spun bearing (maybe)

[DIESEL5]

i did a head job on my 93' 6.5 about a month ago and after getting some small bugs worked out the truck was running great for a couple of weeks so i took it up for an E-check and it passed but on the way home I lost the temp gage completely and only reading 10volts on the alt gauge and suddenly i lost power as if it went into a limp mode the truck is hard starting when the motor is warm and the idle is very rough cold or warm I heard a rattle somewhere in the top end but cant pinpoint it and its intermittant I wondering if maybe it spun a crank bearing it has 165000 on the engine the oil doesn't smell burnt though. any ideas or suggestions on where to start.

[a5150nut]

Have you checked ALL ground connections? I did some work on my 94 a while back and my volt gage started bouncing around and dropping. I left the right side battery ground loose. Tightened it up and everything is now fine. It even got fuel prices bellow $3.00! :D

[JohnC]

The good news is I doubt seriously if you spun a bearing. On the other hand, I don't have a clue what could be wrong. I guess I'd look for an electrical problem and maybe a valve train (rocker arm?) problem.

[ercaduceus]

Bad injector or air in the fuel system could be the knocking sound. Not sure how that would affect electrics. I agree with a5150nut, check the battery and engine grounds first.

[DIESEL5]

i Checked all the electrics replaced the alt and the temp sending unit the are working fine now but still same problem, the engine gets up to 210 degrees quickly and the idle is still rough and when its upto temp it gets real sluggish and the oil pressure starts dropping I dont think its a fuel problem at all

[DIESEL5]

would a loose rocker arm or broken nylon retainer tend to cause a problem like this or maybe collapsed lifter?

[DIESEL5]

when i did the head job iput a new injector pump and eight new injectors in it oh and a new fuel pump the truck has been running like new for about three weeks until this problem