: Knocking On My Northstar Engine 96 STS Sevile

05-03-07, 04:13 PM
Hey guys I need serious help, just the other day my engine started knocking, so i brought back home, i was a little low on oil but not enough for it seize or anything like that. I would usauly the engine needs to be replaced but the knock isnt their all the time, only when i start it up and when its in low gear, if only could help with any ideals that would be great


05-03-07, 04:36 PM
Search the archives and technical threads for "knock", "carbon knock", "cold knock" and a few other N* quirks. Depending on how you drive, you may have a carbon buildup which, in a N* with minimal quench area above the piston, leads to a cold "rap". A few judicious WOT runs may clear the situation. The other possibility is some sort of fuel/timing glitch. Pull codes and see if there is a timing/PCM code set. Did you just fuel up ? Try a tank of 93 with a slug of Chevron Techron fuel additive from your local station or auto chain store. Running a N* a quart low is not normally cause for concern - I habitually run my '02 a half quart low and have essentially zero oil usage. (3000 mi.+/qt.) One of the main jobs of oil in a N* is for COOLING!

05-03-07, 05:15 PM
Thanks Sub, Ill Look into the carbon Knock Thing,

05-03-07, 07:01 PM
If it is only at cold start up, sounds like dry lifters and goes away in 60 seconds or so, the problem is cold carbon rap. The cure is WOT.

05-04-07, 07:37 PM
I have a 94 SLS N* VIN Y, had the same symptoms, hard knock when at idle, no knock when at speed or hard acceleration. Was unfortunately a spun bearing, I replaced with a used motor, to costly to rebuild. Good luck!!