I just recently started hearing louder than normal chatter from under the hood..so i went under there and listened to the valvetrain and it seemed louder than normal (this is even at idle)..the car is at 94K...is there any way possibly the rockers or something could have came loose? how do i know..easy fix if so? what would the symptoms be of a loose or malfunctioninng valvetrain?

Also my last car was an 89 trans am GTA with the L98..at about 90K i heard a rod knocking and sure enough that was it...if an LT1 has a rod knocking what are the symptoms besides hearing it of course?

would it be smart to have a full compression test and fuel pressure test done at this mileage just to be safe? and how much do you think a dealership would charge me? (even though i despise dealerships)

 

it could be just a loose rocker or it could be a collapsed lifter. I would check to see all of your rockers are working first.

 

how do i do that...car runs fine

 

take your valve covers off and just check to se that none of your rockers are really loose. Or you coul just re-adjust them.

 

loose rockers sound like a clacking or ticking sound. I've found that clacking is the rocker arm being loose and ticking is more likely the lifters.

Use a mechanics stethescope or use a large screwdriver against your ear and against the valve cover to isolate the noise. That works pretty good.

If it sounds like a knocking noise, it may be a more serious problem. How's you oil by the way. Do you change it regularly? Is it relatively clean?

Regards,

 

You can tell a rod knock by---- Take it out on a quiet long road. Run at about 40MPH. Get the gas so there is no accelararion or decel (sweet spot)if the noise is there steady then goes away when you accel or decel slightly it may be a rod.If it stays all the time it is not. A rod will not knock under a load--unless it is just before making a window in the block. If you are driving down the interstate like this,if it is a rod, you should be able to make the noise come and go at will with playing with the gas pedal.If it is there all the time and you can't change it with the pedal it probably is something else.

Old school way....

 

I'm having the opposite case... I CAN make the noise come and go at will by playing with the gas pedal... but the noise isn't there at the sweet spot. It's only there under accel (LOAD)... When I'm at the sweet spot, it's nice and quiet, but when I get on it at like 2000rpm in a 6th, you hear it chugging away TICK TICK TICK ....

Is it a rod? or Lifters? or Rockers/Pushrods?

I'm going to lash all the valves today and check the pushrods. I've got big double springs on there, so I'm leaning twards it being a lifter problem...

Just really hope it isn't a bottom end thing.....

 

Turned out that the loud knocking was just over-tight rockers, easily fixed by re-lashing correctly with the engine off.

The other sound, which was kind of a rattle and had me worried (that it might be a bearing), ended up being a shattered rocker arm. Got charged $20 by a dealer for one... wish I had already purchased some Pro Mags

Anyway, car has most of its power back and sounds great again..

Now to fix the leaky rear of the intake manifold....

 

Is this true??? Ive got knocking/ticking noise, that isnt there when the car is cold and doesnt do it under load. Just free reving it, like when the car is in neutral and holding the gas at 2000 RPM or so seems to make it the worst. Its not all that noticable at idle, but its deffinatly there. My oil also seems to get dirty pretty quickly.