I'll try to keep it brief.
2001 Edge, 3.0 manual with 87k. I've searched the forums and found some similar issues but not exactly. . .
CEL on, P0401. Pretty sure dpfe sensor again (replaced about 1 yr ago). I just had timing cover gasket replaced to correct coolant leak, replaced water pump since it was down.
I seafoamed it prior to gasket/water pump replacement. It immediately developed a squeal I've not heard before. Not sure they're related, just trying to give as much info as possible. I thought it might be the water pump on its way out, but no.
Oddly, the squeal/whistle only happens when the engine warms up and only below 2k rpm. With stethoscope, noise almost sounds like its in the egr system. I read some threads about cam synchro last night but haven't been able to check this area yet. Since it is more costly, I'm figuring that will be the problem.
Thoughts?

Thanks in advance!!

 

Weeeeeeell, cam synchro it is. Now that I know what I'm hearing, I have a feeling it's been occasionally chirping for some time. We'll find out soon.