Broken Valve Spring?

[Jeremyhemphill]

I have an 03 gt. 4.6. Before when I would go WOT. From 1st gear it would rev to 6000 rpms before shifting and it would take off like a bullet. Now I have a loss of power. The engine sounds different like it's diverting air somewhere it shouldn't or something. That's the best way to describe the sound. And if I go WOT it doesn't accel nearly like it should and won't go over 4000 rpms. And the rpms hang there. Tried new MAF. New EGR and new TPS. All to no avail. I'm convinced it's an engine issue due to the way it sounds now. I checked all my shift solenoids with the snap on scan tool at my shop and there is no fault in any of them. No engine codes. And it does miss at high engine speeds. And sometimes at idle. Weird sound coming from intake also. But it's not consistent. Totally random. Need some onsite any help would be great. I'm tearing the valve covers off it a couple days when I have time. I hope i find a weak or broken spring. Seems like I'm getting valve float or one is just stuck. Thanks.


Jeremy

 

[COramprat]

How about the coils? I get random misfire when I get water in the plug wells. I'd pull the coils and plugs 1st and see if there is something amiss there.

 

[Jeremyhemphill]

How about the coils? I get random misfire when I get water in the plug wells. I'd pull the coils and plugs 1st and see if there is something amiss there.

Wouldn't a bad coil throw and engine code though?

 

[Jeremyhemphill]

Wouldn't a bad coil throw and engine code though?

Also it doesn't miss at idle all the time. Only after I try to lay on it will it miss fire at idle. But I did get a cylinder 6 miss fire code along with random miss fire.. p0300 I think it was. And the coil tested good. They were both memory codes. So still no light on. But after clearing the codes the light still doesn't come on. I suppose it's worth a shot to check them all. I need to do plugs anyway. Just wanna make sure there's not a more drastic issue.. thanks for your insight my friend.

 

[COramprat]

Wouldn't a bad coil throw and engine code though?

If it is a dead miss, yes. Mine will get a ramdom miss and not throw a code.