673 Engine Won't Turn... Any Ideas ?

[steve s.]

Hello, I have been learning a lot following the discussions here, and now I have a problem I hope someone can help me with. I have a 1961 B 613SX that I bought over the winter. The truck had not run in many years but after a lot of tinkering, I finally got it to run and backed it into a corner of the garage where it sat out the winter. It seemed to run pretty good and I had no doubts about the engine being okay. One evening last week I decided to start the truck. I used a little ether and it fired up quickly and stalled, as I had forgotten to push in the fuel stop. It did run long enough that the oil pressure guage was moving up past 20 psi or so. After another small shot of ether it fired right up again, ran smooth for maybe a minute or less, and stalled. when I tried the starter again, the engine would not turn. I left it alone until the following night hoping it was locked up on ether or the starter drive was stuck or something else simple. No such luck. I took the starter out and it is ok. I can easily turn the engine over with a small bar on the flywheel, but it only goes about a quarter turn and then stops again. It turns back and forth in that 1/4 span fine but that is it. I don't hear anything at all when trying to turn it. I pulled the bottom off the air compressor just to check it and it appears ok. I am stumped. I would think a spun bearing would not turn at all, and a broken connecting rod would surely make some noise. Does anyone have any ideas about this ? I expect I'll have to pull the pan , but is there a reason I should look in another direction ? Thanks, Steve in PA

[Rob]

Hello, I have been learning a lot following the discussions here, and now I have a problem I hope someone can help me with. I have a 1961 B 613SX that I bought over the winter. The truck had not run in many years but after a lot of tinkering, I finally got it to run and backed it into a corner of the garage where it sat out the winter. It seemed to run pretty good and I had no doubts about the engine being okay. One evening last week I decided to start the truck. I used a little ether and it fired up quickly and stalled, as I had forgotten to push in the fuel stop. It did run long enough that the oil pressure guage was moving up past 20 psi or so. After another small shot of ether it fired right up again, ran smooth for maybe a minute or less, and stalled. when I tried the starter again, the engine would not turn. I left it alone until the following night hoping it was locked up on ether or the starter drive was stuck or something else simple. No such luck. I took the starter out and it is ok. I can easily turn the engine over with a small bar on the flywheel, but it only goes about a quarter turn and then stops again. It turns back and forth in that 1/4 span fine but that is it. I don't hear anything at all when trying to turn it. I pulled the bottom off the air compressor just to check it and it appears ok. I am stumped. I would think a spun bearing would not turn at all, and a broken connecting rod would surely make some noise. Does anyone have any ideas about this ? I expect I'll have to pull the pan , but is there a reason I should look in another direction ? Thanks, Steve in PA

It sounds more like bad connections from the batteries, or the series/parallel switch is giving problems. There are three different types of switches used and parts are no longer available for any of them, but the switch can be purchased complete. I am assuming the truck is still a 12volt system with 24VDC starting. You have to ensure all connections are clean and tight, with good batteries in the system or you'll have a reall fight on your hands to get it to crank.

Rob

[theakerstwo]

If i understand right it will only turn a1/4 turn with a bar. If that is right then it is not good so start to pull injectors and see if it will turn with a bar and watch for coolant coming out of the head. If you free it up like that the a head has to come off to check out more . If that dont help then look for a dead cat in the belts and if non then pull the drain plug and check for metal . Or pull pan and have some one hold a lot of pressure on the bar trying to turn crank and then you take a long sreww driver and try to slide each rod side ways. That will tell you which rod is locking the engine if any and if you find it locking the engine then pull that rod brg and check and if ok then look for a bent rod. Those are thin rods and i have seen people bend them but never to lock a engine. if it is a main brg then you will see it as you look up arond the main cap. If it is a rod it should have a rod cap blue. When youy drain the oil watch for the first little bit that drains and see if there is any antifreeze in it.

[HeyCharger]

I can easily turn the engine over with a small bar on the flywheel, but it only goes about a quarter turn and then stops again. It turns back and forth in that 1/4 span fine but that is it. I don't hear anything at all when trying to turn it.

Hi Steve. I'm not a mechanic so this may be wrong.

When you turn it with the "small bar" you say it goes a quarter of a turn and stops. Is this a sharp, abrupt stop, or could it be just on a compression stroke. Just remember, the compression (I presume it's a diesel) is over 500psi. A normal car is around 80psi. When I've turned mine over, I've needed a BIG bar with plenty of leverage.

First thing I would do is take out a few (or all) injectors and then see if it turns easily, with no compression.

As has been said, you need a lot of ooommmppphhh to turn these over. Good batteries, or a good air supply are a must.

Hope this is helpful. Rod.

[ThaddeusW]

Hi Steve. I'm not a mechanic so this may be wrong.

When you turn it with the "small bar" you say it goes a quarter of a turn and stops. Is this a sharp, abrupt stop, or could it be just on a compression stroke. Just remember, the compression (I presume it's a diesel) is over 500psi. A normal car is around 80psi. When I've turned mine over, I've needed a BIG bar with plenty of leverage.

First thing I would do is take out a few (or all) injectors and then see if it turns easily, with no compression.

As has been said, you need a lot of ooommmppphhh to turn these over. Good batteries, or a good air supply are a must.

Hope this is helpful. Rod.

I agree with Rod, you might be hitting compression. Does it feel spongy or does it come to an instant dead stop? Loosten your injectors with a set of die pry bars and see if you can turn it freely.

[vanscottbuilders]

A DEAD CAT ????

THAT'S GOT ME LAUGHING GLENN.

Anyway - Glenn's right, if you're not up on a compression stroke,

you need to find the obstruction before you go any farther.

The injectors are the easiest place to start. And the fix is the easiest to do.

Then it gets more difficult from there.

Good Luck,

Paul Van Scott

[steve s.]

Thanks everyone. the problem is not the starter, it tried like heck to turn the engine , and yes I have already gone through the series/paralell switch and battery cables to get it running initially. My batteries are good and the 24 volt starter really gave it a good spin. Yes the bar is small that I'm using to turn that 1/4 turn but I'm quite sure that I'm up against more than compression.

I did not even think about it being locked up with anti freeze, or to take out the injectors. That is just the kind of lead I was hoping someone would offer. I will get to work on it as soon as I can and let you know what I find.

Thanks again, Steve

[theakerstwo]

A DEAD CAT ????

THAT'S GOT ME LAUGHING GLENN.

Anyway - Glenn's right, if you're not up on a compression stroke,

you need to find the obstruction before you go any farther.

The injectors are the easiest place to start. And the fix is the easiest to do.

Then it gets more difficult from there.

Good Luck,

Paul Van Scott

Yes i have seen that happen to a 1693 one time it throwed all of the belts off of it and the driver saw that it was not charging so he called me .I said it may have locked the alternator with a bad brg so he said will have it towed in to the shop and one of the guys came up and said come look at this. There was a big cat cut into and i guess when the truck was sitting over night the cat got up there and got in the belts and throwed them but this was a big cat i mean one that could make a dog go up a tree and that has been 25 years ago but i remember the dead cat.