"Poof" and now you are stuck

[TanTinCan]

Issue: My 4.2 is currently not running. I was driving down the road and heard a "Poof" sound. I know, I know, great description. I pulled over and the motor was running hot and a little bit of oil smoke was coming out of the oil breather filter on the top. The motor turns over and I will give you the actions that I took below.
Actions I took:
Oil: I drained the oil and there was no metal or off odor to it.
Coolant: Drained; a little rusty color to it and no oil or film on the top. I let it rest for a day in a bucket to make sure. So that was normal.
Piston Compression: Tested; no compression in 1-3 with some compression in the following cylinders. Around 30-100 psi ish
Note: I put some oil through the spark plug hole, in cylinder 1 and tested the compression again. No luck = no pressure.
So... my thought is that the issue could be something to do with timing maybe. Could the timing belt be off? I'm still learning

I also don't want to take the hole thing apart.

 

[ag4ever]

Pull the valve cover and see what the rockers and valves look like.

 

[TanTinCan]

Pull the valve cover and see what the rockers and valves look like.

They are not moving when I crank the motor

 

[AJ2393]

Does that mean you don't see the the pushrods moving either?

 

[TanTinCan]

Does that mean you don't see the the pushrods moving either

Does that mean you don't see the the pushrods moving either?

the pushrods don't move

 

[sdsupilot]

With the valve cover off none of the pushrods/rockers are moving while the engine is cranking? If that's the case I would next look at pulling the timing cover off the front of the engine. If that is all good it could be a broken crank but I've personally never heard of a broken crank in a 258.

 

[AJ2393]

With the valve cover off none of the pushrods/rockers are moving while the engine is cranking? If that's the case I would next look at pulling the timing cover off the front of the engine. If that is all good it could be a broken crank but I've personally never heard of a broken crank in a 258.

x2. That would be my next step. Inspect timing chain and gear. Something mechanically is impeding the movement of the pushrods/etc. Does it sound like broken bolts tossed in a wash machine when you try and crank it? I feel something potentially this major would leave more clues.

 

[93_Fummins]

Timing setup is likely compromised. Broken chain, or broken gear, or backed off gear.

 

[Belizeit]

Hopefully not composite gears. Those are trash.

 

[ag4ever]

Hopefully it is just a broken timing chain.

 

[jpnmaine]

Push rods straight?

 

[Kim Dawson]

Poof should be a whole lot better than bang!

 

[TanTinCan]

Update with some pics!

 

[TanTinCan]

 

[TanTinCan]

 

[TanTinCan]

Okay so... bad news, the timing chain cover was cracked. It came off in pieces and the chain boke. Taking with it some gear teeth. I removed the broken chain and loosen the valves. I was able to move the crank by hand and all the valves moves. I also removed the rods, which were straight. Next will be to take the head off to inspect the pistons and walls. I will also pull the crank for anything out of the ordinary.

 

[gr8dain]

That sucks. But you are sticking with the 258?

 

[Chamba]

Something similar to this has led me start the Cummins R2.8 conversion in mine.

 

[TanTinCan]

 

[TanTinCan]

Pulled the head off and lifters. All is in prefect condition. The oil is from a compression test. I am going to replaced the timing chain and gaskets. whats the best timing chain and gears?