The Central Hub for DSM Community and Information

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. This is where the DSM platform history is documented and archived. Log in to help us in our mission, and to remove most ads from the browsing experience.

oil on piston

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

orangecrush4g63

15+ Year Contributor
38
0
Feb 27, 2005
pittsburgh, Pennsylvania
ok..recenty spun a rod bearing in my 7 bolt. bought a 6 bolt that was completely rebuilt 5k miles ago. The guy told me it had 5k miles on it whenever he got it. Pulled it out of the car and put in a motor he had laying around. Took it to a machine shop and they said it has bad compression in cylinder #1. I got the ehad off and saw that there was oil on top of that piston. I cranked it over and it has vertical lines running up and down in here and there. Nothing that had any depth whenever i touched it by hand. While i had it crnaked i looked at number 4 whcich had good compression and it had the same lines but even worse. The head gasket was a metal 4 layer gasket and the oil passages looked fine! I was really hoping it was the ehad gasket but its looking like an oil ring. The block was honed 5k miles ago and i dont think these lines should be there but im no genius. Please gimmie some feedback on what may be going on here.

that #1 cylinder was was wet tested but the oil on top was black. He thought maybe that end of the ehad gasket wasnt torqued down right.
 
If you can feel imperfections on the cylinder walls then it is usually hard to get buy just using a hone. If you can not feel them then honing is well worth a try. Either way since you have the head off I would take off the pan and pull the pistons. Try honing the block then install new rings and rod bearings at minim (don't forget your new head gasket). I would defiantly consider replacing the main bearings also while you are in there. You can replace those easily without pulling the crankshaft by "rolling" the bearings out and new ones back in.
 
Add Value - Be Respectful - No Trolling - No Misinformation - Participate Often!
Support Vendors who Support the DSM Community

Build Thread Updates

Latest Classifieds

Back
Top