started truck up one morning this past week and check engine light came on........................ if it is idling doesnt make noise but when i press the fuel pedal it kinda makes this weird noise and its coming from the fan area...................if i turn the fan switch on, the check engine light goes off???? any ideas before i take it to detroit diesel?? i took it to TA, flash codes were 46(ecm) and 62(aux power)..i may need new batteries, mind you both of those codes were already there b4 this problem

 

and my fan starts automatically when i start truck, it always seems to be running, regardless if its hot or cold

 

this may be obvious, but have you checked the water level?

 

yeah coolant level is good........... its at normal level, im gonna take it to detroit diesel next week and just wanted to see if maybe some1 knew........ someone told me the clutch bearing or something????

 

fan clutch.

 

I don't know if Freightliner uses Horton fan clutches. You have an EGR engine, right? Find out if they use Horton and if so get to the dealer before anything else :shock:

 

no egr engine, this is on 2000 freightliner, fan clutch expensive????? that would make sense if it was fan clutch, is that expensive

 

It's hard to tell, w/o knowing what type, and how you want to deal with it.
But I'd say around $5-600... :roll:

 

Is it an air leaking sound(clutch worn out) or a squeeling bearing sound(fan hub). They're separate pieces, at least on my truck they were.

Could just be your belt is loose.

In the morning, when you fire it up, the alternator load will be highest. It's just enough that it will only slip during the morning.

Fire it up for 20 seconds, turn it off, feel the pulley. If it's warm where the belt meets the pulley, it's slipping.

The reason it goes off when you hit the fan switch is because it puts a load on the belt, tightening against the pulley.

Just an idear.

 

Rev up the engine at night and see if the fan clutch is throwing sparks. Looks really cool at night lol :lol: