Just bought a 78 z28 Camero and it has an EFE (Early Fuel Emissions) system that helps to warm the vehicle up during start up. I think there is a vaulve that may be loose that's part of this system, cause everytime I step on the gas, I hear a ticking noise coming from that area (the system is connected to the left side exhaust manifold). The more I give it gas the faster the ticking noise (but not louder). If the car is in park and I step on the gas, I don't hear the noise. Is this a loose vaulve, or did a spring pop or is the ticking noise something else alltogehter? If anybody knows anything about this EFE system, please let me in.

I'm not sure about a Camero, but on the CamAros the EFE (Early Fuel Evaporation) valve is on the right side. Your noise does sound like an exhaust leak, but if it's on the left (drivers side) than it will not be the EFE.

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Dave

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Sort of like when someone mentioned the words "air shocks" around Lowend! LMAO!! http://www.nastyz28.com/ubb/biggrin.gif

Putting that aside, the shaft inside the unit can get loose and "rattly." The valve can't really leak that I've ever seen as it is "sandwiched" between the exh manifold and y-pipe. No gaskets to blow out. Assuming the y-pipe is installed correctly it should never leak.

It sure sounds like an exhaust leak to me, although you say the volume of the tick doesn't increase with load.

Are we talking about the "flapper" heat-riser valve that is usually on one side's exhaust manifolds end between the exhaust pipe and manifold so that when it is closed, it forces the exhaust to go up under the intake manifold to help heat it???

pdq67

EFE flapper was on the end of the passenger-side exhaust manifold on every 2nd gen I've ever seen.

EFE must DIE DIE DIE! Whew, I feel better. http://www.nastyz28.com/ubb/smile.gif What a ridiculous idea for warming an engine. "Hey, Cletis, I bet if we put a valve here, it'll get us REAL hot like, and won't bother the HP at all..." But I digress...

Does your car also have an AIR pump? If so, check the AIR pipe that goes into the manifold for holes. If there are any, that's where the ticking noise is likely coming from. They are known to rust.