through the obstruction, just listening for the noise of the clunk to get a location. I agree with you, I wouldn't try to force it!
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Believe it or not it's very easy to do major damage even with a short ratchet. Back in the mid 80's I worked as a maintenance man at a trailer mfg and they had a little Toyota pickup for running parts. The timing chain jumped and I got the job fixing it even though I knew nothing about Jap technology. Told the boss he should buy me a serv manual cause it had several things to line up and I'd only be guessing on how it went together but he was too cheap. He bought the chain/gears/guides and I put it together the best I knew how. Thought I'd be safe and just roll it over with a ratchet and when I did I felt 4 bumps that felt like compression. WRONG! With a 3/8 ratchet and very little effort I bent all 4 intake valves. I hope you didn't damage anything and sorry about the novel, just pointing out it's never a good idea to force anything. Even if you think the force your applying isn't much. I wish you the best in finding the problem easy
 
The obstruction occurs with numbers 5 and 8 up. Roll it the other way and same thing, numbers 5 and 8 up. Doesn't appear to be a stuck valve. I used two different magnets to go into those cylinders and didn't find or hear anything bouncing around.

More updates as I go!

Geez, sometimes you feel like you been shot at and missed, $hit at and hit!
 
I assume you bolted a center sump pickup and oil pan on the motor. Might be time to have a look inside.
 
mderoy340 said:
I assume you bolted a center sump pickup and oil pan on the motor. Might be time to have a look inside.
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Yeah, I did that. Since you mention that, I just drained the oil back out. I was going to unbuckle the motor mounts, lift the engine and drop the steering to see if I can get the oil pan off. I'm still looking at it. I'm so far along that it may be easier just to lift the engine out.

If that's not the problem, I'm stumped!
 
68coupe said:
Yeah, I did that. Since you mention that, I just drained the oil back out. I was going to unbuckle the motor mounts, lift the engine and drop the steering to see if I can get the oil pan off. I'm still looking at it. I'm so far along that it may be easier just to lift the engine out.

If that's not the problem, I'm stumped!
Click to expand...

Easier to pull the engine and trans in one whack. Put front tires on the ground and jack up the rear as high as possible and pull both together. Fix your issue, bolt up the trans and drop it back in.... in one whack. Less time on your back and it is easy to fix everything together while both engine and trans are out.
 
Well guys - the engine is out and on the stand. I checked it soon as I got it out to eliminate any problems with the transmission or torque converter. Same interference. Turned it over and pulled the oil pan. Not as much interference. No problem with the oil pickup. Then I noticed the crank journal was real close to the oil pump. I turned the crank but it didn't seem to be hitting. Very little interference now. Took the oil pump out. Still the same. Every time I turn this freakin' thing there's less interference. Then I turned it and the oil pump shaft didn't seem to be turning. I had to use a brass drift to persuade the oil pump/distributor shaft out. I was turning the engine while tapping the gear/shaft out.It came out and looks OK. Maybe it dropped down when I turned the engine over?

Should the gear be that tight coming out? Most Chebbies I have worked on, the gear just falls out.

Still scratching my head! Oh - no interference now!
 
Whaaat?
- Didnt seem to be turning? Is the cam turning?
Yes and no. When everything is fresh, that oil-pump drive can be rotated out with a screwdriver off the cam and plucked out easy.Later as miles accumulate the shaft varnishes up and shaft removal becomes more difficult. Somewhere after 130,000 miles they become really sticky and are sometimes stubborn.
- Sounds to me like the shaft to bushing clearance may be on the tight side or the shaft is bent, or its varnished up.Or ?, IDK. I think it would be prudent to take the pump apart also, but Im not there yet.
-Also should mention that if you flipped the motor upside down, then whatever might have been sitting on top of piston 5/8 may have migrated to a different place with extra clearance and now is no longer interfering. Im kinda stuck on something being in there, or a valve may be hanging up in one of those holes.Depending on your parts combo, there might be between .040 and .180 inch in the quench area. Not much can fit in there and not do damage. I have seen machine screws get in there and be jammed into the piston top and do just what yours is doing. Im not saying yet that the head(s) needs to come off. But it may come to that soon.
-I would pop the covers and check the valve action, and also do a cylinder leakage test in at least those two holes.
-I hope Im wrong.
 
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