[jeremypatton08]

Having some smoking issues..mechanic said either new motor or rebuild..any suggestions

 

[ten-sec Spec]

any other details?

based on no details, my first thought is precat failure, second thought is butterfly screws, third thought is head gasket

 

[i68k]

not much of a description here. what year/model b15? where was the smoke coming from? what color was the smoke? did the motor overheat? did you run out of oil or coolant? need more details for any type of relevant suggestions....

 

[jeremypatton08]

Well the door was grey...coming from the exhaust...I bought it as is and it wasn't doing this...its an 03 spec v...its got a nismo cat on it now....and it is burning thru a lot of oil

 

[i68k]

Well the door was grey...coming from the exhaust...I bought it as is and it wasn't doing this...its an 03 spec v...its got a nismo cat on it now....and it is burning thru a lot of oil

the door was grey? you mean the trunk was covered with black soot? is it smoking grey/black? does it smoke constantly, or just when you rev it higher into the rpm?

you have a nismo cat, like on the midpipe? or a nismo header with cat? if your old header failed, with p0420 cat below threshold, that would explain all of your problems. if this is your problem, the motor is rebuildable, but most mechanics would probably want to just swap the motor instead of rebuilding. you can look up info for the 08+ headgasket and headbolts, and since youll be doing the bottom end, maybe a jwt bsr if you go with the rebuild. a butterfly couldve also done this damage, but with a screw the engine or some internals may not be reuseable. here's the faq:
http://www.b15sentra.net/forums/showthread.php?t=135241

EDIT: make sure you keep your oil & coolant levels up if youre still driving the vehicle.

 

[jeremypatton08]

sorry...stupid autocorrect...the smoke is grey..it smokes a little when first started up and when it reaches around 4500 RPMs...other than the smoking its a great car...and after looking close I guess its just got a Nismo exhaust

 

[i68k]

sounds like you most likely suffered from precsat failure, especially if you still have a catted header on there. usually the ceramic gets sucked back into the motor and scores the internals. you would need to rip apart the motor and examine the damage, most likely your oil rings are flattened out and not pulling oil back down, so its burning and coming out the exhaust. this is a very common problem.

EDIT: always make sure you have checked your oil and coolant levels, the less fluids you have, the more wear the motor will endure