Is this normal? My engine fan on my '05 5.7L is always on. I didn't think anything before but I thought this fan was mainly to cool when the temp got too hot? Not a huge engine guy so just wondering if its normal.

I had a '04 Dakota but didn't notice it.

 

If you are referring to the electric fan on the drivers side. Its not the engine cooling fan. It's for the AC condenser and will run anytime your AC is on. Note, your ac will run in defrost mode also, even if the ac buttom is off. Your engine fan is belt driven and will run all the time.

The dakota is different. The electric fan on the dakota is for auxiliary engine cooling.

 

thx...I'm assuming the electric fan is the large fan (at least 16-20 inch diameter) in fromt of engine behind radiator...

I might have a problem cause the AC is off but fan still runs when truck is on.

 

if the fan is directly bolted to the engine water pump assembly or another pully from the belt it will spin naturaly with the engine from the drag of the bearings. best way to see whats going on it to see if you can stop the fan while the engine is running. if you can when the engine is not hot and you just started up it's ok. but if you cannot stop the fan and the rad is cool then you have a problem

 

NOOOOO! Unless you want to buy a new fan, clutch or have body parts sewn back on, DO NOT try to stop the fan with the engine running.

If the fan truley is the engine fan, you will see a big belt running across a pulley behind the fan. In between the pully and the fan blades will be a clutch pack. With the engine cool and TURNED OFF, try to turn the fan. It will have some resistance, but you should be able to turn the fan without the pulley turning. If you can't, the clutch is bad. It will have some resistance and will normally turn all the time. When the engine is cool, it just won't turn as fast as the engine. When your truck is hot the clutch will engage and the fan will turn at higher RPM. It usually gets a lot noiser when this happens.

 

Then I may be okay. It turns but not at a high RPM. I don't know a lot about engines but I know not to mess with the fan if engine is hot or recently used. Can't type to well with a stump!

I'll try to spin the fan with engine off/cool tonight and see if the pulley doesn't turn.

thx

 

I'm not sure how the hemi fan works but thats what we had to do to make sure the fan clutch was working like it should on hummers since they are activated by hydrolic pressure. we would disconnect the sending unit controller which pressureizes the system and causes the fan clutch to engage.[sm=pcwhack.gif]

 

You'll know when the fan clutch kicks in...if you don't know what it is, you'd could mistake it for a transmission problem as it sounds like an increase in engine RPM associated with a downshift. It makes some noise. I don't know about yours, but for some reason mine locks up 1st thing upon start, then releases after a few hundred yards or so.

The idea behind the clutch is that is does draw more HP at full lock up. If the engine doesn't need the cooling, it free wheels to a varying extent and pulls less air, is quieter and draws less HP

 

Yep, when I start her up I notice it runs for the first 100 yards or so then releases. Just wanted to make sure everything was going right.

Thx

 

I read somewhere that there is a small amount of lubricating fluid inside the clutch pack and that the viscosity change when it's cold is enough to make it run for a little while until the fluid warms up. Not sure if this it true, but it seemed logical to me. Mine usually engages for a minute or so after cold startup.