ive got a 91 t/a tpi 350 with ticking... ok say its an exhaust leak.. what is the best way to cure this? replace the exhaust manifold gaskets? how loud of ticking is too loud for this engine... if i remember correctly i think i read these engines have roller lifters? Also, what should vac be at idle and where is a good place to check this with a vac gauge? exhaust doesnt sound as good as it did (perhaps my imagineation)... thinking its ignition related unless related to possible exhaust leak.

thanks

 

There ar no gaskets at the heads, just the donut at the head pipe. Could be there. Yes they have roller lifters. You can hook up a vac gage on any vac port on the engine If I remember about 18" on a good well tuned factory engine.

 

i searched and found a post about how injectors can make a ticking noise.. i believe that is what is making noise on my car.. doesnt sound like lifter tap.. could be though the engine has 120k miles on it. i used a pipe to try to hear where the noise was coming from.. and i put my finger on the end of the injector clip and felt the vibration .. seemed to me to be the injectors.. possible? is this a bad thing?

thanks for the input

 

I have had luck finding exhaust leaks by feeling for them when the car is cold. When it is all cooled down start it and start checking with your hand at the manifolds. Must work fast though, doesn't take but about 30 seconds and they are too hot.

 

There are gaskets at the heads- one for every exhaust port except the center 2 ports that are siamesed together and share a single gasket.

There is no gasket between the y-pipe and the maniofld outlet- it's a gasketless flange where the flared end of the y-pipe mates up with a reverse flare sticking out the bottom of the manifold outlet.

Regardless, an exhaust leak will get louder the more load you put on the motor (especially at low RPMs), an injector or rocker tap will stay at the same noise level regardless of load.

 

i dont have gaskets at all on mine, either the head or the manifold to pipe connections, is this not right?

 

Check it again. Cast iron manifolds on chevy small blocks do not have gaskets at the head and the flare at the head pipe is a donut gasket, it can be removed. I just put headers on my Z and that's the way it came from the factory. As far as I know thats the way it has always been.

Headers DO get gaskets Just as you described.