4.3 noise?

[CheezWhiz]

Hi,

I've got a 2007 Silverado Classic, 4.3 5 speed, 28k miles. I was running 5w30 dino and just changed recently to 5w30 Pennzoil synthetic.

I don't think the oil change to synthetic CAUSED any problems but now I seem to have a tapping noise? Is it possible that the synthetic, being thinner when cold than the dino oil, revealed a piston slap problem or something of that sort?

I'm confused because the 4.3 V6 is generally regarded as quite problem free, albeit underpowered and with not-so-great gas mileage.

Should I drain a quart or 2 and add some 20w50 dino oil to see if it goes away?

 

[jldcol]

Was the filter the same kind between the 2 changes? this is often a cause of a different cold/start up changing of sound or vibration. The description is vauge enough to be a valve lifter or a piston rock thing, the piston aparently is less changeable by oil than the valve lifter.

 

[duaneb9729]

is the noise there all the time? or just when its cold?

how many miles on this oil change?

did the noise come on right away at the last oil change or after a few trips/or miles?

 

[tig1]

When do you get the noise? On start up, cold engine, hot engine?

 

[CheezWhiz]

Filter isn't the same, think I used an AC Delco this time and took off the Jiffy Lube job. Only a few hundred miles on this oil change but I didn't really listen after the oil change so I can't say if this just started or if it started with the oil change.

I may go start it up and listen to it, let it warm up and see if it goes away. Not sure if it is there when hot or not.

 

[05Blazer]

CheezeWhiz,

I have the same 4.3 5-Speed setup in my '05' Blazer and know the exact tapping noise you speak of that occurs at cold startup and comes and goes at idle. I also have 29k miles so an identical setup! I have used Mobil 1 Super Synthetic with Mobil 1 EP filters since day 1 and have had this noise. Due to recent oil line leaks in the cooler lines I have switched to Maxlife Blend 5W30 and haven't heard that noise since. Coincidence? Maybe, but I used the same Mobil 1 EP filter and will stick with this highly regarded oil from here on out. The truck idles and sounds much smoother. My suggestion is run the current fill to get your money's worth, and then try the MAxlife!