Low power, low boost, high EGTs
I've been on a slow quest to improve reliability and replace/upgrade much of my 2005 E350 6.0 (165k).
I've been starting with fuel delivery and electronics; working my way through Alternator, FICM, batteries, etc. Seem to have sorted rough start, improved cold performance and other common issues tied to that.
Most other 'common 6.0' issues have been replaced/repaired/or ruled out.
These days, my challenge is low power (relative to this van's historical), high EGT's (8500-9000 at cruise, even low grade gets me to 10500 quickly), and low boost (6lbs or less). Now... I don't entirely trust my boost gauge and will verify it's reading with a scan tool soon.
I suspected turbo or intake leak and decided to put new turbo and intake elbows on. It was time to replace turbo anyway.
I did have a mechanic do some troubleshooting (pretty familiar with 6.0) and he checked Exhaust Back Pressure, which appeared to be quite high at 50psi. His theory is plugged catalytic convertor. I have no codes. This is interesting to me because I had not thought of this (would have expected a code)... and it also might explain where I get almost zero audible turbo whine--and I remember having it on this van. Plugged Cat might explain high EGT, low boost... and therefore low power, right?
So... two questions:
- this sound like a viable theory? If yes, who do you like to buy new Cats from? Should I go ahead and do Cat-back exhaust at the same time?
- mechanic also found a decent hole in the Downpipe that I somehow missed? Where can I source a replacement downpipe for the Van? I can't seem to find anywhere. Do you have to go used?
Thanks all, you are an unbelievable resource!