midge54

Engine has developed a tap and it gets worse as it warms up. I posted a video so you all can hear it. It seems to have started after putting seafoam in the oil and through the carb. It seems to be running on the rich side and I'm not 100% sure that the timing is right

midge54

Anybody??? To me it sounds like the start of a rod bearing knocking. I was only planning on using the 305 in the car until I can finish the lt1 that I plan on putting in but now I won't even drive the car until I figure this out.

ex-x-fire

Pull the valve covers & check for loose rocker arms. Did you put fresh oil in it yet?

midge54

I haven't put fresh oil in it yet and I checked the pass side where the noise seems to be coming from and they are all fine

Damon

I think you have an exhaust leak. The give-away is that it gets louder with engine load (as blip the throttle to rev it). If it was a valve tap it would be constant volume regardless of engine load. They otherwise sound almost identical. And it doesn't sound "low" enough to be a bottom end noise.

midge54

well i can tell you that if you let it run in a garage that it will smoke you clean out, and most of the smoke seems to be coming from the passenger side of the car where the sound is coming from

OLDYELLR

Sounds mechanical, but it's hard to tell from the video. An exhaust manifold leak sounds like mechanical ticking too. Check to see if and exhaust manifold nuts are loose or missing.

midge54

So I changed the oil in the trans am today and although it was really dirty there was no metal in it so I'm pretty sure that along with the passenger manifold leaking leads me to believe that that is the cause of my noise

midge54

so working on the car today i figured i would try and figure out whether this engine is original or not. So first thing to notice is it is running a mechanical fuel pump, so next thing i did was check the head casting numbers and they are 416 heads. i then checked the pad on the passenger front of the engine and the stamps have been scrubbed free. So i tried to find the casting number on the back of the engine but only thing i could find was 5.0 LT SGL stamp on the back so i decided to just crawl under the car and check out the 3 digit number on the block and low and behold it is stamped 878. Researching the number it came up with a 96-up vortec 305 roller engine. So im guessing the block has been machined to run the mechanical fuel pump. I still cant pinpoint where the noise is coming from so i didnt know if this new information would change anything. Ill probably just pull the 305 now since i know for 100% certainty that it is not original