bass mechanic

is it normal to have a light tappet sound when free revving at about 3k rpm and above?
all the cars i have had previously usually had DOHC and solid lifters, once adjusted, they stay pretty quiet.
not as familiar with push rod motors, i know the LS7 uses hydrolic lifters and i would assume they self adjust.
i have to go back to the dealer when my seat cover comes in anyway, so ill have them take a listen.
have any of you had any experience with whats considered normal on these engines?
the sound is light i can only hear it when the windows are up or if i am in a drive through and the sound has somthing like curbs or walls to bounce the sound back at me.

etarded

My car makes the same noise as did a friend of mines' Z. These things actually have a good size cam from the factory and thus are a bit noisy. (My Opinion).

whatcop?

These engines are pretty noisy when it comes to the lifters.

arkus

What year is your car ?

exukboy

Mines noisy especially on concrete or near other vehicles and walls etc. Park my car on grass and it's as quite as can be! But the noise is not excessive though and I wouldn't single out one particular rocker/valve/lifter as being noisy, they're all about the same. You also have to remember these engines have thin wall alloy block castings and a composite intake manifold which don't help any in absorbing or muffling the sounds of the valve train in motion. If everything was cast iron like the old days you probably wouldn't hear a thing. Also note the injectors sound like a sewing machine which again is perfectly normal.

z0sicks07

they all have slight valvetrain noise ive had my rockers eat up my cam and it sounded like an exhaust leak for about 3 days before the engine light actually came on so....go from there

ufaj26

My 09 is noisey as well.

Vito.A

These engines have hydraulic roller lifters. They are actually pretty quiet. A lot of what you hear is injector noise from these new style injectors in a composite (plastic) intake manifold.

phantom427

its noisy, and there is little to no sound deadening material either, so you really hear it inside the car compared to other vehicles.

bowtiguy

The titanium intake valves have a bit more "tick" to them too. take off the lifter covers andit will be more pronounced. add Titanium exhaust valves and a .700 lift cam like I did and it sounds like a singer sewing machine at times...but runs like hell!

bass mechanic

thanks for the feedback guys, i feel better..

hey someone said its a roller valvetrain? wow! what other kinds of goodies did GM put in this engine? i know the rockers have needle bearings (that sometimes fell out) you mean to tell me that this motor actually has rollers that contact the cam? how about the rocker itself? is there a roller that contacts the valve stem?

and a question for you guys with a cam, how much hp / tq does adding a cam make if everything else is stock?

BearZ06

Cam in otherwise stock Z06:

http://forums.corvetteforum.com/c6-z...ts-inside.html

logan1080

You can only hear mine slightly at idle in my 06' Z.

GMuffley

SilverNotch7

I have a 2006, and the valve train noise is definitely noticable between 2000 - 3000 rpm. My rockers make noise similar to the aftermarket crane gold rocker arms I've had on previous cars. I think it's fine, though I'm going to swap out my rocker arms before going the forced induction route.

hedgehead

Before you get too excited, all modern cars have rollers....but ours is the best!

mirage2991

^ since 1987 GM has used roller cams.
Camaros/Firebirds
GTO's
Corvettes
Traiblazer SS
Impala SS

the list goes on

DanTheFireman

Yep, mine kicks in at 2100 and goes away just as quickly at 2600.

Invisiguard

guys, be VERY CAREFUL with this!

http://forums.corvetteforum.com/c6-c...gine-blew.html

check this thread, 3 of us C6 guys have had lifter failures, mine was at 50k, but two of them were at 30K. Make things worse, you guys use the EXACT same lifters as us. We were all a bit modded but still made less hp and lower redline than any of you guys. If one of these explodes like this and takes out the lifter bore its at the least a rebuild and at worse a whole new block.

heres what I pulled out of my car tonite.

RUN4CVR

I definitely get some noise from about 3K rpm up...as the car warms up it gets quieter but has to be really heated up for it to go away completely.

The strange thing is that it just started a few months ago, after having the car for almost 1.5 years and 14K miles.