: Noisy valve train as oil ages?

08-20-11, 10:26 PM
I bought my 2006 N* STS with 46,000 miles on it. During the first cold winter, after about 2,000 miles the engine developed a clattery noise when cold. As time went on, the clattery noise lessened as it warmed up, but was still present.

After my first oil change, it became quiet. Now after about 2,000 miles on the new oil the noise is back, warm and cold. The oil used was Valvoline full synthetic, meeting GM's 4718M oil quality std (as stated in the owner's manual). I had a mechanic listen to it (no a Caddy tech) and he said it is normal valve train noise. My 3.8L Pontiac with 215,000 miles does not have this noise, but is also not a overhead cam engine.

Is this sound normal for these engines? Is this caused by the brand of oil I am using? (I intend to use Mobile 1 next time).

08-20-11, 10:41 PM
My 2006 N* AWD sounds like a diesel at times with valve train noise that comes and goes. The engine is fairly quiet at an idle but starts to sound off at about 1200 RPM. I tried to correlate the noise with temperatures as low as -50F but the big factor was still RPM.

08-21-11, 02:55 PM
dkozloski, mine is more noticable at idle when things are quieter. Does your noise increase as the rpm goes up? What oil brand are you using? I was wondering if an additive would help, like Lucas or STP. But I worry that it might make things worse as the engine is likely engineered to not expect those additives.

08-21-11, 04:11 PM
Mine is quiet as a mouse at idle and the noise goes up with RPM. I use Mobil 1. Don't use additives. Some years ago STP paid the biggest consumer fraud fine in history for misrepresenting their product.

08-22-11, 10:11 AM
What and whose FILTER are you using,
the Mobile One filter , has a built in check valve
to prevent No oil startups,letting the oil stay
up high to lube the cams, etc.
Please consider this !

08-22-11, 09:18 PM
My wife & I both have Napa Gold filters and her 2007 N* makes more valve noise than my 2006 N* (with 20,000 more miles). They both run great.