chipped possibly cracked piston

[xlMcMlx DsM]

through further inspection after me and some friends pulled the head off my n/t eclipse, we just thought the rings were fried. but, i just noticed that the #1 piston has a little moon shaped chunk missing near the top. is it supposed to be like that? or is it chipped? can this cause low compression? i need some help

 

[96gsdsm]

Do all the pistons seem to have this moon shaped crack/chip or just #1? How about posting up a picture.

 

[brute]

If just #1 has it, it might be bad. All pistons have areas for the valves to depress into. Post up a picture.

 

[xlMcMlx DsM]

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see, near the top

 

[andytalon]

Nope that is not normal at all that piston is done with

 

[xlMcMlx DsM]

so could this be part of the cause of my car to not start? it wont even pop when we tried to start it. the head gasket needs to be replaced, so im thinking of just getting a new set of pistons and rods, stock b/c its all i can afford right now. but is this the cause of my low compression of 20psi and 48psi in cylinder #'s 3 & 4? or could my head be warped?

 

[96gsdsm]

The gauge should read 170 - 225 psi. Once you measure all of the cylinders, compare them. They should not be more than 25% off. On my most recent test, I got 205-205-210-210. They should all be pretty close to each other. If one of the cylinders is below the limit, you should check some things out. Check if the gauge was inserted properly first. Try pouring a little bit of engine oil in the low cylinder's spark plug hole. Check its compression again. If it goes up, you may have a worn or damaged ring or cylinder wall. If the compression does not rise, you may have a leaky valve seat or leaky head gasket.

That little chip would not cause that drastic of a cyclinder change.

Any of the listed above could be the cause - (ring(s), warped cyclinder wall, valve seat, or head gasket)

 

[andytalon]

Umm, you will only need one piston and a ring job, just when you pull the motor just check if you need a bearing job. You won't need new rods. And I dout you head is warped, you probebly have a bad headgasket, and bad rings, and that piston is definitly done. Just pull the thing and tear it down then you will know everything. Good luck and if you need anything pm anytime and I will get back as soon as possible!

 

[96gsdsm]

How many miles do you have on your DSM?

 

[andytalon]

ohh sorry heh, thought you said warped head. Your wall isnt warped but it may have some scares from the piston, if it does then you will have to bore it out, if they are honeable then you can go that route

 

[xlMcMlx DsM]

Umm, you will only need one piston and a ring job, just when you pull the motor just check if you need a bearing job. You won't need new rods. And I dout you head is warped, you probebly have a bad headgasket, and bad rings, and that piston is definitly done. Just pull the thing and tear it down then you will know everything. Good luck and if you need anything pm anytime and I will get back as soon as possible!

ok thanks man

How many miles do you have on your DSM?

just over 90000

 

[96gsdsm]

It's possible to do this with the motor still in the car, just jack it up nice and high (dont forget jackstands too!) Drop the pan, drop the crank, ridge ream cycl. #1 and remove piston, re-ring and add new piston etc. Definately hone out all 4 cyclinders and ring them too... It's not like your motor's already 1/2 apart anyways . If you do do the work yourself though BE CAREFUL!!! You absolutely do not want to nick things up and keep your block, head and all internal components clean enough to eat off of when they are replaced.

and one final thought... don't forget to torque EVERYTHING back properly, that's how brand new re-built engines are broken a week after they're installed.

 

[96gsdsm]

with 90,000 miles it might be a good idea to bore over if you're planning on modding this thing any more then an intake and exhaust

 

[xlMcMlx DsM]

and another question, would 2g pistons fit in my 1.8?