RandomSSHero

iTrader: (1)

The 04 GTO started doing this today. We're unsure what it's coming from... lifters, springs, rods, bearings??? It does this at idle and when rpms increase it gets faster. Warm or cold, doesn't matter. The car is in a parking lot and trying to figure it out to determine if we can fix it there or not.

Stock internal LS1, 55k miles. Camshaft: 232/236 FTI Custom Camshaft. .600 lift. Heads: Z06 #243 casting. These have the lightweight sodium-filled valves. Professionally installed Patriot Dual valvesprings.

Video: http://www.youtube.com/watch?v=H0xdm6Md5y4

Thanks!

9000th01ss

iTrader: (10)

Thats a blown rod or dropped valve. Do a compression check, look for cracks in the block and pan.

1SLwLS1

iTrader: (6)

I have no idea, how much of a pain would it be to remove the valve covers to see whats going on under there? Not necessarily running the motor, but turning the crank by hand or what not.

406malibu

wow, thats painful to listen to... sounds like something in the top end tho, just dont keep running it, or it'll cause more problems.

RandomSSHero

iTrader: (1)

anyone know what tools we need to pull those valve covers off on this 04 gto??

01 Trans-Am WS6

iTrader: (5)

Ouch, sorry to hear that man.

CTSV_510

iTrader: (1)

just a rachet and some sockets - there's only a handlful of bolts on each side for the coil packs and the vavle covers.

pull those off and take a look before you run it anymore.

ghardester

Pull the plugs first and see if they tell you anything. And man, don't run the engine anymore. I agree that it sounds like the top end, a rod or bearing makes a knock.

araber89

iTrader: (3)

Use the write up on install university that is for painting your valve covers to take your coil packs and valve covers off. Also that write up is for perimeter bolts but everything is still the same for your center bolt valve covers. I'm gonna say you should get a flat bed and truck pull it home that way you have your tools and garage to work in. All it takes is sockets to remove everything but still get it home.

9000th01ss

iTrader: (10)

What was the piston to valve clearance when the cam was put in?

No offense but if you have to ask how to get the valve covers off, you're better off taking it to someone who can complete the job and fix whatevers causing the noise.

candlelit

iTrader: (21)

that's my buddies car.

we didn't need to know how to take off the valve covers, pretty much common knowledge. we just needed the right sizes of the nuts so we wouldn't waste spending money on the wrong tools.

anyways. we took off both valve covers and the 2nd from back passenger rocker wouldn't budge (we cranked it over but didn't let the car start), all others worked. we pulled the pushrod and it looked fine, from glance the others did too. oh, they are TX SPD hardened pushrods, 7.425

any ideas?

9000th01ss

iTrader: (10)

I'm trying to picture this, so you're buying tools as you need them?
Ok, odd but it'll work.

How many miles on the cam?
What was the piston to valve clearance?

You know what **** it. You're asking for advice and not giving follow up answers.
Pull the head off. You could check the compression on that clyinder but it'll probably be zero, and I'd guess you don't have a compression gauge.

It's a blown rod or there was PTV contact, maybe both. Either way, you need tools, or take it to a shop. This engine needs major tear down work, and if you're buying tools one at a time,,,well good luck.

candlelit

iTrader: (21)

I actually have tools, and so does he, but they weren't convenient where we needed them. I didn't give you any following answers because I don't have an answer for them, plus I was in a rush earlier, sorry. I don't know how many miles are on the cam, and I don't know what the PTV clearance is.

Thanks though, I appreciate your input!

9000th01ss

iTrader: (10)

Well it's good to hear you have tools lol. It sounds like you're going to need them.
Good luck and hopefully it's not as bad as it sounds.


Was the pushrod loose before you took it out? can you tell if all the valve springs are the same height?
It sounds like either the lifter lost its guts or the valve head broke off.
Still odd that the push rod would be straight if it were either of those.

candlelit

iTrader: (21)

what do you mean by "loose" pushrod? are they supposed to be tight in there? I remember when we pulled a few of them, from both sides, didn't notice any effort changes pulling them out. The springs, from what I could tell, looked like they were all ok. I think tomorrow we're going to start tearing into it a little more, like at least take the heads off. I'm kinda also thinking it could be a lifter (they're stock lifters), and he's thinking perhaps its a problem with the cam. kinda hard to tell by not tearing it down yet lol

1SLwLS1

iTrader: (6)

I think he was asking if they were loose before you removed the rockers. They should just slide right out once the rockers are off

9000th01ss

iTrader: (10)

Yes, I meant before the rockers were removed if the pushrods were normal.
Like the one with the rocker that doesn't move, the cam lobe has to be doing something, if theres anything wrong with a lifter theres going to be a lot of slop in the push rod, or it's going to be jammed tight. Checking obviously with the lifter on the base of the lobe, a few turns out on the rocker bolt would loosen it in a normal situation.

If theres a rocker not even moving I would suspect a ton of slop in the pushrod, like being able to move it up and down by hand as soon as the valve covers were removed.

BayareaCobra

Drive it into a wall going 120mph, no more noises.