Bought an LLY Cranks no start

[PureHybrid]

Pull the upper valve cover, check rocker movement and bar it over to one of the valve set marks and see if the rockers are close to where they need to be.

I still think something is bound up. If it truly has zero compression it should buzz over real quick on the starter

 

[03LB704.5LLY]

Pull the upper valve cover, check rocker movement and bar it over to one of the valve set marks and see if the rockers are close to where they need to be.

I still think something is bound up. If it truly has zero compression it should buzz over real quick on the starter

I guess I will pull the valve cover tomorrow, I see the pin is still there

 

[03LB704.5LLY]

Do any of you guys think it is possible that the cam has just worn to the point that every valve is off?

 

[2004LB7]

No. But as PureHybrid said. It would be a good idea to pull the covers. You should be able to inspect the cams and rockers, etc. You would easily be able to tell it the cam was worn that bad when you remove the cover.

 

[1FastBrick]

So what does it mean if you get 0 compression? I have checked all and the gauge reads zero, but I do feel air coming out of each one. I put my finger over the glow plug hole and get a push and a pull... I have no idea what the issue is, any advice?

A friend of mine bought a harbor freight tester and had 0 compression as well. We found out the adapter was compromised and not allowing the gauge to read any PSI. We had to go back and exchange it.

If there is enough air coming out that you can not keep your finger on it, it should register on the gauge. If you find that to be the case, Either rent one from an auto parts store or get another one to be sure.

 

[03LB704.5LLY]

No. But as PureHybrid said. It would be a good idea to pull the covers. You should be able to inspect the cams and rockers, etc. You would easily be able to tell it the cam was worn that bad when you remove the cover.

Thanks guys! That will be the next step.i will update again tomorrow after I have done that, I really appreciate everyone’s suggestions and knowledge.

 

[03LB704.5LLY]

I did check the tester with the adapter on it with the rubber tip blow nozzle on my compressor and it did read to 80psi. That was my first thought as well when the gauge did not move while turning over... I can keep my finger on the GP hole while turning over but it pushes slightly and then sucks pressure I’m guessing that’s a valve/cam issue and that’s why I jumped on the shear pin idea.

 

[2004LB7]

I think renting a compression tester is a good idea too. You can at least test it against your own and see if it is the same

 

[03LB704.5LLY]

I think renting a compression tester is a good idea too. You can at least test it against your own and see if it is the same

That’s not a bad idea, I checked with advance locally and they did not have one but I will check around some more.

 

[TheBac]

Got a Harbor Freight nearby? Their comp tester has the Dmax glow plug adapter and works fine.

 

[03LB704.5LLY]

Got a Harbor Freight nearby? Their comp tester has the Dmax glow plug adapter and works fine.

That’s where I got my tester but it did not have a duramax adapter, just 6.5. It was also around $140 I had read about one around $40 that Had the adapter but it was out of stock. I’m going to check another HF nearby and see if the other one is in stock. I had to order the adapter and I’m game for trying one that is known to work!