Engine Miss, Shuddering Under Load, Low Power, Low MPG

[tad240]

2003 Excursion Diesel running rough. Missing at all times. Shuddering badly under load. Pulling a trailer and it was constantly downshifting to maintain speed. Fuel mileage is down to 8-9mpg with a 1 horse in a bumper pull.

Started getting worse a few months ago. At 1st, when starting as a cold engine it would run OK. But if you shut it off and restart it while still warm, it would run rough.

Now it always runs rough, cold or warm. Doesn't matter.

160K miles. No history of engine work at all. Just regular maintenance. New fuel filters, fresh 5W-40 rotella, 2 bottles of the injector stiction oil made no difference. No check engine light. Seems to be getting worse.

I think its injectors but not sure. Any ideas / suggestions?

[Ryanbaker83]

Buy Auto Enginuity and check for soft codes. My 05 has never had a check engine light but has had plenty of codes. Sounds like injectors, but without more info it's really a guessing game at this point. Could be any number of seals or sensors. Also watch your hpop pressure. Mine has done the same thing and turned out my IPR valve went bad. So like I said really need more info.