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exhaust leak or valvetrain?

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Old 07-23-2008, 09:44 PM
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Default exhaust leak or valvetrain?

I just recently installed a 233/239 cam, duel valvesprings, 7.4 pushrods, Pacesetter Headers/Ypipe, new OEM header gaskets.

When the car is warmed up to 210degrees, and the rpms reach 2000 or more, it starts to tick, lightly at first if you only go to 2k every so often, but if you go through 3 or 4 of the gears in a row, it gets louder. We retightened the header bolts, had the Ypipe welded to the headers, had tightened up the front o2's.

When it starts ticking...if I keep the car under about 1500 rpms crusing, the ticking goes away, but once you do the 2-3 straight shifts to 2k or more, the ticking returns.

Is it an exhaust leak, or is my valvetrain not getting oil like it should? oil pressure stays around 40, oil level is good as well.

Any suggestions? Im about to pull my hair out. We checked around the header tubes, don't see any soot to indicate a hole in the headers either...
Old 07-23-2008, 10:53 PM
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Im not saying this is your problem but i was searching around on the site today and there was a lot of people complaining of a tick like what you're describing. It turned out it was the damn o-ring on the oil pickup tube. I guess gm now makes an upgraded, thicker BLUE o-ring that will solve the problem. Usually you would see lower than normal oil pressure but not always.

You could also try pulling the valve covers and see if you have a loose rocker or possibly a broken valve spring..
Old 07-23-2008, 11:17 PM
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Get a little hose and move it around spots that you might think there might be a leak. But keep the other end by your ear... you will hear and feel the little air if there's a leak. Also did you tighten everything to specs. When I installed my cam ppl told that a common thing that ticks are the roller valves or something like that.
Old 09-06-2008, 11:47 AM
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Alright guys, TTT with this....This ticking still occurs, Im going to try and put a longer pushrod (7.45) in and see if it clears up the ticking at all. I put in a heavier weight oil as well (10w40), but I just changed my oil with the old 5w30 coming out, and along with it was small metal shavings in the oil...this is the second time its done that.

Any ideas as to what the deal is? We thought it might be the pushrods were too short, or perhaps one of them is bent?


Also the ticking now commonly occurs when the car is at a constant RPM crusing down the road...usually between 1500-2000rpm.
Old 09-06-2008, 12:22 PM
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pull the valve covers if you have not yet . if you got a bent pushrod you should be able to tell pretty easy . an aftermarktet valvetrain is going to make some noise .
how long have you been running this setup and how long has the ticking noise been occuring ?
Old 09-06-2008, 12:48 PM
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Ive had the cam in there since the end of july. Its not a normal ticking though...its LOUD. and its only coming from the driver's side it seems. It sounds like an exhaust leak, but it isn't. The car doesn't make that loud tick when its cold, only when the car is at a constant rpm driving down the road.

We pulled the valve covers about a week after the cam install, didn't see any problems with the pushrods, visually. no metal in the head, or anything like that either. its got me puzzled and worried.
Old 09-16-2008, 06:05 PM
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changed the pushrods to 7.45...STILL making that sound...sounds like its coming from #8. Im about to run the car into a wall. It doesn't tick all the time, just happens whenever it feels like it.

God help me...or maybe LS1tech help me? Perhaps a lifter not pumping up?
Old 09-16-2008, 08:22 PM
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Hi Dunn (Sale Chevrolet).
Going through the same issue. Not gonna wanna hear this but yep it's prolly a lifter since you changed PR's and I assume checked out the rockers. Mine started after an over rev but only does it hot after the oil thins out Which is why I am guessing lifter. The thing I am trying to figure is why?? cause my H/C lifters only have about 4K on them.

Last edited by SOMbitch; 09-16-2008 at 08:31 PM.




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