: Rod knocking on cold start up



treslados
03-06-09, 11:02 AM
Took my 06 Nstar, 38k to the dealer cause after sitting a couple o weeks upon start up there was a loud kncking sound, as if the rods were knocking..
Dealer sez nothing is wrong...Any others experience the same problemo?:cool:

RobVuk
03-06-09, 12:34 PM
Took my 06 Nstar, 38k to the dealer cause after sitting a couple o weeks upon start up there was a loud kncking sound, as if the rods were knocking..
Dealer sez nothing is wrong...Any others experience the same problemo?:cool:

Mine wasn't necessarily a rod knock sound but lots of valve train noise for about 5 seconds. It was a stuck pin of some kind on the camshaft mechanism that maintains oil pressure until the pump catches up with the system. Fixed under warranty.

King3244
03-06-09, 11:37 PM
Know problem on the N*'s.....has to do with the timing chain tensioner's....warranty item....have your dealer check service bulletins.

LXWXHT
03-09-09, 10:09 AM
V-6, 2005, 30k, mine will knock until the oil gets to it. After it sits for a few days at a time. Seems normal. General Motors.

johnb21
03-10-09, 09:06 PM
i have 85k on mine and get a rod knock sound as well at cold start up. i live outside of Boston.
have you concluded on yours to be chain tensioners? man, i never would of guessed that...sounds like a rod starving for oil..the noise does go away after it is warm.

treslados
03-11-09, 12:20 AM
Thing is, it was only cold for like a coupla days.
The techs were never able to duplicate the problemo cause it stopped being cold. The adviser wrote down the Cadillac complaint line and said if I called in, GM would open a file, then, even after my warranty wore out would:yup: still honor and fix the problemo because of the documentation. Now, where is that number...?

73Thumper
03-12-09, 11:48 AM
My 07 had the same issues, at 6k. It was not a rod knock - although it was loud and that is what I thought it was. It is the variable cam phasors. If they leak any oil internally, and then at cold start it will take a few seconds to rebuild that pressure in the cam phasors. In the meantime until the pressure builds, it is very noisey. It will be worse the longer it sits, If I didn't drive it for a few days - it was so loud I thought she was going to blow - but it would go back to normal noise within 10 seconds. It took the shop several days to fix as the parts are not stocked - and it is a big job under the hood ( I think they replaced all four - 1 per cam)

Paulie Walnuts
03-23-09, 09:38 PM
hey - got this one - it's bad or stuck phaser(s) - they throw oil on the cam shafts at start up for quiet turns - when shot or stuck - you get the "growl" - no damage - just scary after used to quiet starts. Replaced once under warranty - now with 99K miles - it's so intermittent I don't mind it.