Opened up my 2JZ today, Veeky Forums, found pic related

Opened up my 2JZ today, Veeky Forums, found pic related

Scoring or carbon tracking between some rings? Nothing I can physically catch with a fingernail

...

You don't have a 2j

Why wouldn't I?

Pulled it out of pic related

No actual engine mechanics kicking around Veeky Forums? I'm not experienced enough with worn cylinders / lining to be confident in my ability to judge problems properly

Piston rings have a gap in them that closes when the engine gets to operating temp. Before it closes completely, an inconsequential amount of oil and stuff could get through. I assume that streak is where the gap is located.

I am familiar with piston rings, and I also think that's what it is, just wanted some other opinions in case it's something someone has dealt with before and isn't carbon tracking from worn / improperly gapped rings

Strangely it's only present on cylinders #3 and #5

Someone hand dingleballed it, whatever the story is doesn't end there, time to get an LS1

saw a corvette or viper and shat itself a little

it could be that carbon fouling or something else has caused the piston rings to actually seize to the piston. normally they should be able to rotate.
Unless you want to rebore the cylinders, freeing the rings at this point may impact compression.

>Tripfags coming into genuine automotive thread and being faggots incessantly

holy shit who saw that coming

Trying to keep all the work I'm currently doing to the engine strictly on the top end. You think removing the pistons and rotating / freeing the rings could impact compression? How so?

>user being a little bitch as usual

holy shit who saw that coming

>user doesn't know what a dingleball hone is and doesn't understand it's connotation

holy shit who saw that coming

tripshit is correct

>Trying to keep all the work I'm currently doing to the engine strictly on the top end.

as someone that's been there, I can guarantee that after you throw everything back together you'll wish you did the bottom end.

just rebuild it the whole thing. do it nice, or do it twice.

You're probably right, however the stock 2J bottom end handles high horsepower solidly, and I have no issue pulling the engine again and doing the bottom end later when my budget allows for better internals

>newfag doesn't know what heartbreaker does for a living
Epic

>he doesn't know our residential tripfags or their lifestory, newfag

this place is cancerous

>the stock 2J bottom end
You don't have a stock bottom end, it's been apart before, there was a problem with it, and it was "fixed" by a shitty shop or in someones garage. It needs machine work, you're probably better off finding another short block because whatever the original issue was is going to be disguised by the shitty work already done.

I was planning on removing the oilpan and checking things out anyways, and shitty quality work would be in line with the rest of what I've found in the car.

Having said that it displays all the symptoms for carbon tracking. I'll see how the bottom end lookover goes

>2j
>Expensive


Also what the fuck is wrong with the water passages

This

looks like cavitation

>implying anyone gives a fuck

>piston rings and oil issues

If your piston rings are done properly this isn't the case. It doesn't look like a piston ring failure. It looks more like your cyls are starting to catch up with age. I would have them replaced


I also dont like the look of those pistons. If you have a forced induction 2JZ i would suggest planning for a replacement

>Cavitation inside the cooling passages

Holy fuck is it really a common thing???

Yes.

t. big city mechanic

Just googled it
>cavitation bubbles are essentially a result of low temperature boiling induced by low pressure. Cavitation may occur as liquid moves swiftly around constrictions and through orifices, particularly when such orifices change shape from small to large, as in water moving past a gate valve, or worse, through a partially opened valve. These conditions create a Venturi effect and the rapid change in pressure is conducive to the formation of cavitation bubbles.
>A form of cavitation erosion occurs inside cooling systems when impellers or circulation pumps turn more quickly than the fluid can readily move. The speed of the impeller “tears” the fluid, creating a void or bubble.

Sounds to me like an engine's cooling ducts are the perfect environment for it to occur.

rings need to be free to properly swipe the cylinder walls and keep the cylinder sealed on the bottom end. stuck rings contribute to excessive wear, blow-by, scoring, etc. eventually they will break and then you'll really be screwed

It is indeed a GTE engine. It's from a '94 with 95xxx KMs. What about the pistons puts you off?

If that's your cyl walls with a turbo engine you might wanna look into fixing that shit ASAP before you put it back together.

I just see the piston kinda eroded. That and the cyl walls make me think that the engine is due to a rebuild.

Primarily due to the glazing or what specifically?

Just constant usage.

No matter how much upkeep you do to your engine, metal just erodes away with constant use. Its just how engines work.

Just because your engine needs a rebuild it doesn't mean you fucked up, sometimes you just kept it running hard for a long time and it needs a pick-me-up.

Oh I understand the necessity of needing a rebuild, constant combustion on any surface will erode it over time, it's just got such low KMs for its age and I'm just getting conflicting opinions from engine specialist co-workers / people in this thread.

I haven't had enough time to drive it to fuck it up, guy in Japan did that for me. If you saw some of the hackjob body work on this thing... Buying sight unseen and importing is a fickle thing.

>It's from a '94 with 95xxx KMs.
Yeah. A quarter mile at a time.

I can promise you this car wasn't a drag car.

Engine and the entire cooling / fuel / etc. systems are all stock. It's just riced to fuck

I am not the best mechanic in the world and i am not there to verify. Trust the mechanic that can check up the engine closer and that is not trying to scam you. I probably say what i say because i am autistic about having everything in perfect state, specially a sports car. Is it the ENGINE with low KM or the chassis?

>Engine and the entire cooling / fuel / etc. systems are all stock
>engine stock

Good

>cooling stock

That's not always a good sign.

Chassis and engine have matching numbers, so I presume both.

I agree, however it was running stock boost and everything, and those engines are detuned like mad from factory. Just a SARD boost gauge is all that was added.

>detuned
>low miles

Then it might just be me. But something's off. Are you sure that the jap guy wasn't going batshit insane? it really does look like the engine has some wear. Not much, but some. Specially for a turbo

OP. Can you touch the cyl wall and feel the scratches? can you feel a little bit the scratches with your skin? Its the best method to figure out extreme wear without specific tools. If you can feel the scratches, that cyl head its absolute fucking gone.

>Veeky Forums doesn't give a fuck about people that legit know their shit about cars
Yeah that's how far this board has fallen

I have no idea what the previous driver was like - I can only judge by the quality of work in the rest of the car, and my opinion is negative.

I couldn't catch anything with a fingernail, with the exception of the very top of the cylinder, so faint I almost missed it

Top of the cyl wall is no exception. The color was a negative image. If your fingernail gets some dent in the scratch that's fucked up.

If the issue gets biggerr, part of the burn can get there and make you loss compression while worsening the cyl walls.

i'd say its time for an engine rebuild, maybe look into improving the 2jz while you are at it. Specially the oil and cooling. (just dont be an idiot that gets an oversized radiator)

Just typical galvanic corrosion man.

If you can get a finger nail in it, carbon will eventually build up there and you will get hot spots and pinking. Take it to an engine shop if you already have it out of the car

>user doesn't know what a dingleball hone is and doesn't understand it's connotation
not open but please splain.

Time for an LS
As an added bonus your car will actually be able to turn

mark on cyl wallalmost looks like 1 of the oil rings wasn,t compressed when the piston was refitted.
remove and check. do the bottom end.

...

Bore out the cylinders and get bigger pistons
Sometimes you can turn bad things into good things but this time it's just time and money welp

>Kakimoto

Naisu

You seem awfully certain for someone who has only seen 2 photos of light fouling and when the bottom end clearly runs okay(hence op wasn't planning on doing bottom end). Might you be an idiot?
But that makes it sound like it would only occur in the pump.

>not knowing how to filter tripfags

At some point in time someone took the engine apart, almost certainly not for fun but because something was wrong with it, likely loss of compression because they went in with a hand drill and one of these to try to remedy the issue. It's not something you see on proper engine builds, it's a halfass solution, and seeing that lets me know there are going to be other problems. The rings may not even be the correct size.

>You seem awfully certain for someone who has only seen 2 photos
It's almost as if I've seen hundreds of engines apart

send it faggot

Why the fuck does that picture make me so unbelievably uncomfortable.

It's like an alien fungus. Makes me shiver.

it gives me a boner.

nice fart can

Hone it, new pistons, rings and rods. Don't forget to magnaflux your crank.

>not buying a new crank

Why waste money if the original is fine?

why is there a bunch of shit in the cylinders?

Me too but only when its being used