Stuck spark plug

[bigblockv6]

I've seen a 305 turn and then lock up, the problem was an excessive build up of carbon on one piston. This may be the problem with your engine but then again it's just a possibility and the problem might be something else.

[jagarra]

That is a very good point. I was trying to see the top of the piston with that bore scope. Results were inconclusive. I have the damper off, couple of bolts to go and the timing case will be off. If that is OK, the head on the passenger comes off.

thanks,

gg

[David R Leifheit]

Originally Posted by jagarra

One thing I found curious as I moved the crank in it's travel, I saw very little rocker activity going on.

I have one of those bore scopes, with a camera on the end, which lights up, I am going to poke it into the chambers through the sparkplug holes, see if there is anything interesting in there, I am for sure starting with #4.

My *guess* would be that the timing chain may have broken. You might be able to tell by using your scope down the opening the fuel pump uses (ie. take the pump off...)
Although judging from your postings you will probably already have the cover off before you read this.

If you haven't noticed, there are bolts from the oil pan into the cover, don't forget to look for those and remove so you don't bend the pan.

-<at least I think there are bolts there. Been too long since I tore one apart and have taken apart way too many different engines to keep them straight anymore it seems. I recall 4 bolts, and loosening the pan so that the timing cover comes off easier.>-

[jagarra]

Yes, I figured there were bolts there. Got the cover off and everything looks great, little marking on the gears, the chain is a bit loose, but that may be normal as it drives in one direction.
Started taking the intake manifold off, there are only 8 bolts holding it in correct. That baby won't move at all. I have a bar between the heads and I have another longer bar across that with the edge under the manifold and it isn't going anywhere especially up.

Finally got enough leverage and a lead hammer, it popped off.

[David R Leifheit]

Originally Posted by jagarra

Yes, I figured there were bolts there. Got the cover off and everything looks great, little marking on the gears, the chain is a bit loose, but that may be normal as it drives in one direction.
Started taking the intake manifold off, there are only 8 bolts holding it in correct. That baby won't move at all. I have a bar between the heads and I have another longer bar across that with the edge under the manifold and it isn't going anywhere especially up.

Finally got enough leverage and a lead hammer, it popped off.

The manual shows about 14 bolts.
I would have checked my spare heads rather than a manual but ... well we kind of buried them (on shelves but about a half hour of moving stuff to get to them)

If you have it off then...

Since you have indicated you have the timing cover off... and the engine only rotated so fat (same spot every time) I wonder if you will find a rod cap came off and the piston rod is hanging loose. Until you rotate the crank up against it.

[tommr]

Worst case scenario is something dropped into the cylinder. The dead stop on rotation in each direction can also be the carbon coating sheared from the top of the piston. Doesn't take much to stop the piston. Not uncommon to see on an engine that has been dropped hard. Tape a piece of narrow hose to a vac and suck it out. Ive done it a couple times. Maybe you will get lucky. Good luck.

[jagarra]

IT'S FREE, FREE!!!
Yesterday I went to my local radiator guy to drop off the radiator from the truck. I was telling him about my tail of woe and how the engine was not turning over completely. He suggested I put some the Marvel Mystery Oil in the cylinders and leave it over the weekend. Sort of work it back and forth.
I had some of that stuff as I was adding it to the gas of my Miata. So I stuck about an oz in each cylinder, a double dash on #4.
Later this morning I was playing with it seeing if it would turn over, stopped a couple of times, then all of a sudden I was turning it round and round.
Went a got some more MMO and added a bit more the cylinders, figured I would let it sit for awhile. I have been cranking it over by hand, seems to move a lot easier than it did before.
Monday I plan on laying paper towels over the plug holes and using an impact to crank it over, want to see the color of what comes out.


YAHOO!!

[Andice]

Great news! MMO is a great product. A little added to your gas tank is good for an engine.