Hey everyone, I've recently got my car back from the mechanic with a fresh 68 400 Motor thrown into my 1967 Firebird. I've got a pretty heavy cam and all brand new innards. The only things from the last engine that were able to be saved were the heads and headers. I'm driving it softly for the first 500 miles until I get in there and change the oil and I've barely taken it out for anything since I still need to get the timing and carburetor dialed in.
Right now, it's dieseling because of the timing, but I've got an appointment with my new mechanic to get it all adjusted alongside my oil change. I've also got a temperature issue but it's looking like just a wiring problem.
Besides that, I'm hearing a noise that sounds like paper flapping in the wind when the car is in drive. I don't hear it when idling but as I take my car out of the parking lot, the loud cam sound slowly transforms into a slight paper flap that remains consistent and grows faster and faster when I reach higher RPMs. When I let off the gas and slow down to a crawl it disappears and all I hear is the cam. Could this just be the cam making normal noises when driving? Or is this a serious issue? I'm going to get this all checked out next week but I want to be prepared in case it's a big deal. I just got this motor built and installed last week, so I can't imagine it's already showing problems.
Congrats on getting the car back together. I am drawing a blank on the noise you are describing, hopefully someone will come along with a suggestion or two for you. The noise does sound as if it is coming from the engine compartment though? Cal
Yep. My buddy does a lot of his own work on his own Mustang and he thinks it's lifter tick. We're thinking it might be just a symptom of it needing to be broken in still.
He decided it might be that when he put his ear to my heads and heard the same noise, but faintly.
Did you put new adjustable rockers on? I've seen where the gasket is too thin and the rockers are actually Making contact with the valve cover... Easy enough to fix, think Ames sells bigger (taller) gaskets to give you a bit more room... The issues is easy enough to diagnose, pull the cover and see if there is any evidence of contact.
Sounds like goose might be on to something. Or maybe a gasket leak. Intake or exhaust. Doesn't sound like anything tragic unless it's effecting the way it's running.
My mechanic said it was just an exhaust leak. He drives a 69 and got mine sounding a lot like his before releasing it to me. I'm going to have get the exhaust welded because it's only clamped right now. It's an aftermarket system so I guess they just went the easy route on it. Hopefully that fixes it.
it's not a leak at the head? i tried the copper gaskets at one point on my 400 and they were leaking piles of junk... you might save your pocket with the mechanic and put them in yourself usually about a 30-45 min job. Just remember that the slip into place and you don't need to remove all the bolts... good luck and thanks for the update.
