mopar_runner

Damage from where the head gasket blew out..... or previous damage which caused the head gasket to blow out. Waiting for the heads to be checked out from the machine shop. Head condition will dertermine the fate of the 3.0

snap-on

number 6 right?

not unheard of if you just keep dumping coolant in it every day and run it like that for months.... the water/steam eats away at the piston/cylinder wall.

MudHippy

Looks just like my #1 piston...after chewing on the head gasket fire ring. I don't happen to have a pic of the piston(though I could take one, since the whole set of old pistons is still sitting in my shed). But I do have a pic showing the culprit.

Redeth005

Wow dude i soooooo feel your pain. My truck had so much crap that went wrong with it when i bought it. I easily dropped $1800 in parts and machine shop alone when i chose to rebuild it. My mechanic pulled out loads of water and antifreeze from the engine block and its cylinders. think he said it was a full bucket worth of liquid. My cylinders had to be honed, crank needed a new size, and i had to replace one piston because it was just in so bad of shape.
I wish you the best of luck dude. Really i do. lol

scope103

What DOES the cylinder wall look like? The damage to the piston looks (to my untrained eye) like pre-detontation (knocking).

I'm pretty sure that piston has to be replaced, but before I even removed it I'd look at the cylinder wall. And again after I removed the piston but before getting a new one.

Let us know!

MudHippy

Well...maybe not "just like" my #1 piston(yours looks a bit worse actually). So how about very similar?

It's been dinged up a bit more since then too. But still shows the gist of it though.

TNRabbit

These engines will run with ALL KINDS of damage for thousands of miles. It will PROBABLY be fine like that, provided the cylinder walls & rings are ok.

MudHippy

I tend to agree. Because...

I ran those damaged pistons(after the replacing the head gasket) without issues for another ~6000 miles. And #1 wasn't even the one that was REALLY messed up.

Which was #3.


Anyhow, they worked just fine up until #6 cracked. Then I finally went ahead and replaced all of the pistons(and pins).

mopar_runner

nope... #1

That is the exact spot mine blew out!

I just purchased this knowing it had a bad head gasket. It looks to me like this was actually previous damage and the main reason the gasket let go. The reason i say that is because it looks like that area of the piston has been filed/sanded. Look close at the shiny areas of the first close-up.

mopar_runner

Cylinder wall actually looks good. I got a screamin' deal on this so i dont feel bad about dropping some coin on repairs. I was just going to replace HG and do a full tune-up (oem wires, cap, rotor, etc), but now it looks like im freshening up the bottom too. Bores look good and measure out well within standard spec. Because of the hotspot on #1, looks like its getting new pistons, rings, bearings and a hone job. I just got the heads back from the machine shop. They checked out good.... vac tested @ 17 in hg, .002 warp. So, Had them resurfaced just to make sure.

mopar_runner

I would think that #3 would detonate like crazy with all those pockets. Thats why im replacing mine. The goal is to get about two to three years of daily driver/weekend wheeling out of it..... then it goes under the hot knife for trail rig transformation

MudHippy

It sorta surprised me that it ran fine like that too...trust me. Of course the fact that it did was also the main reason I decided to leave #1 alone...for the mean time.

mopar_runner

I know im going to be using an OEM full gasket set, ignition wires, cap and rotor. Any suggestions on brand or source (other than OEM) of piston/ring set?

JCilmi5

Did my head gasket and found #6 piston damaged as well. Bad news is the machine shop sold me a RH bank piston, when I needed a LH bank piston. REAL bad news is I didn't realize they were shaped differently until I put it all back together and had a piston slap. Did anyone know the pistons with "L" and pistons with "R" have a different shape? Anyway...its always easier the second time around.

MudHippy

You're kidding me...

Uhh...yeah. Hence the "L" and "R" to deteremine which bank they go in + the dimple/cavity/indentation that serves as the front mark(which when correctly installed should be towards the front of the engine block). Meaning, they gave you 2 chances to get that right(no pun intended)...and you STILL screwed it up!

Not too mention pistons #2 & #4 staring you in the face the whole time. "One of these things is not like the others..."

BTW, I don't know what I'm supposed to be seeing in that pic. But it looks like your block surface is pretty well toasted(badly pitted/eroded/corroded). Unless you had that thing decked, your wasting your time.

Also looks like somebody tried using some kind of coolant system stop leak. Which, if anything, probably only exaserbated the issue. Leading to more extensive damage due to continued use of the engine while in that major a state of disrepair. IOW, somebody should have parked it until it got fixed right. Instead of trying to fix the HG with some kind of magic potion, then keep on driving it. Which...obviously...didn't work too well for an idea. Did it?

JCilmi5

Yeah I know mud hippy. I made a big mistake by using a "R" piston when it should'VE been an "L". Now I'm paying for it. Believe me, I'm beating myself up over the mistake I've made.
Also the FSM says the pistons have either a 1, 2, or 3 mark on the top of the piston to specify which standard diameter I have. Except for the toyota dealership, everyone else has only one standard size piston. My piston has mark 3, while the mark on the block was a mark 1. I'm asking because the stealership is way more $$ and the machine shop I'm dealing with will replace my "R" piston with an "L" piston for the cost of labor to press the wrist pin out and back on the correct "L" piston. Since they made the mistake of selling me the wrong piston to begin with. I just really don't want to put another wrong piston in there.
I'll be sure to inspect the oil clearance between the new piston and the cylinder wall. As well as inspect the cylinder wall for damage from the wrong piston banging around in there for the last 500 miles. BTW, it only makes noise when the engine is warming up. Not at normal operating temp. How different could the shape of these "L" and "R" pistons really be? Plenty different I guess.
No I did not have the block decked since its still in the truck. And I think that photo was taken before I scrapped/cleaned the gasket surface. You really think I'm wasting my time by putting it back together with out resurfacing the block? I considered pulling the engine to have the machine shop do a rebuild. But it seemed really exspensive. And the truck ran good before the head gasket went out at 242k. It ran good the last 500 miles after the HG job too. As for the stop leak, that was from a long time ago in hopes of fixing an old leaky radiator that I have since replaced and flushed the cooling system out and replaced the coolant with new. MY intention with the stop leak had nothing to do with the head gasket. Any other considerations/ recommendations would be greatly appreciated. Believe me, this job has given me the opportunity to learn A LOT! So I'm totally into your feed back. So I can learn even more. Thanks