TLDR; cam bearing failure

04 with 23k miles. Hearing new noises all the time. Not always hearing the same ones, but always hearing something. Done a number of searches and have found possibilities for most, but being a newb, figured I'd post up here while I wait for a shop to have an open slot. I should also mention the car seems to drive and shift ok and have good power...but there could be some things I need to service.

First noise is under the hood and more noticeable on cold start. Its kind of a hollow tick sound from the top end around cyl 1/3. And another on back by cyl 8 that almost sounds like an exhaust leak. Also notice a bit of a missfire and roughness to the idle; seen in the tensioner. I just got new plugs and wires I plan on installing in the next couple of days. See if that helps the idle


Second is a noise I'm hearing from the interior only. Sounds like its coming from where the clutch and torque tube are. Kind of light knock sound, but I do not hear it from under the hood. Haven't got under the car yet to have a listen from there.

https://www.youtube.com/watch?v=GTRq...ature=youtu.be

Last is a slight whine that has some fluttering to it. Hard to hear, but its kind of a high pitched sound that has a touch of flutter to it. Cant tell what it is, but the flutter reminds me of a valve train noise...but not with the whine. So not sure what it is

https://www.youtube.com/watch?v=hItg...ature=youtu.be

I'm just wondering if these are normal (if you can even tell from the video!) or if I need to dig into sooner than later. You guys are my first pass before going to the dealership as the two local shops I have are booked 4-6 weeks out. Also, this car went from getting roughly 2k miles a year to being a daily driver if that matters.

Thanks

 

(1st video) For sure hear the injectors, but that's pretty normal. Sounds like a possible exhaust leak on the passenger side.

(2nd video) hard to hear, possible torque tube bushing. Does it make the sound when the clutch is pressed in? does it get louder the faster you drive?

(3rd video) Cant help you on that, thats a new one for me. Would say the rear end but sounds like its coming from the front. Maybe a pulley but not for sure. Sorry i couldnt help more.

 

1st - OK, I'll get the specs and check the torque on the headers. If they have to come off to replace the gasket its a perfect excuse to trade up for some ARH's

2nd - I'll check the clutch in/out today. If it changes with clutch engagement should I look to the throughout bearing? And from what I read, that's more of an annoyance than a must fix asap?
No, I cant hear it when I drive

3rd - I thought rear end too, but its definitely in the front. I wasn't sure if sound would be brought forward by the torque tube? But that sound definitely gets louder during acceleration. Pitch of it changes a bit too. Reminds me a lot of the way my old 03 Cobra sounded under boost; which leans me towards AC pulley system or balancer. But again, not sure.

Thanks for the input

 

Here's my opinion on terrible ipod earbuds. I'll try and listen later with some headphones.

1. Definitely sounds like injector noise to me. Especially with the speed at which it sounds like it's ticking.

2. Hard for me to hear anything as well. I agree with zdeckich, check for the noise with the clutch in/out.

3. I'm saying rear diff. I'm going through the same exact thing on my 02 Z. I get a very distinct gear whine as I accelerate. Most notable in 4th/5th/6th gears while cruising. It does get louder with speed. I had a local shop take a listen and they informed me it was the diff. The sound is brought forward by the torque tube. Does it sound like it's coming from directly under the shifter, or more in the dash?

 

OK, clutch in out doesn't seem to make a difference, but it was hard to hear. I'm going to try again in the AM on cold start. I did however hear a slight noise when in 1st gear. I had the windows down and was next to a curb (turn lane) doing about 10-15mph, and I could hear a slight metallic sound. It didn't necessarily match with engine RPM, but its the first I've had the windows down driving so it could have been there all along.
Both that noise and the whine sound like they're forward of the shifter, in the same spot.

I did stop by one of the local dealerships to see if they had a Vette guy...I now have an appointment Monday morning to take the tech for a spin and have the trans and rear diff serviced. So we'll see what comes of that. Not a fan of dealerships, but I neglected to think about all the Vette's coming out of winter hibernation booking all the slots in the tuner shops

thanks for the input

 

Clutch does in fact make a difference with the whine. If you get your head down by the pedals on idle you can hear the whine, very faint, but its for sure there. Push in the clutch, and it goes away. Repeated for 3 minutes to confirm.

 

probably the slave or pilot bearing.

 

Ok, I'll look into both. I'm sure the pilot bearing wont be cheap

 

My guess is $25. So its cheap, the part that's not cheap is if your paying someone to replace it. If you have to go that far, I would consider changing the clutch since you will be there. my shops charge around $1k to do a clutch job.

 

Yeah, the part cost is easy. And I wouldn't mind doing the labor myself, but no lift and not sure I could get the car up high enough. I have some nice jack stands, but I think they're only 21". From what I've read on here you need a bit more to get the torque tube out.

So if it comes to dumping $1k (best case since its a dealer), I'll definitely put a new clutch in. I just hope if it IS that I don't have to do the input shaft too...I need to drive for the next few days, so that may not help either.

Oh well, hope for the best and plan for the worst.
Thanks again

 

Update:

Had a local Vette shop (Wong's Performance) take a look at the car while they installed new valve springs...they didn't see, hear, or feel anything wrong.
Tom installed the springs, then drove it around and said he didn't hear anything abnormal or alarming. Surprised the hell out of me, because to me it sounds like the most mechanical engine I've ever heard. My LS3 sounded nothing like this.
BUT, with that said, the shop is very well known and respected, so I'm going with "Ship It" and just drive it until it doesn't drive anymore! I'll be doing long tubes, intake, and a tune very soon so maybe that will help with some of the noise.

Anyway, thanks again for help on this!

 

Glad to hear this. I was hoping you wouldn't waste $1,000 in labor plus parts cost to replace the pilot bearing, clutch, and slave cylinder over a slight noise that might not even be indicating a problem.

 

No, and that noise can barely be heard now over what I'm assuming is valve train noise. I was hoping new springs would change the sound, but it didn't change at all. Which was odd to me since I went with dual springs. But the noise is identical to what it was when I got it back from the dealer. And its so loud people hear it in parking lots or driving next to me and look at me like "why are you driving that thing."

So I'm not 100% convinced its not a lifter or pushrod, but it runs great and pulls hard. Just embarrassing as hell driving such a sweet car that sounds like its about to rattle apart!

 

Here is a video I shot of my car nine years ago after installing headers. You will here the same engine noise. My engine held up to nine years of race track use since then. Of course with video, I cannot tell if there is a volume difference between your car and mine. I personally don't really notice the ticking of the injectors when the hood is closed.

 

That's funny, I cant tell you how many times I played that video after I got my car.

The sound at idle seems to very normal, its the sound at 1500-2500rpm when cruising under light load that freaks me out. I'm going to get a better video hopefully this weekend or early in the week.

Thanks for chiming in with the video

 

Ok, got a better video of this ticking noise. The video is long and boring, but you can hear the tick, rattle, slap, whatever you want to call it.

I taped the mic to the weather strip for the engine bay between the brake booster and driver side head just under the hood. The camera is just sitting on my dash, didn't have a mount so the RPM's could be seen.
Anyway, still does not sound normal to me....

 

still sounds like an exhaust leak and injectors to me.

 

My car certainly doesn't have any noise like that under those driving conditions. My best guess would also be exhaust leak. Sometimes the tell tale soot is only visible after removing the manifold. Assuming you still have the cast manifolds, just take them off and have a look. IIRC, they are easy to remove.

 

Not and exhaust leak, and I tried to narrow in on the injectors, but it sounds lower. I dont have a stethoscope, but they're hopefully coming off tomorrow and a buddy of mine can get them tested/flowed pretty cheap.


Yeah stock manifolds, and no soot. Gaskets looked perfect and everything on the head looked fine.

I did however notice something odd on the rocker for cyl#5 Ex; the surface of the arm that pushes the valve stem, has a circle stamped into it. Almost like there was some lash between the two surfaces and the rocker arm was losing contact and slamming down into the valve stem.

I wrapped up for the night, but I'll be checking the push rods and pulling the heads tomorrow to check the lifters.

 

Found the problem. This is a cam bearing. The second one in from the front. I'm guessing this is where the noise was coming from. Not sure why the oil pressure didn't reflect this, but oh well, mystery solved!