another E-fan thread

[tybardy]

i am going to try and pull a set of E-fans from an 05-06 model from a junk yard ASAP... i need to know what all I need to make sure i pull with them... also, once i pull the fans, will i need to buy anything else?

also, when removing the belt driven fan, is pulling the blade off all that is needed? or does something need to be disengaged

[Sepiroth]

Get the fans, wire harness and related wiring.

You're going to need to get a fan clutch removal tool to remove the fan from your truck.

Also before you wire up your fans, it would be a good idea to have a BB tune to activate the appropriate pin out on your ECM.

[tybardy]

fan clutch removal tool ey... how much would one of these run me?

I have a BB tune, am i going to need to have him ship me an all new PCM? maybe i am going to need to direct a few questions his way.

[Sepiroth]

IIRC the fan removal tool you can rent from say a place like autozone

[tybardy]

ok... now lets play the swap game for a second. I have a friend who has a 2005 chevy work truck w/ the 4.8L. He has agreed to let me swap my fan over to his and his to mine for $100...

I am going to take him up on this offer assuming it wont cost me anything other then the $100. here are my questions

Is there a problem going from e-fan to standard belt driven fan? What is required to go from having the e-fans to having belt driven fan?

[Sepiroth]

Not so much a problem as far as I can see. There may be a service engine light on your part, if the ECM sends a command to turn on the fans and then the ECM doesnt get confirmation. However, I do not think our ECM's are that smart.

The only other thing you may notice is a small maybe even barely noticeable decrease in H.P. and maybe a little more fuel consumption. As it does take energy to turn the fan.

A little bit of insurance, if you're going this route, you might want to replace the fan clutch as that would be the most oppurtune time to do so.

[JennaBear]

E-fans is a very good mod for these trucks that didn't have them stock. You will need the wiring harness for them, if you can't find one, we sell them. Another thing to consider, is your alternator. These older trucks without the fans from factory had a lower amp alternator, to compensate for that, you may want to consider the overdrive pulley.

Double check with Justin on your tune, but I am 99.9% positive that your PINs are probably already turned on. He usually does this on all his tunes to save customers the hassle down the road.

[tybardy]

E-fans is a very good mod for these trucks that didn't have them stock. You will need the wiring harness for them, if you can't find one, we sell them. Another thing to consider, is your alternator. These older trucks without the fans from factory had a lower amp alternator, to compensate for that, you may want to consider the overdrive pulley.

Double check with Justin on your tune, but I am 99.9% positive that your PINs are probably already turned on. He usually does this on all his tunes to save customers the hassle down the road.


thats AWSOME, i was really not looking forward to having to wait for another new PCM so i could run my e-fans. I can never say enough good things about Black Bear...

anyways, regarding the alternator. I am really doing this mod for the MPG gain as i cant see it giving me much more then a couple of HP. However, when you say consider the overdrive pulley, will that just add the same "pull" to the motor that i am trying to lose by doing this mod? And if that is te case, why is this still a good mod?

[sschrader]

I just did the e fans on mine (02) about 2 weeks ago. I have the older PCM so I went JK's route, I bought a e fan thermostat and wired that in. Works perfect. It turns on right when it should, and will come on instantly if you turn the AC on. Your newer model you won't have to worry about the aftermarket thermostat. It's so much quieter, I wish I would have done it earlier. As far as the power, I didn't really notice anything, like I said, just seems quieter in the truck. Plus there is so much more room in the engine bay.

I have yet to check my MPG. When the stereo (1000W amp and 2 - 12's) and e fans are on, the volt gauge drops a little, but never under 14v.

Hurry up and do it!

[BOSS]

I just did the e fans on mine (02) about 2 weeks ago. I have the older PCM so I went JK's route, I bought a e fan thermostat and wired that in. Works perfect. It turns on right when it should, and will come on instantly if you turn the AC on. Your newer model you won't have to worry about the aftermarket thermostat.

So the thermostat is different for the 2002 model?? I'm confused now...I thought by using the harness and the PCM efan switched on, you don't ahve to do shi!t else. It seemed JKs way was to ensure when the AC clutch kicked in, the efan would also.

?
BOSS

[sschrader]

BOSS,

The way I understood it was, 03+ trucks were able to have the PCM switched to control the fans. I have a 02. The thermostat (for the fans) I purchased was just a general one, for any e fan set up. But you can set it to come on at different temps.

[tybardy]

if there isnt any change in power or MPG's, then what is the point to doing this mod?

[sschrader]

I am sure there is in MPG, I just have not checked mine yet. The old clutch fan is heavy. Freezing cold AC while sitting in traffic is worth it if that's the only thing it accomplishes.

That and its so much quieter. Doesn't sound like a big deal, it made a difference for me though. It's almost like using dynamat, if that makes sense.

[Max]

I have a set of the 05+ fans sitting in my basement awaiting a harness, should net some decent power and a solid 1mpg maybe more. I just wanted to clear out the engine bay, never like the clutch fans either. If you can't find any at the junkyards just buy the ones off ebay, $225 isn't bad for new parts.

[tybardy]

yea, i am certain i can find one.... i have a buddy who is willing to swap my clutch fan for his e-fans since its out of his work truck and he doesnt pay for gas... i am trying to work out the legistics of that though, not sure on the whole swapping my fan back into his ride and how thats going to work

[BOSS]

BOSS,

The way I understood it was, 03+ trucks were able to have the PCM switched to control the fans. I have a 02. The thermostat (for the fans) I purchased was just a general one, for any e fan set up. But you can set it to come on at different temps.

I thought the 02 models could have the pcm changed to control the fans? Can someone confirm this? Jenna?


BOSS

[BOSS]

Ttt


boss

---------- Post added at 08:59 PM ---------- Previous post was at 08:56 PM ----------

However, when you say consider the overdrive pulley, will that just add the same "pull" to the motor that i am trying to lose by doing this mod? And if that is te case, why is this still a good mod?

Anybody know the answer to this?

I'm still researchign and trying to find out if 2002 PCM and thermo will operate the efans.

BOSS

[JennaBear]

thats AWSOME, i was really not looking forward to having to wait for another new PCM so i could run my e-fans. I can never say enough good things about Black Bear...

anyways, regarding the alternator. I am really doing this mod for the MPG gain as i cant see it giving me much more then a couple of HP. However, when you say consider the overdrive pulley, will that just add the same "pull" to the motor that i am trying to lose by doing this mod? And if that is te case, why is this still a good mod?
The pulley helps with your idle amperage since you have an 105amp alternator. There is nothing to lose with the pulley.

So the thermostat is different for the 2002 model?? I'm confused now...I thought by using the harness and the PCM efan switched on, you don't ahve to do shi!t else. It seemed JKs way was to ensure when the AC clutch kicked in, the efan would also.

?
BOSS

The 99+ models can control the e-fans, you just have to have the PINs turned on. What sschrader may be thinking about is the dual pin set up. The PCM only had the capability for the dual pin setup in the 03+ models. The 2 PINs allow for dual speed via the PCM.

if there isnt any change in power or MPG's, then what is the point to doing this mod?
You should notice a change in both, but don't expect anything too drastic.

[tybardy]

yea i wasnt expecting anything drastic... i was hoping for maybe 1 mpg...

[OKLAGMCRUISER]

i am going to try and pull a set of E-fans from an 05-06 model from a junk yard ASAP... i need to know what all I need to make sure i pull with them... also, once i pull the fans, will i need to buy anything else?

also, when removing the belt driven fan, is pulling the blade off all that is needed? or does something need to be disengaged

if it's not too late pull the radiator too as it's the larger radiator in the 05+ and the fans will bolt right up to it. you don't need a special tool to pull the clutch fan. i used a large pipe wrench and a hammer to whack the handle of the wrench to loosen the fan on my 99. used the same method to put it back on before i sold the truck and removed the fans.

[tybardy]

if it's not too late pull the radiator too as it's the larger radiator in the 05+ and the fans will bolt right up to it. you don't need a special tool to pull the clutch fan. i used a large pipe wrench and a hammer to whack the handle of the wrench to loosen the fan on my 99. used the same method to put it back on before i sold the truck and removed the fans.

goood to know mang... yea i still have not got around to doing this, i have been in super lazy mode lately! i was unaware that the 05-06 model had a bigger Rad though...

[JennaBear]

Ty- you already have the larger radiator due to the Z71 package.

[OKLAGMCRUISER]

Ty- you already have the larger radiator due to the Z71 package.

thank you jenna...i guess i didn't know that either...and his sig is blocked at work...lol.

[tybardy]

also good to know... i sure am glad i got the Z71... it would be PERFECT if it wasnt for the nasty grey trim!

[Grocery Getter]

if it's not too late pull the radiator too as it's the larger radiator in the 05+ and the fans will bolt right up to it. you don't need a special tool to pull the clutch fan. i used a large pipe wrench and a hammer to whack the handle of the wrench to loosen the fan on my 99. used the same method to put it back on before i sold the truck and removed the fans.

Hmmm. Gonna pick up my e-fan assembly soon, did not know that about the radiator. I have an 04' LT not Z71 how big is the "bigger" radiator so I can measure mine and if I do, which I probably do, have the smaller radiator will the assembly still work/fit?

[OKLAGMCRUISER]

Hmmm. Gonna pick up my e-fan assembly soon, did not know that about the radiator. I have an 04' LT not Z71 how big is the "bigger" radiator so I can measure mine and if I do, which I probably do, have the smaller radiator will the assembly still work/fit?

i don't remember exactly the 2 different sizes...memory serves me one is 28" and the other is 34". When I did my efans I used ls1 fans so I'm not exactly sure if the 05-06 fans will work directly over the smaller rad or not. Hopefully someone that has done this exact mod can chime in. You might check with someone at gmfs or pt.net as i know alot of the truck guys have done this mod with ls1 or oem fans.

Pat

[Grocery Getter]

Ty- you already have the larger radiator due to the Z71 package.

Jenna,

What are us smaller radiators fellers to do? Will the OEM 05+ assembly still fit?

[JennaBear]

You will know if you have the larger radiator, if you measure from bolt to bolt and it equals ~38". If you have the smaller radiator, I would recommend the LS1 fans like Pat mentioned.

[Grocery Getter]

You will know if you have the larger radiator, if you measure from bolt to bolt and it equals ~38". If you have the smaller radiator, I would recommend the LS1 fans like Pat mentioned.

Ok, if u mean bolt to bolt on the back side of the radiator at the top by the hose then Im
all good at 38"....

[JennaBear]

Yep, the Z71s and the ones with the towing package have the larger radiator.

[dec322]

So the thermostat is different for the 2002 model?? I'm confused now...I thought by using the harness and the PCM efan switched on, you don't ahve to do shi!t else. It seemed JKs way was to ensure when the AC clutch kicked in, the efan would also.

?
BOSS

I didn't feel like this question was directly addressed so I will say something to it. Initially I was confused with the talk of the new "thermostat" because I was thinking of the coolant thermostat. These are two different t-stats.

The one used for the e-fan setup goes between the fins of the radiator. It sends the temps to the fan controller and the controller turns the fans on at the set temperature.

You still retain the stock t-stat for the coolant system.

I like this method best because it would be cheaper for me. JK did his for under $150 (I think).

Now, if I had the BB tune like the OP then I would go with the 05-up fans. Not everyone can live the yukon/tahoe mod dreams.