I have what sounds like a lifter tick on the driver's side of the engine. It's very noticeable when accelerating, and also when downshifting in manual mode. I noticed it about a month ago @ 23K miles.

I was running Mobil 1 5w-30 when I noticed it. I was about due for an oil change, so I switched to Castrol Edge 5w30 synthetic. I'd say it's a little quieter but not by much.

I'm also noticing a rough idle...not that rough, but it idles around 600 rpm when warm and then every 10 seconds or so will stutter for a second. I've checked the connections at the intake tube...nothing wrong there.

Anything else I could try before taking it into the dealer? Only mods are a Corsa Sport cat-back, Airaid MIT, and K&N drop-in air filter. Truck is a 2012 GMC Sierra Denali 2WD.

 

Grab a mechanics stethoscope and poke around on each bank and see where the noise is coming from, that can help track down what the sound may be.

And for the rough idle I am just throwing this out there, but what if your k&n filter had a little too much oil on it and misted the MAF sensor with oil and now it's dirty and could be reading slightly off. Cleaning it with maf cleaner couldnt hirt.

 

Good stuff. I'll have time to do both tomorrow after work.

 

Yeah I was thinking this also , oil on the MAF . Good place to start .

Have you had your TPS replaced under the recall ?

 

I have a 2010 GMC Sierra CC w/ the 6.2L. I have a K&N filter and Spintech replacement muffler. I also run nothing but Mobil 1 5W30 in all of my vehicles. This is my 7th GM vehicle and the 4th V8 that I have owned since brand new (Silverado w/5.3, TBSS w/ LS2, GTO w/ LS2, and now my current Sierra w/ 6.2). ALL of the vehicles have had a "sloppy" sound or inconsistent slight lifter tick at and around idle once I switched to full synthetic. ALL of them have had a kinda rough idle.... almost as if it misses every 7 to 12 seconds.. sometimes one right after the other. I have never had an issue and ran the living **** out of all of them!! I put about 40 to 50K miles on the first 3 V8s and I've got 65K on my Sierra.

I wouldn't say totally ignore it but, if the dealer tells you its normal for your truck, I wouldn't discard that as inaccurate either.

Just my 2 cents.

 

Yeah, I’ve dealt with lifter tick in the past, and the dealers around here always tell me it’s normal. It’s just frustrating when it didn’t tick, and one day it started ticking. I have a discerning ear, so I hear everything.

You described the rough idle perfectly. Almost like it’s missing every 10 seconds or so. I’ve even had co-workers comment on it while we’re headed to lunch.

 

I just read up about the TPS. Thank you for bringing that to my attention. I bought this truck used about a year ago with 10K miles, so I was unaware of the service bulletin.

 

If it is lifter tick, try running 1 liter or a 1/2 liter of ATF in your in your engine oil for about 500 miles before an oil change. It is very high detergent and will remove any sludge from the lifter.

I had this happen in my 6.0L G8 GT. Dealer wanted to tear down engine and replace "collapsed lifter". I tried the ATF trick and drove it issue and tick free for another 20,000miles before selling it.

There is another cheap product called "Tune up in a Can"... its also just another high detergent low viscosity lubricant that does the same thing. Its worth a shot.

 

sorry should have posted here as well, but i did post on gm truck.com i had a collapsed lifter and worn cam lobes that were replaced in february. i kept hearing what everyone describes as "piston slap" i was making them aware that i was not happy still. i ended up bringing it in 2 weeks ago and they ended up replacing with a new crate. just got it back yesterday!! i only had 96000 km on it too!!

i used a full synthetic quaker state, which is what the dealer offers. i would complain and push for a new motor. this should never happen to these things. u should be able to whip these things and never have an issue, providing of course you do good maintenance and use proper fuel grades etc.
i would be hounding the dealer!! good luck.
fyi i know gm even offers an additive that is to help with "sticking" lifters. i tried it in my old truck (5.3)
but i didn't have any luck

 

Every LS Ive ever owned starts ticking at some point. Some worse than others. It is annoying as heck, but I cant say its ever caused me any real grief either aside from the noise nuisance. No AFM vehicles here at all

Aftermarket cams compound the volume of the ticking in my experience also. My 07 6.2 was quiet as a mouse for the first couple years even with the EPS cam, but now? Yowza ticky ticky like crazy

Runs harder than ever though