New VMax owner with a question

v2500 · January 20, 2014

Bought this truck recently and so far love it! Been enjoying driving it.. until last night I hear a tick noise in a drive through. I thought I might have the dreaded L76 lifter tick, but listening to the valve covers, valve cover bolts, and exhaust manifold ports with a home made stethoscope I didn't hear anything other than normal valvetrain noise, no one cylinder stood out so I'm assuming that's not the issue.

It almost sounds like a serpentine issue until you get under neat the drivers side of the truck and it's very obvious.

I made a video of the noise.

What do you guys think? This LS is a new beast to me, my last Chevy had a TBI 350 in it.

So far I love the truck. Has 63k on the clock and drives super nice. Wife hates the gas mileage but I'm happy with the 13.5-14mpg I've managed so far(hand calculated).

My plan is once I have the maintenance up to date(Dealer says 100k on the transmission fluid... I say yeah right I'll do it myself asap) to get a Black Bear Tune and a Ready Lift leveling kit and drive the heck out of it.

MS3DALE · January 20, 2014

Mine has a similar noise,although a little quieter,been that way since new,I have 45k on it now.

mike94silverado · January 21, 2014

I take it that it's out of powertrain warranty then? Otherwise is take it in but most of the work trucks here do it and have since new

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v2500 · January 21, 2014

Thanks guys. I have another month left o fmy warranty. I'm going to try and narrow down the noise underneath. It doesn't get faster as the truck revs, almost goes away.

v2500 · January 21, 2014

I found the issue... lets see if the dealer steps up and backs up his CPO warranty.

Drivers side rear exhaust manifold bolt is either broke off or missing. I couldn't get up there to see if there was any bolt left in the head. I've only had the truck barely a week off their lot and the dealer in question is supposed to be one of the better Chevy dealers.

v2500 · January 21, 2014

Here's the culprit. Definitely broke or missing.

The dealer is going to fix it for me. Once that's done I'll be writing a nice review of them since I planned on writing a nasty one if they didn't. You always hear about the bad, but rarely the good in the dealers.

v2500 · January 23, 2014

Spent all of a half an hour at the dealer. They looked at it and sent me off with a free loaner. They're going to pull the manifold, extract the bolt, inspect the manifold and replace if need be, and replace the bolts and gaskets on the drivers side. Decided to have them flush the coolant while they had it in their possession.

I'm going to purchase bolts and a gasket and hope the passenger side bolts come out without too much problem. I want to replace them before they break.

govener71 · January 24, 2014

Sounds like a good deal. Free parts and labor are always nice.

My only thought would be if you replace the other side and twist off a bolt head, it can be a pain to do the work. That might be a good thing to do when your out of the warranty period just in case it does break on its own.

v2500 · January 25, 2014

Got the truck back. It's a lot quieter. Dealer tech decided to pull the head which also means I have all new gaskets and bolts on that side. They did a good job taking care of me.

Still got a noise that's bugging me. Still can't hear anything with the stethoscope from the valve train or lifters other than "normal". Pulled the belts since I know they both need changing and the tensioner is a little noisy..

.

I'm hoping it's still exhaust related since it's underneath the truck.

v2500 · January 25, 2014

Driving it today I heard a noise similar to a woodpecker chatter or even a muffled jake brake on a semi coming from the engine bay on a deceleration and within 30 seconds the CEL came on. Pulled the code and it read P1174 code(Fuel Trim Cylinder Imbalance). Same code I had when I brought the truck into the dealer. I have an appointment scheduled for Monday to drop it off again.

v2500 · January 27, 2014

It's back at the dealer. I hope this stuff gets figured out before my CPO warranty is up

I had the chatter noise happen on the way to dealer, it occurred on deceleration from 75 to 70 after passing someone. It happened at the same time as AFM kicked in. Told the dealer this...