Since I Didn't Receive Responses on Another Forum - I Will Ask Here!

[ZGOBYBY]

I asked this on my GTO forum, and didn't really get any responses. So I figured I would ask my LTx buddies!

About a month and a half ago I threw a cam in my '04, and a week prior I threw on a new driveshalf due to a carrier bearing failure. Obviously with that being said, my SLP LM1 catback had to come off. I didn't install it back onto the car until after the cam install was complete.

Now, I drive the car for about 15 minutes and a faint ticking begins (once it warms up, it's like clock work) and begins to get louder, and stays consistent with the RPMs. Than after about five minutes, the ticking goes away completely. It comes and goes throughout the duration of my driving once it starts (about every 10 minutes... sometimes longer durations in between). On cold starts, there is no noise. I pulled the valve covers and everything looks to be in good order.

I tightened every exhaust clamp possible, and replaced the exhaust gaskets in between the cats and the catback system in order to rule out a leak there. My clamps were loose before, but they are as tight as can be and I still have the sound. It really doesn't sound like it's coming from the engine, I have normal valve train noise coming from there.

Any ideas would be greatly appreciate!

[BLK95-Z]

Did you replace the lifters? How many miles?

[ZGOBYBY]

I didn't replace the lifters. I understand that it is possible that I had a lifter failure right after the cam install, but I'm not sure how likely that is.

[YZF]

You could run some seafoam in the oil. I've gotten several 4.3/5.7 Vortec engine lifters to quit tapping with seafoam. Dump it in and let it idle. The truck motors usually get quiet in 30-45 seconds. Its like magic. Just be sure to change the oil shortly after.

[ZGOBYBY]

Yeah, I may do that. In the least, once it smokes out of the exhaust, it will show me where my exhaust leak is. LOL... any other ideas?

[95ImpySS]

I recommend jacking it up and listening around. Use a screwdriver on your ear to listen to various spots. Oil pan, engine block left and right side, valve covers, various accessory, and the transmission. Does it do it wile driving or idling? Use a rubber hose and listen around the header flanges for exh leaks. Check emissions connections, EGR connections. How radical is the cam? Can the springs keep up?

[ZGOBYBY]

I will put it up this weekend again. I have had it up about fifteen times now. LOL... I pulled the valve covers about a month ago and I didn't see any spring binding issues, and checked all the rocker torques, which were fine. I have LS6 springs from an '05 CTS-V (late model LS6 valve springs are good up to a 575-580 lift). My cam is somewhere in the .53X/.53X lift.

At cold starts, I do not hear it. After about 15 minutes, it starts and than just goes away. If it's making the sound while I'm driving and I come to an idle, it with quietly do it at idle. I do have a "gross evap emissions leak" code right now, which I know probably unrelated (it's just causing me to not be able to fill the gas tank - vaporization).

[95ImpySS]

I have no idea how the LS valve train is set up. Does it use guide plates? I had an issue once using guide plates. Thoe I had major cyl head issues.

[ZGOBYBY]

Yeah, I believe I have guide plates under the heads.

[chevymec]

I replaced the rockers on my 86 that I had and after that I would get a ticking comming from the valvecover. I didnt notice that the rockers that came off were SA rockers. I had out NON SA on so I swapped them back problem solved. If you still think the exhaust is the culprit, find someone with an EVA smoke tester and have them smoke the exhaust. It will show any leaks.

[ZGOBYBY]

Yeah, I honestly think it is my exhaust too. The sounds kind of reminds me of one of those old crappy trucks driving down the highway with a ticky tick tick exhaust leak. But this is exhausting me... LOL. I'm liking the sound of this EVA smoke tester, that may work for me.

[95ImpySS]

Well You can try sea foaming it and looking for smoke and exh leaks. Usually exhaust leaks go away when they warm up...

The problem I had was my push rods were bottoming out on the bottom of the "U" where the push rod rides in the guide plate. During the actuation of the valve the push rod would be pushed out of the lifer cup. Causing a distinct clicking noise as it went in and out of the lifter.... Would only start clicking when the engine warmed up. Never did it on a cold start. And only the number 8 exhaust did it...

[firebird_1995]

You say the sound comes around like clockwork. Could be an emissions equipment solinoid switching on and off.

[ZGOBYBY]

Hmmmmm... that's a good point. I may have to check that. It's probably my canister purge.

[ZGOBYBY]

Okay, so here's an update to this situation. I had Brett take the GTO to a local, very reputiable exhaust shop by my house to check for an exhaust leak. They stated they couldn't find one, and that if a leak is there, it shouldn't start after about 20 minutes or so. So I guess we are ruling that out.

So I am not sure really where to go with this. I drove the GTO home last night, it took about 40 minutes. Once I got on the expressway to drive home, it did it the entire time (about 30 minutes). I am packing the GTO up in the garage for the winter with the Camaro.

Only thing I feel that is slightly off with the car, is I feel something slightly loose through the clutch petal when I let out. Brett said it could possibly be a fin broken off my pressure plate. I'm kind of at a lose now with this car. I just installed a Hurst Competition short throw in it this weekend. The car runs like a dream, there is absolutely no power lose at all, and shifts fine.

Any ideas would be great. I really don't want to have my GTO in the same condition my Z is in because of retardness (not that I am unknowledgeble as to what happen to the Z... that was an obvious issue, LOL).

[95ImpySS]

Have you tried...
...jacking it up and listening around. Use a screwdriver on your ear to listen to various spots. Oil pan, engine block left and right side, valve covers, various accessory, and the transmission.
Listen hard and see what part of the car creates the loudest sound. You can use a stethoscope instead of a screwdriver. In fact I recommend it over a screwdriver lol

[ZGOBYBY]

I picked up a mechanic's stethoscope yesterday, so I will use that.

So, figuring laying on the couch and being lazy was not such a productive thing to do, I decided to head outside and peek at the valve train of the GTO again. Cylinder 6 and 8 pushrods were very clean, but 2 and 4 had a lot of baked-on oil. I thought this was strange... All pushrods were straight, no bends. And there does not seem to be any collapsing lifters.

Here are a picture of the push rods (sets for 6 and 8 are on the left, 2 and 4 are on the right).

8025

As for cylinders 1 through 7, they had the same baked-on oil. I just found it odd that 6 and 8 were pretty much clean, while all others were pretty soiled.

[BLK95-Z]

If its not the exhaust maybe the bigger cam and stiffer springs caused one of your factory lifters to start making noise?

[CamaroZGuy]

is there any way to get a video of the "ticking"?

[jaysz2893]

I just started having this same phenomneon. I put in a smallish cam with new dual springs and full roller 1.6 RR's. I used poly locks and all seem fine. After she gets hot I get this ticking noise too. I have checked all the exhaust clamps and the header bolts are wired and all tight. I dont see a leak at the header flange.. I am stumped too... I am interested in the outcome of this.

[ZGOBYBY]

I will try to take a video and post it up if possible. I will try to listen this week to see if I hear anything through the stethoscope.

[firebird_1995]

What do the ends of those clean pushrods look like? If for some reason oil wasn't getting pumped up to the rockers, they could make noise. Also, the ends of the pushrods would have a kind of swirl grinding on them from riding around with no oil. I tore down a 5.7 Hemi engine that had spun a cam bearing, which plugged off oil to the top end, which caused the pushrods to run dry and do just that.

[1994Z28]

It woukd appear that oil isnt being pumped up through those pushrods. I have never heard of a lifter failure problem in the LSx engine with a cam and spring swap. I know your cam doesnt have alot of lift but that doesnt mean the ramp rate isnt to aggressive for those LS6 springs. DUration means just as much if not more than lift when it comes to the right spring. Its hard to pin point really without actualy hearing the noise.

[ZGOBYBY]

Yeah, that's what I'm saying 1994Z28, I doubt a lifter failure. The contact ends of the pushrods are shiney and silver from what appears to just be normal wear, as opposed to the rest of the pushrod.

I really wish that the GTOs came equipped with an oil pressure gauge. During the cam install, I made sure that I checked the rubber o-ring in the oil pick-up was on correctly, and was not lop-sided for that reason, because I know a lot of people look over that, which results in oil pressure lose. I need to check the oil pressure for sure.

[gregrob]

My LS car does the same thing... but if you pop the valve covers the valve train is dead quiet.

I'm convinced it's a shitty weld on the merge collector of the headers.

Try to get it in the air, and get under there and really inspect the exhaust closely, and you'll probably find it. May even see a faint soot trail at the location if it is a leak.

[ZGOBYBY]

Brett had the car up in the air at an exhaust shop on Wednesday, and they said they didn't see any leaks or hear any either.

[CALL911]

Exhaust leaks will be heard on a cold start just as a warm one. I don't believe your problem is an exhaust leak.

What we need to do is find out where it is coming from. You say the noise can't be heard until it warms up. This makes me think that it is coming from something that is triggered once the car goes into closed loop. Is there any way you could get a scan of the car and see what it is reading?

[ZGOBYBY]

The only code it throws is a evap emission leak, which the vent solenoid is made. It's preventing me from filling up my gas tank normally because it won't vent out the vapors in the tank. I highly doubt that this is the issue. Other than that, I'm not throwing any codes.

As for datalogging, I don't have any issues. Hell, even Mr. Phil tuned the car and datalogged it, and did not see anything off at all.

On a side note, I just had the police show up to my building for a resident assaulting another resident with his beard. This shit doesn't get any better.

[firebird_1995]

That must be one wicked beard ....

[ZGOBYBY]

I tell you man, this place is nuts.