GalantVR4.org The Mitsubishi Galant VR-4 Forum
Galant VR-4 Forums » Galant VR-4 » Technical Discussions » Help! Piston is oval shape! I can see the rings
Previous thread Next thread

Help! Piston is oval shape! I can see the rings


thedsmguy
Senior Member


Galant VR-4 org Post #: 802550 posted 06/16/09 11:10 AM     Remind Me!  Send Private Message   Edit Post      
A couple questions.


I took off a head for a friend last night assuming he had a popped headgasket. Turns out headgasket looks fine and the piston itself is ovaled on the front edge and I can see the rings . He was getting massive blowby but I didn't really put it together in my head until I saw the piston.

There is some scuffing of the cylinder wall.

How do I fix this? Can I pull just that piston, and put another used piston in there? I'm assuming I'd need to put a new bearing on the crank, do I need to put all new bearings? How do I get the light scuffing out of the cylinder wall?

Thanks!!

Posts: 1785 | From: Vancouver Washington | Member Since: 03/20/09 | IP: (24.21.77.30) | Report this post to a Moderator

GVR4_1057
Member ++
1057/2000

1604/2000


Galant VR-4 org Post #: 802557 posted 06/16/09 11:28 AM     Remind Me!  Send Private Message   Edit Post      
That is a melted piston right there. You have to for damn sure replace at least that piston . But when mine did that it also scuffed the bore too badly and it took a full rebuild. This is not a small problem..............



Billy B,
1057 Back after 5 years JSB
1604 all fixed again.
1986 Audi 4KQ
1997 BMW E36 328I

Posts: 676 | From: Brucetown VA | Member Since: 09/03/08 | IP: (12.171.68.176) | Report this post to a Moderator

Rausch Galant VR4.org Moderator
Rock Star Status


Galant VR-4 org Post #: 802559 posted 06/16/09 11:33 AM     Remind Me!  Send Private Message   Edit Post      
^ The bore will have to be bored/honed. If the piston is ovaled, odds are the bore is as well. Bearings very well may be fine, but that is neither here nor there, as you're going to have to disassemble it anyways.

Stock bore? You will almost definitiely have to go oversized with the replacements. It's possible that you could still stay within spec, but not likely. If it were me, I would just purchase oversized pistons and head out to the machine shop.


Edit: of you're good with a bore gauge and depth gauge, you can check everything out once it's apart. That is really the best way to determine what is next.



Rance lives here...
Founder of Sold out to BMW Cru, then sold out there too.



Edited by VRausch4 (06/16/09 12:04 PM)

Posts: 12049 | From: Cleveland, OH | Member Since: 12/21/04 | IP: (63.253.227.122) | Report this post to a Moderator

HHIVR4
Aluminum Lung
1280/2000
138/2000



Galant VR-4 org Post #: 802565 posted 06/16/09 11:59 AM     Remind Me!  Send Private Message   Edit Post      
I the cyl wall is scuffed I wouldnt bother trying to replace the piston and get by..It wont last very long that way and will probably cause more damage.

Posts: 5446 | From: Hilton Head Island SC | Member Since: 10/06/03 | IP: (64.20.143.106) | Report this post to a Moderator

fivestardsm
"Savior of the damned and dis-owned"


Galant VR-4 org Post #: 802569 posted 06/16/09 12:05 PM     Remind Me!  Send Private Message   Edit Post      
Quoting VRausch4:

^ The bore will have to be bored/honed. If the piston is ovaled, odds are the bore is as well. Bearings very well may be fine, but that is neither here nor there, as you're going to have to disassemble it anyways.

Stock bore? You will almost definitiely have to go oversized with the replacements. It's possible that you could still stay within spec, but not likely. If it were me, I would just purchase oversized pistons and head out to the machine shop.


Edit: of you're good with a bore gauge and depth gauge, you can check everything out once it's apart. That is really the best way to determine what is next.





+1 Might aswell upgrade while your already tearing down!



VR4 Picture Post

Steve.
. .27/1000 N B
.677/1000 S W
. .#?/2000 S W
.420/2000 B G
1361/2000 N B
1387/2000 N B

Posts: 1699 | From: Middle, Michigan | Member Since: 09/08/06 | IP: (68.188.223.236) | Report this post to a Moderator

thedsmguy
Senior Member


Galant VR-4 org Post #: 802578 posted 06/16/09 12:22 PM     Remind Me!  Send Private Message   Edit Post      
Its not my car, Its a friend/customers that just wants it to run. He's not modding it so he doesn't want to build it by any means.. Very weird, most guys come to me saying they want it faster, this guy just wants it to run good. He's only owned the car 4 days now and drove it for 1 1/2 day before this happened. So, would replacing the block with a running one seems like it would be a quicker move then to pull this one and take it to a machine shop, buy new pistons etc. etc.

YUCK!
And this all started when he thought he blew his turbo, then I thought it was probably a headgasket, now this sucks, I'm supposed to be moving!!!

Posts: 1785 | From: Vancouver Washington | Member Since: 03/20/09 | IP: (24.21.77.30) | Report this post to a Moderator

GVR4_1057
Member ++
1057/2000

1604/2000


Galant VR-4 org Post #: 802585 posted 06/16/09 12:37 PM     Remind Me!  Send Private Message   Edit Post      
^ Yup. Replacing the short block with a good used one is the cheap quick way to get him going again.



Billy B,
1057 Back after 5 years JSB
1604 all fixed again.
1986 Audi 4KQ
1997 BMW E36 328I

Posts: 676 | From: Brucetown VA | Member Since: 09/03/08 | IP: (12.171.68.176) | Report this post to a Moderator

toybreaker Galant VR4.org Moderator
it's peace of mind at 100 mph plus
1990/2000


Galant VR-4 org Post #: 802587 posted 06/16/09 12:46 PM     Remind Me!  Send Private Message   Edit Post   
Be sure to check the fuel system out thoroughly before sending him on his way with a fresh motor.

Sending the injectors out for a cleaning/flow test would be cheap insurance against a reoccurance.

A clogged last chance screen in that fuel injector could have caused that hole to run lean, and damage the piston.



Edited by toybreaker (06/16/09 12:47 PM)

Posts: 3540 | From: Never Summer Ranch, Colorado | Member Since: 04/30/06 | IP: (208.54.14.14) | Report this post to a Moderator


Pages: 1
Previous thread Next thread

Extra information
3 registered and 40 anonymous users are browsing this forum.

Galant VR4.org Moderator:  curtis, steve, atc250r, jcgalntvr4-244, cheekychimp, jepherz, Rausch, toybreaker, iceman69510, pot, FlyingEagle 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled

Rating:
Thread views: 849

Rate this thread


News & Events: News | Events
Galant VR-4: Newbies | General VR4 Discussions | Technical Discussions | How To and Info Archive
Marketplace: Parts For Sale | Cars For Sale | Good Guys | Bad Guys
Community: Members' Showcase

Contact Us | Privacy statement GalantVR-4.org

Generated in 0.069 seconds in which 0.05 seconds were spent on a total of 14 queries. Turbo powered.


Hertz's Galant VR-4 Page