Jon B.

Hello everyone, I recently purchased a new to me z06 and it has pretty much ALL the bells and whistles. It's got AFR heads, FAST intake, custom spec cam, full ARH goodness, the works. The only issue that I can point at though is a really loud valve train. As in, it's plenty audible inside the car at any rpm. I pulled the valve covers for my own sake and everything seems on the up and up. I don't believe it's an exhaust leak either, but that was my initial thought. The car is obviously not quiet by any means, but I don't remember my last z06 being so obnoxious inside the cabin.

So, should I be overly concerned about it? It seems like it's normal "sewing machine" LS sounds only louder. I don't want to remove the intake to check the lifters if I can avoid it. Oil was recently changed and it's not low. I have plenty of oil pressure.

zeevette

I also have Trickflow heads, and I can't hear the valvetrain unless I have the window open, and the stereo off. I also have HS roller rockers. OTOH, the valvetrain is louder than stock.

JRHMUMBL3

I have TFS heads, Dynatech Headers, Fast, solid pushrods, hydraulic roller rockers, Vindicator cam, and all needed accessories. I have no resonators and Billy Boat Bullets..... I can still hear my valve train.


Sounds like our cars are very similar, so I wouldn't worry.

Jon B.

Ok, I definitely can't hear it over the radio, and if I'm on it the exhaust is louder obviously. The car doesn't miss a beat and pulls clean and strong. Thanks for your thoughts guys.

JRHMUMBL3

I was referring to idle. If I turn the radio or get into, I don't hear it. Unless I am at about 4k and let of the throttle to coast. Then I hear it.

zeevette

Sounds like speed to me.

YoungRedZ

I'm stock with the exception of XS Power LT headers and an A&A Supercharger kit. I have the "sewing machine" noise too at low RPM while cruising. Just the price you have to pay with headers I guess. However, I did switch to the straub bushing style trunnions. That seemed to reduce the noise a little, but I can still hear it. It is kind of annoying, but then I just mash the throttle and forget about the noise.

NemesisC5

To be safe, I'd make sure the push rod lengths are correct. I had the sewing machine noise before and later when changing cam saw wear on a couple lobes...likely caused by incorrect pushrod length. I asked a couple shops for their opinions as well like you, both said no worries, they were wrong. If it's enough to bother you I'd check rather than have a chance at a repair bill later. I was lucky I didn't spin a lifter in it's bore at high rpm.

CTD

Noise

Street Approved

Yea the sewing machine sound should only happen in the early stages of the cam (my opinion) I would check on the rockers and push rods...other then that the valve train will be loud as hell.

TXGS507

My 414 stroker is quiet as a mouse (valvetrain). The exhaust is another story...

Laser Guided

I have a 227/234 comp cam, valve springs, pushrods, etc. Definitely noisier than stock.

Jon B.

I do probably need to do this, as I've heard the noise is generally related to the wrong pushrod length. Need to find a pushrod length checker and go from there. I can't have the car down or at a shop though, so it'll continue to get driven.

Already had the covers off to check the rockers and such. Nothing was "off".

Torque Obsessed

I upgraded the springs on my stock heads and added headers and suddenly found myself driving a sewing machine too. Apparently some headers are thinner wall than OEM and they let more sound through. Since the car was also super loud with cam/headers/high flow cats, I pulled the interior out and added sound deadening throughout. That helped a lot, but I could only reach so high on the firewall. I can still hear it a bit but it's a lot better. I'll be switching out the headers for a turbo setup this winter and am hoping things will quiet down then.

Hib Halverson

I have Crane 1.8 rockers, Crane dual springs and Crane pushrods in the LS6 of an '04.

Valve noise is slightly more than stock.