GM 262 V6 Diesel - 80s

[Drew]

So I bought a Generac 100 amp generator last year with the intent to fix it.

I finally got time to start working on it and got it somewhat freed up so I can get it to turn over....sort of.

I took the injectors out and put some penetrating oil in there a month or so ago.

The unit has 153 hours running at 1800 RPM.

Here are the symptoms.

It will turn over about 2/3 of a rotation and the locks up hard. I have to use a pipe wrench to get it unstuck and can counter rotate it about 2/3 of a rotation and it locks up hard.

I then use the starter to get it to go forward.

If I put say a long straw down each piston where the injector would be, and if one of them didnt move, would that indicate a bottom end problem with a rod?

I am working on a video of what it does now.

 

[NVW]

Could also be a dropped valve

 

[Drew]

http://www.youtube.com/watch?v=hcYup1Ql9Mo

 

[Drew]

How can I tell if it is a dropped valve?

I have the valve covers off.

 

[NVW]

You can see if they are still in their retainers, it doesn't sound like it though. I would remove the injectors or glow plugs it it has them and try turning it then. the straw in the injector hole would tell you if the pistons are moving.

 

[btfarm]

If you could get it to turn 360* you would be able to see all the valves in action but since that isn't happening, I guess you might have to pull the heads.
But first:
Is the starter pinion disconnecting from the flywheel?
Is there a bolt or something rattling around the flywheel area?
Nothing wrong with trying the straw trick either.
I'm thinking you meant more than 100 amps.

 

[Drew]

Now I an get it probably 3/4 of the way over.

On the right side, I took all the valve rockers off and found one intake valve that wasnt always coming back out when I pushed on them. All of them are in their retainers from what I can tell.

Yes, I already have the injectors out.

I went to try the "Straw" trick, but my straws are too big, so I'll find something smaller tomorrow.

No bolts in the flywheel area. I already took the covers off.

Yes, the starter disengages. I had taken it off earlier to make sure it was working fine, and it does.

Any chance the injector pump is "locking up"?

 

[Drew]

I want to avoid if at all possible, from having to demate the engine from the generator...according to the book, that is a PITA!

 

[3500GMC]

A piece of glowplug between the piston and head maybe...

 

[Drew]

Well, I did take the glowplug out of just that one, and it appeared to be whole.

I'll check the others tomorrow, good thought.

 

[NVW]

This is just a thought but if it was seized before you freed it there could be ridge of rust in one or more cylinders.

 

[Drew]

It was a former military generator. Based on the condition of the oil and other aspects of the engine, we believe the unit ran fine.

There are some control parts missing from the control panel, we believe either it suffered a generator electrical component failure, or the system was just used for parts.

At least....that is what I am hoping, and I can fix that a little easier than an engine rebuild.

 

[GenBiltstein]

Get you one of those snap on remote cameras and have a look see through the injector holes. Best investment I ever did. That camera has saved me time and money from everything from under the dash to rotating motors.
Peering into cylinders to check for TDC is a breeze.
You can drop the small camera right in and look at the screen.

Drop the oil pan and look at the connecting rods.

 

[WarWagon]

I tore one of these engines down in college for an engines class. The fuel in the IP was yellow varnish. Of interest: aluminum heads on that engine.

Have you eliminated the generator section from being the problem? Bad gen set bearing or thrown winding?

I do not hear a thud of a foreign object in the engine.

I would pull the IP and if it is still tight then the heads. Oil pan last. Then you need to separate the generator... At least the heads are easy to get to.

Oh and stop jamming the starter like that - you are arching pits in the brushes and all when it stops like that!

 

[6.2 turbo]

On the olds v8 the injector pump pulls right out the drive is just flat,no bolts like the 6.5, I doubt that its your problem though,as the pump drives snap pretty easy.