Put Comp Cams and springs in my 04 GT before the blower install. Broke them in and a strange "diesel like" noise was coming from the motor after about 15 minutes almost as if it was the valves themselves. I know, I know it's tough to get any trouble shooting done on line but bare with me 
Looked in the cylinders for contact... none. Inspected plugs, very lean. Took timing cover off, car still in time, redid timing anyway. Put the car back together and started it up... no noise. Great! Ran it for 4 minutes tops. Went on 2 week trip. Started car warmed it up and noise is there again only not as loud. If I disconnect the battery it is not there for a good few minutes then comes on and gets louder. Noise is in both the intake runners and the exhaust manifolds primarily. Sounds just like a diesel motor. Car idles fine then gets pretty rough, shaking on the motor mounts then smooths out again. Hardly ever stalls. Noise is present at idle all the way up to around 2000 when it almost completely goes away or my x pipe is so damn loud I just can't hear any more. I'm pretty sure it goes away. On the street the car is just plain flat all the way to 4000 then it takes off. Shift and it goes flat again. Cams are not too wild, blower grinds, no big deal. Can not find a mechanical fault.
My thought is that the computer my be trying to compensate for the cams. It is leaning it out and pulling timing perhaps causing a detonation type issue which may explain the dieseling. Car runs pretty smooth off idle and I checked timing 3 times... not the problem. It will get a custom tune with the blower but I'm worried I'll have to take the whole thing apart again to fix something before I can add boost. But, having said that, I can't imagaine what it could be if it's not fuel/timing.
Cams are something like 238/242 .550 .550
Comp recommended behive springs
Any thoughts?
Looked in the cylinders for contact... none. Inspected plugs, very lean. Took timing cover off, car still in time, redid timing anyway. Put the car back together and started it up... no noise. Great! Ran it for 4 minutes tops. Went on 2 week trip. Started car warmed it up and noise is there again only not as loud. If I disconnect the battery it is not there for a good few minutes then comes on and gets louder. Noise is in both the intake runners and the exhaust manifolds primarily. Sounds just like a diesel motor. Car idles fine then gets pretty rough, shaking on the motor mounts then smooths out again. Hardly ever stalls. Noise is present at idle all the way up to around 2000 when it almost completely goes away or my x pipe is so damn loud I just can't hear any more. I'm pretty sure it goes away. On the street the car is just plain flat all the way to 4000 then it takes off. Shift and it goes flat again. Cams are not too wild, blower grinds, no big deal. Can not find a mechanical fault.My thought is that the computer my be trying to compensate for the cams. It is leaning it out and pulling timing perhaps causing a detonation type issue which may explain the dieseling. Car runs pretty smooth off idle and I checked timing 3 times... not the problem. It will get a custom tune with the blower but I'm worried I'll have to take the whole thing apart again to fix something before I can add boost. But, having said that, I can't imagaine what it could be if it's not fuel/timing.
Cams are something like 238/242 .550 .550
Comp recommended behive springs
Any thoughts?
