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