3B Death Rattle (2 Viewers)

[RufusTheDufus]

He's most likely assuming the freeze plugs are the tops of the pre-combustion chambers. You can't inspect them without pulling the head.

Nothing should have bent that glow plug. Hate to be the bearer of bad news, but something let loose in that cylinder bore and it's no longer firing. You likely have a cracked/dropped pre-combustion chamber.

 

[seatosummit]

...forgive my ignorance, but how did you get a view of the pre-cups?

So I though that I had a visual on them, based on this illustration in the service manual:

(fourth image down, showing removal of combustion chambers)

Seems now that the illustration is a bottom view of the head, post removal. So in that case I don't know what exactly I was looking at near the valve rocker assembly.

 

[seatosummit]

He's most likely assuming the freeze plugs are the tops of the pre-combustion chambers. You can't inspect them without pulling the head.

Thanks, Rufus. I was under the impression that the freeze plugs were situated on the side of the block (by where block heater plugs in).

Nothing should have bent that glow plug. Hate to be the bearer of bad news, but something let loose in that cylinder bore and it's no longer firing. You likely have a cracked/dropped pre-combustion chamber.

Not the bearer of bad news. I have suspected this all along, just trying to confirm now more than anything. It's like post catastrophe investigation.

So let's say its a dropped/cracked pre-cup. What happens next? Can I potentially repair just one cylinder and limp along, or should I start parting out and saving for a new engine?

Austin

 

[alberta mac]

with the edic arm off the truck it should run, you will have to move the edic manually to shut the motor off.
The purpose of the edic system is to shut the vehicle off if you run out of oil.
If you are out a pound or two when you torc down the injectors your milage will suck.
check the manual on torc specs. it could be 33ft lbs, but don't quote me.
Not draining your water separator will result in distorted injectors eventually and thus poor milage.

 

[seatosummit]

with the edic arm off the truck it should run, you will have to move the edic manually to shut the motor off.
The purpose of the edic system is to shut the vehicle off if you run out of oil.
If you are out a pound or two when you torc down the injectors your milage will suck.
check the manual on torc specs. it could be 33ft lbs, but don't quote me.
Not draining your water separator will result in distorted injectors eventually and thus poor milage.

I no longer have an EDIC, rather have installed a manual cable. So I can certainly position it such that it wont start.

Noted on the torc specs, and water separator, thanks.

 

[amaurer]

So let's say its a dropped/cracked pre-cup. What happens next? Can I potentially repair just one cylinder and limp along, or should I start parting out and saving for a new engine?

Absolutely... but since you're in there it makes a lot of sense to do em all. The bulk of the expense is accessing the items in question, doing 4 will not be 4x the price by any means.

 

[cruisedeisel]

You can check precups by sticking a straw down the glow plug hole. if the straw bottoms out in the same spot everytime, your precups are still there. drop the oil pan beacuse i had a nasty shake and lack of power when i snapped my crank shaft at the #2 bearing.

Let me know if you need a crank shaft and stop running that engine.

 

[cruisedeisel]

P.S. does you harmonic balancer look wobbly?

 

[seatosummit]

OK-

So straw test has confirmed dropped pre-cup;

Cylinder 1,2,4 all allow screw driver to drop about 4 inches. Cylinder 3 goes all the way down, with no resistance.

 

[amaurer]

OK-

So straw test has confirmed dropped pre-cup;

Cylinder 1,2,4 all allow screw driver to drop about 4 inches. Cylinder 3 goes all the way down, with no resistance.

So then the big question is if the cup lunched the head or not... if the entire cup is missing like it sounds, chances are pretty good the head is chewed up too. Gonna have to pop it off to check.

 

[RufusTheDufus]

A few of the visible head freeze plugs circled in red.

Pull the head and post photos. If the dropped pre-cup didn't screw up the cylinder walls you may be able to get away with replacing the piston in that one cylinder. I'd use a dial bore gauge to check the cylinder walls on the three "good" cylinders. If they aren't barrel shaped and within spec you can consider replacing the piston in the one bad cylinder.

If the head and/or the cylinder walls are damaged the economics of a complete rebuild likely will make more sense than a fix of this specific problem.

 

[FF LC FREAK]

Yep. Pull the head and see what kind of damage has been done. Take pics. The head may be salvageable, but it will need to be diagnosed by a good machine shop. You asked before if you can do just one cylinder. Yes, you can. You most likely will need to get a new piston, liner and some head work. However, as mentioned above, if you are doing that much, you might as well do all 4 cylinders.

That sucks. Sorry to hear this.

 

[RufusTheDufus]

The color of the top of the valve in the bad cylinder makes me think that the head is munched too. Why would this one valve be cleaner than the others?

 

[amaurer]

The color of the top of the valve in the bad cylinder makes me think that the head is munched too. Why would this one valve be cleaner than the others?
View attachment 889227

That valve looks overheated to me - if the seat is destroyed and the valve is staying open the valve will overheat when it can't be cooled by contact with the seat. It tends to heat them up and boil the oil off of them making them discolored and "clean" looking.

Its a bit weird that that one is an intake valve tho.

 

[roscoFJ73]

how should I go about that?

Thanks, guys for all the support.

Austin

If things are getting chomped up ,you really need to pull the head off and have a look at the total damage. There could also be metal fragment scraping on the bore and its the only way to retrieve them.
If its a high miler,be prepared to spend $$$

 

[cruisernerd]

Any news yet?

 

[seatosummit]

Hey Guys-

Sorry for the long delay in response--last minute trip to Asia for work that left me out of contact with the digital world.

No real news yet, as I have not yet pulled the head.

I bought an old merc as a daily driver, so the pressure is somewhat off to make something happen for the truck immediately. Although I do want to make sure that she gets going as soon as possible.

I have had some time to think about my options:

1) I can either try and patch together the existing, tired 3B with single cylinder rebuild, and drive for as long as it'll let me.
2) Do a complete rebuild, in which I take care of all of the cylinders while I have it apart.
3) Swap in a new power plant. I want t 13BT with H55F.

Most realistically, I want to patch it up (option 1) and save some cash to afford option 3 a year or two down the line. I know this assumes that there isn't major damage to the top end from grinding pre-cup shrapnel on cylinder bore, etc. An update on this soon...

Interested in everybody's opinion on this approach.

Also, recommendations on a source for single cylinder rebuild kit would be killer.

Thanks,

Austin

 

[seatosummit]

So I pulled the head...

Precup on cylinder 3 fractured in half, and dislodged into the cylinder. The cracked portion shattered, cracked both valves, and melted and fused to the piston.

The head and cylinder both appear to be OK. Although I am interested in your interpretation of the photos.

Bottom end sounded fine as we pushed the rig in gear with head pulled.

Image 1: Top down view of cylinders 2,3,4. Note that the metal flakes in the other cylinders were not there when head was pulled, but rather fell in after head gasket was pulled.

Image 2: View of the bottom of the head.

Image 3: What became of the remainder of the precup while trying to pull it out.

Image 4: View of cylinder 1. You can still see the factory bore, which as I understand is a good sign for the health of the rest of the engine.

Image 5: Closer view of the problem cylinder.

Image 6: Head gasket. Notice the punched out section that lines up with where the precup dropped.

 

[bj40green]

Your images don't load.

Rudi

 

[seatosummit]

They should now.