can just the rings in one cylinder go bad? why would this occur, especially since there were no problems or oil consumption recently?

 

Normal wear out tends to be gradual with about half of the cylinders going over the edge when the beast gets ready to die. Compression loss in all with a couple being very bad.

If you only have 1 that went south and all of a sudden, I hate to be the one to say it, but it is probably detonation. ! or 2 cylinders always run hot or are a little lean. Detonation does its dastardly deed there. Broken ring lands, hot spots, ring groove wear and taper, etc.

Good luck.

Regards,
BigMoose

 

wasnt running lean, A/F was 12.7:1 and timing was at 16 degrees base timing running 11.6:1 compression and 93 octane gas. i have never had any detonation with my car at all. could it be normal wear and tear?

 

Did you run a compression and leakdown test? How do the other 3 cylinders look (compression wise)? Your first post never said exactly what symptoms you are getting from the "one bad cylinder."

Give us all the data you can, and I'm sure the folks here will give you some opinions. Did you change anything lately?

Regards,
BigMoose

 

changed the headgasket last week and the intake as well with that. the spark plug in cylinder 3 is covered with oil deposits, the other spark plugs look fine. car blows whitish blue smoke on partial throttle in gears 1 and 2 and thats it. doesnt smoke on highway and i have had people follow me during the day and night on the highway and no smoke. car runs great and idles fine. gets good mpg and no coolant appears to be missing. havent done leakdown or compression tests because i dont have the tools. took the header off today and the exhaust port on the head on cyl 3 was very dirty with oil deposits. the other exhaust ports looked very clean and polished and i have just had the head milled 10 thousandths. hope this all helps. now i need some help

 

Detonation will kill ring lands if it happens enough. I've seen plenty of turbo cars with broken ring lands including a twin turbo NSX I tore down last week. Check the pcv hose from valve cover to intake pipe for smoke at idle. Did you inspect the cylinder walls while the head was off. You can usually see vertical scratches on the walls from it. Go rent a compression tester and check it out. Why did you change the headgasket?

 

i had headwork being done and you are supposed to change headgaskets

 

If you have one plug and cylinder coming out oiley, it's probably bad compression in that cylinder. If you just had the head done and still have the problem, look to the rings or the cylinder walls may have become out of round.

 

i think its the rings. let the fun begin