worn injector damage?

[matuva]

That's what I bet by looking at that piston : the head of the piston is completely worn. So worn that the piston finally broke.

Is that that kind of damage we meet with worn injectors ?


This # 8 piston on a 929 block (1994?) found in a 1998 rig

Of course, it has to be changed. It seems it can be done "by under", after taking out the oil pan.

Any has already done that ? Do we have to pull the engine or not ?

I will check closer tomorrow, but I do believe it can be done with hte engine inside, but I'm not sure it will be an easy task....
Any idea ?

 

[iamdave0887]

do my eyes deceive me or are those pistons upside down? The swirl chamber should be at the bottom, not the top.

I believe you cannot remove the piston from the bottom. The 6.5 i built in college i couldn't get the piston out the bottom and that was on an engine stand. It's easier to just remove the rob bolts and tap upwards on the rod, driving the piston up and out of it's hole. You'll need a ring compressor to re-install it.

Looks to be that you'll be doing more than just that one if my eyes are not lying to me and the piston next to the one in question is upside down as well.

 

[JiFaire]

You won't get it out the bottom, but you'll need to undo the bottom to push it up and out. If, that is, you can get the pan out of the way to get at the rod bolts. IIRC, you'll need to undo the motor mounts and lift the engine - which is easier on a 2wd. Seriously, it's a lot of farting around, Al. peut-etre it's easier to pull the engine so you can get at everything and check the rest of the stuff out?

It would be a good time to change headgaskets, injectors, glows, oil cooler lines, thermostats, clean rad, ... all the stuff we all end up struggling with while the motor is still in the truck.

Good pic of that divot in the piston, BTW ... sure looks like a pissy injector.

 

[JiFaire]

do my eyes deceive me or are those pistons upside down? The swirl chamber should be at the bottom, not the top.

I believe you cannot remove the piston from the bottom. The 6.5 i built in college i couldn't get the piston out the bottom and that was on an engine stand. It's easier to just remove the rob bolts and tap upwards on the rod, driving the piston up and out of it's hole. You'll need a ring compressor to re-install it.

Looks to be that you'll be doing more than just that one if my eyes are not lying to me and the piston next to the one in question is upside down as well.

I think you're right, Dave... check out this pic ... I think you got a Monday engine there, Matuva!

 

[THEFERMANATOR]

Beings its a 929 block in a 98, I would bet that somebody along the way has been into this thing before. And good eye there DAVE, that piston being upside down would sure cause what happened. I bet the others aren't far behind that one as you can see the one right next to it is upside down too. When you do that the flame that comes out of the pre-cup hits the flat part of the piston instead of the flame dish. The dish is meant to distribute the flame evenly across the combustion chamber and to focus the power, with the piston upside down it would be putting alot of heat where it shouldn't be at normally. And that cylinder is gonna need a SERIOUS honing in probably a CK-10 SUNNEN to clean it up.

 

[3500GMC]

That's erosion from the torch-like flame exiting the pre-cup. You can even see the steel ring land of the top compression ring. Wowser. An injector will be the least of your worries. Seems like somebody's day was turned upside down when assembling an engine... pun intended.

 

[JiFaire]

Like I said, it's a 'Monday' motor...

 

[iamdave0887]

Like I said, it's a 'Monday' motor...

That's pretty tough, even for a monday motor especially if all 8 are upside down. Perhaps a severely hungover monday motor?

 

[matuva]

WOAH! I will go where the truck is and check this !! Good sight Dave!

All pistons on the passenger bank are mounted that way. I do believe we will have to pull driver head to check.

Jim you're right, at this point, better pull the engine to do all of them and hone cylinder 8 at least...


The guy just bought the truck 3 weeks ago. He was happy because the PO told him he completely rebuilt the engine :skep: Too much beer during the rebuilt I bet...

Now, I will have to calm the owner. Before we opened the engine, he was telling me he has to go and "talk" the PO.... now that we see what we see, I doubt he will just talk :rolleyes5:

I understand now why Garfield says he hates mondays...

 

[matuva]

more pics from this monday engine :

panoramic view of the upside down bank of piston



is that a crack ?



not worse than in #8 but ...



I think it should be a nice idea to check driver side bank too

The owner is on vacation at the moment. We decide we must let him having good time for now, and didn't call him.

We'll wait till he comes back and see what he decides...

 

[buddy]

Wow, that sucks, I saw the first post and it looked wrong. Nice piece of work, thanks for sharing

 

[JiFaire]

Yep. That there is a candidate for replacement. Good pics, Al.

 

[bison]

Yep,i side with the others,shade tree mechanic full of booze at work.
Looks like honing wont do any good on #8 and 4. Too far gone.

 

[WarWagon]

I think you're right, Dave... check out this pic ... I think you got a Monday engine there, Matuva!

See I am not totally worthless! I can always serve as a bad example. :hihi:

The scuffing is what happens when things get too hot and the oil fails and/or you run out of clearance. Pistons being upside down I imagine would heat em up. For grins you could see if the extra clearance for #7 and #8 is in another hole...

The 'cracks' look like erosion? Any warranty express or implied from the PO's rebuild?

Now the $24 question: was it consistently wrong on both sides? I mean don't you have to turn the American manuals upside down to assemble things properly down under, eh? :rof:

 

[matuva]

The guy finally follows our suggestion and decide to buy a "used but good engine".

"Luckely" for him, another guy totalled a truck a month ago, and so we found an available used engine...

we will check this one, which will probably go in another truck after we finished : other than the broken piston and upside down other ones, it was running fine.
I suspect a crack in # 6, though there was no water in oil or oil in water, no mayonnaise, no hydro lock, so ...