[wink2873]

ok, so everyone knows the "roar" daks/durs get sometimes when you first start it up and drive off. Well, now mine does it like ALL THE TIME. If im lucky, it'll stop after like 10 minutes. Its not like its getting too hot or anything. Also, when I have the heater on, there is some sort of clutch type thing clicking on and off like all the time. Is this the same as the fan clutch? I dont know.. Im confused. If I have to replace this, how expensive is it and how hard is it to do?

 

[hskrRT]

ok, so everyone knows the "roar" daks/durs get sometimes when you first start it up and drive off. Well, now mine does it like ALL THE TIME. If im lucky, it'll stop after like 10 minutes. Its not like its getting too hot or anything. Also, when I have the heater on, there is some sort of clutch type thing clicking on and off like all the time. Is this the same as the fan clutch? I dont know.. Im confused. If I have to replace this, how expensive is it and how hard is it to do?

The clutch kicking on and off is your A/C clutch as the A/C cycles with the defrost on to remove the humidity from the air to aid in keeping the windows defogged.

 

[wink2873]

The clutch kicking on and off is your A/C clutch as the A/C cycles with the defrost on to remove the humidity from the air to aid in keeping the windows defogged.

thats interesting. Is it supposed to kick on and off like every 5 seconds? What about the fan clutch? Does it need fixed? I know it shouldnt be on as long as it is because it never was before.

 

[hskrRT]

Yes at idle it will cycle like that. As for the fan clutch, could probably use replaced, but if it's cold out, it is a viscious fan clutch using fluid and cold fluid needs to warm up to spin easier.

 

[02sxtkota]

could just ditch the clutch fan, had mine off for a year and e-fan kicks on and cools it even in traffic on 90+ days.

 

[Little Blue Guy]

If your AC is clicking on and off every 5 seconds...I bet you need to service the AC system. Sounds like you need a new fan clutch....mine roars also, but only for 1/4 mile after start up

 

[wink2873]

i would be interested in getting rid in the clutch fan. How hard is this to do? I didnt even know I had an electric fan on my 3.9.

 

[Little Blue Guy]

If you have an electric fan on your truck, then unscrew the clutch fan and yer done.

If you don't have electric fan, you cannot discard the clutch fan, it must remain on to cool radiator & AC condenser

 

[modain]

If your AC is clicking on and off every 5 seconds...I bet you need to service the AC system.

A/C cycling on/off every five seconds is usually due to not having enough refrigerant in the system. My daughter's Jeep Cherokee did this and it drove me crazy (because the eFan cycled with the A/C clutch). Once I filled the system with enough refrigerant to keep the low pressure from falling below the cutoff point within seconds it worked like a charm.

[I am not an A/C expert, but this is what I have come to understand.] In case you (or anyone) would like to know how it is supposed to work... The system has a volume of refrigerant gas in it. The compressor kicks on, sucks the gas through the input port, compresses it and sends it out the high pressure side. When the pressure in the low side falls below the bottom threshold (can't remember exact value: 20psi, 40psi?) the compressor kicks off. If you don't have enough gas in the system the low side pressure will fall below the limit very soon after the compressor kicks on. There should be enough gas in the system to keep the compressor from pulling the low side pressure below the threshold for at least 10-15 seconds.

The high side works in the converse: the compressor cutoff is forced when the compressed gas in the high side meets or exceeds the high pressure threshold. This can happen too quickly if there is too much gas in the system.

If your truck is old and the A/C has never been serviced your issue is most likely due to low gas volume from it leaking out over time, not too much gas - that comes from overfilling.

 

[wink2873]

A/C cycling on/off every five seconds is usually due to not having enough refrigerant in the system. My daughter's Jeep Cherokee did this and it drove me crazy (because the eFan cycled with the A/C clutch). Once I filled the system with enough refrigerant to keep the low pressure from falling below the cutoff point within seconds it worked like a charm.

[I am not an A/C expert, but this is what I have come to understand.] In case you (or anyone) would like to know how it is supposed to work... The system has a volume of refrigerant gas in it. The compressor kicks on, sucks the gas through the input port, compresses it and sends it out the high pressure side. When the pressure in the low side falls below the bottom threshold (can't remember exact value: 20psi, 40psi?) the compressor kicks off. If you don't have enough gas in the system the low side pressure will fall below the limit very soon after the compressor kicks on. There should be enough gas in the system to keep the compressor from pulling the low side pressure below the threshold for at least 10-15 seconds.

The high side works in the converse: the compressor cutoff is forced when the compressed gas in the high side meets or exceeds the high pressure threshold. This can happen too quickly if there is too much gas in the system.

If your truck is old and the A/C has never been serviced your issue is most likely due to low gas volume from it leaking out over time, not too much gas - that comes from overfilling.

thanks for the info, sounds like I need to get the AC serviced (its never been serviced before). I looked under the hood today and the AC compressor is definately kicking on and off every 5 seconds.

Also, it looks as though my truck DOES have a small electric fan on the backside of the radiator. I never knew this was there before... It looks to be probably about a 16 inch single fan. Does this run all the time or what? If it doesnt run all the time... how does it know when to turn on??? If I take off the clutch fan, would this be enough to cool my truck? I live in northern ohio.. so its cold in the winter and sometimes 90-100 in the summer. I do have a 180 T-stat in my truck and Ive never seen it even get up to the middle of the water temp guage before... even on the hottest of days. AND... if I took off my clutch fan, could I take offf the stupid fan shroud? Or at least cut it down some?

 

[modain]

Also, it looks as though my truck DOES have a small electric fan on the backside of the radiator. I never knew this was there before... It looks to be probably about a 16 inch single fan. Does this run all the time or what? If it doesnt run all the time... how does it know when to turn on??? If I take off the clutch fan, would this be enough to cool my truck? I live in northern ohio.. so its cold in the winter and sometimes 90-100 in the summer. I do have a 180 T-stat in my truck and Ive never seen it even get up to the middle of the water temp guage before... even on the hottest of days. AND... if I took off my clutch fan, could I take offf the stupid fan shroud? Or at least cut it down some?

The eFan is activated when the A/C or defroster is turned on. It will run continuously while the snowflake is glowing, regardless of the A/C clutch state. It will also kick on at 210* water temperature if the A/C is off.

Without the clutch fan in your truck might stay cool in the heat you mention. A lot of folks around here run with just the factory eFan and they seem to be OK. Search, and ye shall find... It's not worth the risk though if you tow.

Do *not* take off the fan shroud. You won't get proper airflow through the radiator without one. You might be able to find or fabricate one more to your liking, but you need a proper one or you are asking for trouble.

 

[KotaChuk678]

Yeah mine (clutch fan) had been off for a year and a half with no problem at all, I removed the upper shroud portion too. It looked good and ran fantastic without it.

I even invested in a Flex-a-lite temperature control to monitor it (e-fan) coming on at 190* instead of the 210* degree temp.

Back in November I purchased a new garden tractor and and through it on the back and we stopped to shop on the way home (I stayed with the truck) and saw the inside guage climb way above normal.

Through a P1281 code right after that and had to replace the thermostat (180*)

It hasn't been working properly since then, not sure if it's the e-fan burned out or the temp control yet! It won't work with the A/C snowflake either.

I've re-installed my fan clutch after being caught in an ice storm on my daily commute where the traffic was at a standstill and the water temp guage climbed almost into the overheat zone.

So it is very do-able but requires a lot of monitoring and not quite sure if the good outway's the bad I mean if your girl/ wife/ friend was using it they might not notice what's going on in a predicament as such.

That's what is on my mind now :huh:

 

[6shooter]

just pull the fan off. all you gotta do is hold the water pump pulley somehow and put a wrench on the big nut behind the clutch housing and unscrew it. if need be, you can always bypass the factory e-fan wiring later and put in an adjustable thermostat to kick on at a lower preset engine temp if you end up overheating in the summer.

 

[wink2873]

The eFan is activated when the A/C or defroster is turned on. It will run continuously while the snowflake is glowing, regardless of the A/C clutch state. It will also kick on at 210* water temperature if the A/C is off.

Without the clutch fan in your truck might stay cool in the heat you mention. A lot of folks around here run with just the factory eFan and they seem to be OK. Search, and ye shall find... It's not worth the risk though if you tow.

Do *not* take off the fan shroud. You won't get proper airflow through the radiator without one. You might be able to find or fabricate one more to your liking, but you need a proper one or you are asking for trouble.

aaaahhhhhhh... I understand it now. I think for now I'll just take it off, and if it starts running warm in the summer I'll try to come up with a way to maybe just wire up a switch to turn on the efan from inside the cab or something. Or I'll just buy a new fan clutch and put it back on if worse comes to worse.

 

[02sxtkota]

just pull the fan off. all you gotta do is hold the water pump pulley somehow and put a wrench on the big nut behind the clutch housing and unscrew it. if need be, you can always bypass the factory e-fan wiring later and put in an adjustable thermostat to kick on at a lower preset engine temp if you end up overheating in the summer.

buy a set of those rubber plier things where its a rubber piece that looks like ur fan belt, was real cheap at sears, has a plastic handle and worked great didnt move an inch.

 

[hskrRT]

buy a set of those rubber plier things where its a rubber piece that looks like ur fan belt, was real cheap at sears, has a plastic handle and worked great didnt move an inch.

Those are called strap wrenches.

 

[6shooter]

Those are called strap wrenches.

"rubber plier things" are much more self explanatory, tho :funny:

 

[ThisOldDak]

I have heard of quite a few people running with only the stock e-fan. and I can't imagine all of them are farther north than you are.

Since the e-fan will not be on all the time sapping power you will probably notice some slight perfromance/responsiveness increases as well, especialy if the fan clutch is (almost?) ciesed.

 

[wink2873]

well, most likely Im gonna be taking the clutch fan off tomorrow. Being winter time, I dont forsee any overheating problems. When it gets hot out again if it starts to overheat I'll just replace the clutch and put the fan back on. If I think about it, I'll take some pics and post them up here.

 

[wink2873]

finally got the bastard off. I broke 2 rubber strap wrenches trying. Then I figured out if I kept the belt on, I could move in the tensioner a little just enough to wedge a pry bar in there and that way the belt had more tension and it wouldnt turn the pulley... what a pita. Its running at the same temp it always did without the fan so Im not worried about it.