I posted this in the LT1 section but this one gets a lot more traffic so i am hoping some of you guys can offer me some insight. thanks!




my lt1 amigos, I need some help.

on my way home from the track, i was driving on the highway and i began to hear this high pitched wail come from the engine compartment(it sounded almost like a turbo / sc spooling). it was just slight at first, but eventually got to the point where it would start screaming under any kind of load and would lose a lot of power. then i popped the hood and noticed that my drivers side exhaust manifold was glowing bright red! i then got the car towed home. i havent had the chance to diagnose it myself, but i have heard from a few that it could be a rocker. what do you guys think?

and if it is a rocker, would it be possible/good to upgrade to 1.6rrs on an otherwise stock valve train? and if so could you suggest some?

thanks big time guys!
-Tony

 

I base this on absolutely nothing, but a failed rocker wouldn't do that. That sounds like that side was running incredibly lean, like a bad injector or something. If your manifold really got that hot I would be very concerned.

 

yeah i have based the whole blown rocker thing on what someone said to me but they only have slight experience in this area, anyone else care to chime in?

 

Just like Another_User said, a glowing exhaust manifold usually means a VERY lean condition. I don't see how a broken/failed rocker arm could cause such a lean condition. I have only seen glowing headers on a couple occations and they have both been carburated applications when the car was idling with a bad air/fuel mixture.

I would think it would have something to do with a fuel injector or fuel injectors on that bank of the motor causing it to run so lean. Even if a rocker arm were to fail/break, and an intake valve was to stay closed, it would have the opposite effect and run fat.

 

the one time my 94 z28 had glowing manifolds, the cat collapsed at the track. no way to get the exhaust out. only one side glowing could mean too much fuel in the exhaust.

 

Hey Transamula,I don"t think its a rockerarm,Before you do any mechanical work I would do a diagnostic check maybe it will pop up a code to show what might be wrong. Could be an injector or plugged up cat like was mentioned before. If you don"t find anything there I would do a compression test on each cylinder,if you got it that hot may have burned a piston(hope not)doing this would show which cylinder has a problem.If you find a low test on a certain piston then pull valvecover to see if something is wrong on the rockerarm,pushrod,spring,etc.
IF you decide to get new rockerarms go to 1.6 ratio but get some stronger valvesprings!!Comp makes a Magnum that will fit under your centerbolt valvecovers,Crane makes a narrowbody rocker that will fit too.You may have to do some surgery on the valvecovers too!
Hope its nothing too major!!!BTW cool sig name

 

That's easy enough to check. If the cat is bad it would be glowing cherry red too. In fact, it would be the first thing to start glowing.

 

thank you guys so much, i'm still cutting my teeth on these f-bodies, and basically cars in general. I'm going to try to get this sorted out and if it is just a cat then hopefully it will be back on the road in no time. it figures that this would happen the same day that my QTEC and my jet hots arrive!