1985 K10 6.2- won’t turn over

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kkgp81

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So I noticed this on the marketplace yesterday and I was working on the pool so I scooted over to pick it up. It’s a K10 with 6.2 engine. For what I paid I didn’t even pull the dipstick or even ask if it ran because I bought it for parts (bed, frame for a future project and small bits for my current project). It is a complete truck though. After unloading I figured we would put a batter in it and smoke test it. Turns out no smoke was released and upon kicking the switch another notch the motor turns about 1/8 of a bump or so but won’t really move.

So can I pull the glow plugs to open all the cylinders up and see if it will turn without any compression? I’m assuming the glow plugs are in the combustion chamber so this makes sense to me but figured I would post to see before I get real sporty with the wrench’s.
 

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Rickf

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You will need a 10mm deep socket to pull the plugs. Don't be surprised if one or more loosen but won't come out.
 

Blue Ox

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Right. And if they don't come out, screw them back in before you crank the engine. That compression can launch things.
 

kkgp81

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Right. And if they don't come out, screw them back in before you crank the engine. That compression can launch things.


lol so would that not fix the issue of them not coming out? This is actually my second 85 6.2. I pulled and gave the last one away but figured it might be worth a turn before we bust out the wrenches as short of the wrong color hood/fender it’s a complete original truck that doesn’t look like it was messed with. Going to keep working on my project and may spare this one from the takeoff pile.
 

Blue Ox

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lol so would that not fix the issue of them not coming out? This is actually my second 85 6.2. I pulled and gave the last one away but figured it might be worth a turn before we bust out the wrenches as short of the wrong color hood/fender it’s a complete original truck that doesn’t look like it was messed with. Going to keep working on my project and may spare this one from the takeoff pile.

Well, it might fix it. Just don't stand near it when you do.
 

backwoodsman

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After unloading I figured we would put a batter in it and smoke test it. Turns out no smoke was released and upon kicking the switch another notch the motor turns about 1/8 of a bump or so but won’t really move.

You mean, it only did that once, or it does it every time you try it? Either way, my first thought is, one battery will start a 6.2, but it has to be a really good battery, and that one might not be as good as you think. Put 2 batteries in it that you know are good, and see what happens.
 

kkgp81

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You mean, it only did that once, or it does it every time you try it? Either way, my first thought is, one battery will start a 6.2, but it has to be a really good battery, and that one might not be as good as you think. Put 2 batteries in it that you know are good, and see what happens.

I pulled the glow plugs out and tried. Its locked up or something else odd. The starter pushes but then when you let off it goes back. I cannot turn it with a breaker bar either.

This is with the glow plugs out so there shouldnt be any compression.
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backwoodsman

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So the crankshaft is moving a tiny bit (or the fan wouldn't be moving). Seems like it must be rings stuck to a cylinder wall. Try a 50/50 mix of ATF & acetone, half cup or so per cylinder, and let it soak a day or so. Once you can get it to turn, turn it over by hand for a couple revolutions before you put the glow plugs back in, to get most of the ATF/acetone out so it doesn't hydrolock and break a piston.
 

squaredeal91

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Sounds like a really weak power supply in the video
 

squaredeal91

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I can see it turn in the video slightly. But if the breaker says no than maybe it is just locked up??
 

Blue Ox

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Try loosening the belts too.
 

kkgp81

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So the crankshaft is moving a tiny bit (or the fan wouldn't be moving). Seems like it must be rings stuck to a cylinder wall. Try a 50/50 mix of ATF & acetone, half cup or so per cylinder, and let it soak a day or so. Once you can get it to turn, turn it over by hand for a couple revolutions before you put the glow plugs back in, to get most of the ATF/acetone out so it doesn't hydrolock and break a piston.



I did this since the glow plugs were out. Made a filler setup from a paint gun cleaner bottle and tubing. Got a good bit of the mix in each one. Currently cleaning our pool and need to get back on my blue project so will let it sit a day or two.
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Also- the comment about the power source being weak. It probably is as it’s a single battery that I keep around for stuff like this. The video was fresh off the charger from overnight. If I can get the motor to move I may spend the time for the second battery to get it to really turn over.
 

Ricko1966

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There is a reason I said turn it counter clockwise,and failure to do so may cause bigger problems if it has been sitting a long time.
If enough surface rust accumulated on the cylinder walls as you turn the motor it scrapes off and packs along the top off the piston and gets trapped between the top of the piston and the bottom of the head creating a physical stop. Remember it's diesel, no combustion chamber for all this to pack into. See if it will turn over counter clockwise.
 
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