View Full Version : 05 LLY clutch fan
REDTRUCK05
06-12-2006, 22:26
My clutch fan ran Mothers day weekend for 17 miles. I was pulling at 60-70 mph. Is there a solution?
DmaxMaverick
06-13-2006, 11:05
My clutch fan ran Mothers day weekend for 17 miles. I was pulling at 60-70 mph. Is there a solution?
Earplugs...
Contact this guy, beekiller@cox.net and tell him your problem. He has a real nice fix for it. It will never be 100% gone but it will reduce the amount your fan runs by about 50% - 80%.
Dan
Contact this guy, beekiller@cox.net and tell him your problem. He has a real nice fix for it. It will never be 100% gone but it will reduce the amount your fan runs by about 50% - 80%.
Dan
They're pretty hip to people cheerleading here... ;)
Here's my take on running hot:
http://www.kennedydiesel.com/docs/LLY_Running_Hot.pdf
Now since I've written this, a couple of other tricks have emerged.
One is an Engine Oil Cooler offered by a guy going by "killerbee." There are only a couple of these out to the public and little testing has been done with BIG loads.
The other is a "pony" (secondary) radiator offered by a guy going by "TXChristopher." There are supposed to be a bit over a dozen of these out to the public with good results so far. There has also been limited testing with BIG loads, but Rick Lance has been towing heavy with good results. He still got hot, but now seems to have a failing fan clutch. He can comment further.
The thing I'd like to see is for someone to take my splash guard "prop down" mod and add a shroud between the OE splash pan and the radiator core support. The idea is to create a concentrated low pressure area for the air to flow to under the truck...
REDTRUCK05
06-18-2006, 20:51
Earplugs...
Just trying to get constructive input.
REDTRUCK05
06-18-2006, 20:59
They're pretty hip to people cheerleading here... ;)
Here's my take on running hot:
http://www.kennedydiesel.com/docs/LLY_Running_Hot.pdf
Now since I've written this, a couple of other tricks have emerged.
One is an Engine Oil Cooler offered by a guy going by "killerbee." There are only a couple of these out to the public and little testing has been done with BIG loads.
The other is a "pony" (secondary) radiator offered by a guy going by "TXChristopher." There are supposed to be a bit over a dozen of these out to the public with good results so far. There has also been limited testing with BIG loads, but Rick Lance has been towing heavy with good results. He still got hot, but now seems to have a failing fan clutch. He can comment further.
The thing I'd like to see is for someone to take my splash guard "prop down" mod and add a shroud between the OE splash pan and the radiator core support. The idea is to create a concentrated low pressure area for the air to flow to under the truck...
How should we proceed? And at what expense? I am confused to why it comes on because the temp reading on my attitude monitor changes by only 5 to 10, at the most. Let me know if you want to try it on my truck.
Stlheadake
06-19-2006, 08:51
Please don't blast me, why don't other brands have similar problems? I have never heard about a Ford or Dodge (stock) with overheating problems. I know that each manufacturer seems to have their own quirks, but this Duramax issue seems so insurmountable.
Why didn't the LBZ get a larger cooling system? Is GM acknowledging any real problems with the cooling systems? I am concerned that this issue will become the one thing that everyone remembers about this motor. Just like most people seem to incorrectly remember that the 6.2 engine was a conversion engine that really screwed up diesels and the marketability of diesels.
How big of an issue is this? One fella stated that his dealers solution to his overheating problems was an LBZ. I just wonder if they were admitting fault and considering that a resolution?
I haven't experienced any too hot situations (yet!), but I haven't really pulled in the heat yet. I did post a question about how hot is too hot, since I thought I was running hot.
redrider#1
06-19-2006, 11:22
When I first got my truck, I was concerned about the length of time and the noise caused by the fan clutch engaging, but since I straight piped it, I can barely even hear the fan come on anymore. I do hope some of the suggestions given help you out.
Mark Rinker
06-19-2006, 12:06
I listened to my fan clutch for what seemed like 30% of last week's 3,000 mile thrash. To me, its a comforting sound, but I know it wastes fuel.
There are three distinct levels to my '05s fan clutch, like OFF/LOW/HIGH.
To me, the best solution would be one that runs 'LOW' at coolant temps over 200, and 'HIGH' only when my coolant temp reaches 220...
Mine seems overactive, and my fuel mileage suffered last week as a result.
More Power
06-19-2006, 13:11
Why didn't the LBZ get a larger cooling system?
It did.... ;) See the 2006 Model Year (http://www.thedieselpage.com/features/2006MY.htm) article available on the web site.... :)
Jim
REDTRUCK05
06-22-2006, 21:35
I listened to my fan clutch for what seemed like 30% of last week's 3,000 mile thrash. To me, its a comforting sound, but I know it wastes fuel.
There are three distinct levels to my '05s fan clutch, like OFF/LOW/HIGH.
To me, the best solution would be one that runs 'LOW' at coolant temps over 200, and 'HIGH' only when my coolant temp reaches 220...
Mine seems overactive, and my fuel mileage suffered last week as a result.
Seems to me that it is a ambient temp clutch, It is either starting, on, or turning off as it senses temp. John, am I understanding this?
The clutch is affected by ambient temps, but moreso it senses that air temp thru the rad.
The clutch is designed to operate at 1500 RPM disengaged, and 3,000+ engaged. There's really no middle ground.
REDTRUCK05
06-29-2006, 21:39
That is the way I understood it.
Recently I've noticed that occasionally my fan stays locked up longer on the first trip of the day. It used to be consistant and always came unlocked at about the same point on my route, about 1/2 mile from the house. Since the warm weather started, there have been times when it stayed on for 2-3 miles. I can't discern any pattern other than the warmer weather.
Just food for thought...
REDTRUCK05
07-06-2006, 22:06
Recently I've noticed that occasionally my fan stays locked up longer on the first trip of the day. It used to be consistant and always came unlocked at about the same point on my route, about 1/2 mile from the house. Since the warm weather started, there have been times when it stayed on for 2-3 miles. I can't discern any pattern other than the warmer weather.
Just food for thought...
Now Imagine it on for 13-15 miles at a time, even longer at times. Everytime I come to a stop, or even drop below 50 mph. This can result in it being engauged more than 70 or 80 percent of my trip.
Recently I've noticed that occasionally my fan stays locked up longer on the first trip of the day. It used to be consistant and always came unlocked at about the same point on my route, about 1/2 mile from the house. Since the warm weather started, there have been times when it stayed on for 2-3 miles. I can't discern any pattern other than the warmer weather.
Just food for thought...
When stopped, the fluid can migrate and engage the clutch. The clutch then needs to "pump" the fluid out. The spec for this is something like 90 seconds at 3,000 clutch RPM.
As for Hot conditions activation described by Redtruck:
The fan clutch is your friend. If you suspect it is faulty, you could have the dealer replace it, but when you join the overheaters don't say I didn't warn you...
O&A party rock
07-09-2006, 05:34
thanks for posting that article
Excellent reading for someone who is taking delivery of 3 LBZ's for the company in 4-5 weeks-first company diesels, in pick-ups anyways.
I will keep reading up on it.
Great site, smart contributors, good vendors with good products and experience to back it up.
Thanks to everyone
REDTRUCK05
07-10-2006, 20:28
It did.... ;) See the 2006 Model Year (http://www.thedieselpage.com/features/2006MY.htm) article available on the web site.... :)
Jim
I thought it was one of the things done diferent in 06. Fan changes, tranny cooling changes and cold air intake changes. But i could wrong
REDTRUCK05
07-10-2006, 20:44
When stopped, the fluid can migrate and engage the clutch. The clutch then needs to "pump" the fluid out. The spec for this is something like 90 seconds at 3,000 clutch RPM.
As for Hot conditions activation described by Redtruck:
The fan clutch is your friend. If you suspect it is faulty, you could have the dealer replace it, but when you join the overheaters don't say I didn't warn you...
I understand that in the situation that I am in, the fan clutch is my friend. I agree 100%! What frustrates me is that i feel victim to poor design. Just as do many of you! I would feel even worse if I owned previous trucks with the same problem! As do many of you. It seems to me that GM could design an engine, like others, that do not RELY on clutch fan, but is there as an "extreme condition" cooling back up.
It seems to me that GM could design an engine, like others, that do not RELY on clutch fan, but is there as an "extreme condition" cooling back up.
If the fan always pulled hard enough for all but the most extreme conditions, your mileage would suffer!
REDTRUCK05
07-12-2006, 22:58
What i am trying to point out is that with the right design it should not pull in unless in extreme conditions. My dads LB7 does not pull in until he is in the foothills, and he pulls TWICE the trailer than I do. Mine 5600#, his 13500#. Pulling 13500# at 65mpg he gets 11 mpg. I pull 5600# at 65 I get 9-10 mpg and my fan runs everytime i come to a stop or drop below 60 mph...
Getting ready to pull out into the heat of July with my 2002 on trailer (11k+) with the 2005 LLY doing the tugging Montana bound. We've done this before with semi-frequent clutch activation, but manageable ECT using Edge module and Boost Stick. This year it's KD Custom tuning...
FWIW, a couple years back, we went from MT to CO with the 2002 EMPTY and had the fan clutch kicking in for miles at a time in some conditions.
SatchMax
07-13-2006, 21:25
I have had the same problem with my 05 ccda dually. I got the fan clutch changed and it was not as loud. Put the 4" exhaust on my truck and still does the same thing of running and not running. I have the juice with the monitor and the clutch will kick it at 225 and will run until it cool down to around 198 and before the new exhaust it would go down to 192. The dash guage would show 210. I have a question about the thermostats that are in these trucks. Some people have problems and others do not. Would it be wise to put two 180 or 190 thermostats in the truck and hold the temp down at a constant level and the clutch would not come on as much? I had one tech say that one thermo might be sticking and this could be a problem. Was wandering if anybody had put lower thermo in the lly to see if would help with the heating problem. My 02 ccda dually never had this problem with the 80000 miles that I put on it.
Thanks
SatchMax
Lubbock, Texas
REDTRUCK05
07-27-2006, 21:13
If the fan always pulled hard enough for all but the most extreme conditions, your mileage would suffer!
I dont think you are understanding my point.... I agree the fan is my friend. What I am saying is that the 05 lly is pulling in way too much. I have owned two other diesels without trouble. The only time they engauged was under extreme conditions. My LLY pulls in under light loads, its loud, its a huge load on an allready too thirsty engine.
At speed I think you would be surprised how little power that fan takes when the clutch is engaged...
REDTRUCK05
07-31-2006, 21:02
At speed I think you would be surprised how little power that fan takes when the clutch is engaged...
I might be wrong John, but it seems to me, the higher the RPMS, the more resistance to the Engine? With the cruise on at 50MPH (high traffic on 2 lane country road) when the fan engauges, the truck slows instantly. Sorry for beating this subject into the ground, but it makes me angry because I am unhappy with the mileage to begin with.
SatchMax
07-31-2006, 21:07
I just returned from a 800 mile trip pulling my 12000 lb fifth wheel. As I entered the north Texas around Dalhart I ran into a 30 to 40 mile per hour head wind. Across NM my truck would go from 190 to 225 and average out at 198 most or the time. When I hit the head wind the clutch ingaged and the temp went from 198 to 205 and up to 235 at times and did not stop running until we stopped in Amarillo for supper. Once we started again it did the same thing until the wind let up and the temp died down. Once the temp reached 235 and the egt went to over 1350 on level ground at 60 mph. What is the normal running temp of these motors. Also I burned a full tank of fuel in the 220 miles. This lly motor is not fuel efficient and I am wondering if anything can be done to help it out. My fuel mileage goes to hech when I am pulling my rv or my flat bed trailer when the fan clutch is in and out all the time. Does any body bave any answers.
SatchMax
Lubbock, Texas
05 ccda with edge attitude and 4" cat back exhaust
I might be wrong John, but it seems to me, the higher the RPMS, the more resistance to the Engine? With the cruise on at 50MPH (high traffic on 2 lane country road) when the fan engauges, the truck slows instantly. Sorry for beating this subject into the ground, but it makes me angry because I am unhappy with the mileage to begin with.
The faster you go (theoretically) the more ram air you have and the less psi drop across the cooling devices.
On dyno runs you'll see 10, maybe 20HP drop if the clutch is engaged.
mark45678
08-01-2006, 13:38
I know this is a little off topic ..my 17000 mile lbz fan never cam on today , it has in the past so I know it works. Todays its 97*f and sunny , coolant temps stayed right at 195~200 *f and never moved . I cant say the same for my 2004.5 lly truck the E.C.T would have moved over 210 even on the slightest of grades.... there maybe a poss upgrade going to 2006 parts , any one know for sure?
REDTRUCK05
08-01-2006, 22:08
Please don't blast me, why don't other brands have similar problems? I have never heard about a Ford or Dodge (stock) with overheating problems. I know that each manufacturer seems to have their own quirks, but this Duramax issue seems so insurmountable.
Why didn't the LBZ get a larger cooling system? Is GM acknowledging any real problems with the cooling systems? I am concerned that this issue will become the one thing that everyone remembers about this motor. Just like most people seem to incorrectly remember that the 6.2 engine was a conversion engine that really screwed up diesels and the marketability of diesels.
How big of an issue is this? One fella stated that his dealers solution to his overheating problems was an LBZ. I just wonder if they were admitting fault and considering that a resolution?
I haven't experienced any too hot situations (yet!), but I haven't really pulled in the heat yet. I did post a question about how hot is too hot, since I thought I was running hot.
This is a gm site, and what I find when asking questions about the fan and the the cooling system is that I should feel good about hearing the fan engauge in normal conditions. I feel you people were victims of a bad cooling system before because it over heated and did not pull in. Now it is a bad system and pulls in way to much. Now I am a victim of a poor redesign of a poor design to begin with
my o6 LBZ with 1500miles does the same thing. this weekend I was pulling my trailer 8500# for 1hr @ 70mph when i slowed down because of traffic (around) 10mph the fan kicked on and everyone around was looking to see what that noise was, it is REALLY loud only happened when I slowed to a crawl and ran for a few minutes, as for the milage I am geting 8.5 hwy with the above trailer and 19 without
ronniejoe
08-02-2006, 04:57
This is a gm site, and what I find when asking questions about the fan and the the cooling system is that I should feel good about hearing the fan engauge in normal conditions. I feel you people were victims of a bad cooling system before because it over heated and did not pull in. Now it is a bad system and pulls in way to much. Now I am a victim of a poor redesign of a poor design to begin with
Here's my suggestion, then... Go buy that Ford or Dodge and be happy!:rolleyes: It doesn't sound like you will be happy until you unload your piece of junk Chevy.
In reality, I will never understand your complaint about the fan running, because it is really counter intuitive. Maybe you have some hidden cooling system engineering genius that you could share with GM?
As a bit of anecdotal evidence, I was sitting next to an 18 wheeler the other day at the bottom of a hill at a stoplight on a 4-lane state highway. When he began to pull away, the fan clutch was engaged and it sounded like it could suck small children in. This was a Cummins powered truck, by the way. It was about 95F, he was comfortably driving in his air conditioned cab...not complaining about fan noise. A little ways up the road it dropped out. Hmmm... there must be something wrong with his cooling system.
I remember the late 70's and early 80's when clutch fans first became wide spread on all of the major makes of vehicles. GM, Ford, Dodge trucks...all gassers. Those things would drown out the sound of the engine they were so loud.
To get what you want, the frontal area of the truck would have to increase by at least three times to get a large enough heat exchanger in there to do the job without ever engaging a fan clutch. Then you would complain about poor aerodynamics (which the Fords and Dodges have).
Increased emissions control causes an increase in heat rejection from the engine. You can see that if you look at cooling systems across the years. That means you need to move more air to keep things cool.
Did you ever consider the possibility that there's something wrong with your fan clutch? Seems no one else is noticing theirs running as much as yours, and you stated yourself that the ECT wasn't high, so maybe it was not supposed to be on.
REDTRUCK05
08-15-2006, 22:37
Did you ever consider the possibility that there's something wrong with your fan clutch? Seems no one else is noticing theirs running as much as yours, and you stated yourself that the ECT wasn't high, so maybe it was not supposed to be on.
Thanks for the constructive input without all the sarcasm. I did explore this option, the dealer replaced the fan clutch at no charge. It resulted in no change. I do know that in 06 they redesigned the cooling system, and what I am hearing from two friends that pull heavy all the time is much less fan noise.
REDTRUCK05
08-15-2006, 22:57
Here's my suggestion, then... Go buy that Ford or Dodge and be happy!:rolleyes: It doesn't sound like you will be happy until you unload your piece of junk Chevy.
In reality, I will never understand your complaint about the fan running, because it is really counter intuitive. Maybe you have some hidden cooling system engineering genius that you could share with GM?
As a bit of anecdotal evidence, I was sitting next to an 18 wheeler the other day at the bottom of a hill at a stoplight on a 4-lane state highway. When he began to pull away, the fan clutch was engaged and it sounded like it could suck small children in. This was a Cummins powered truck, by the way. It was about 95F, he was comfortably driving in his air conditioned cab...not complaining about fan noise. A little ways up the road it dropped out. Hmmm... there must be something wrong with his cooling system.
I remember the late 70's and early 80's when clutch fans first became wide spread on all of the major makes of vehicles. GM, Ford, Dodge trucks...all gassers. Those things would drown out the sound of the engine they were so loud.
To get what you want, the frontal area of the truck would have to increase by at least three times to get a large enough heat exchanger in there to do the job without ever engaging a fan clutch. Then you would complain about poor aerodynamics (which the Fords and Dodges have).
Increased emissions control causes an increase in heat rejection from the engine. You can see that if you look at cooling systems across the years. That means you need to move more air to keep things cool.
Your input is appreciated, even as sarcastic as it was. My point to you and anybody else interested is this, I have owned other diesel trucks and pulled my same trailer with them with NO problems! It would seem the new cooling system in the 06 LBZ has this issue improved. I have said this before and I will repeat myself. You feel some kind of warm fuzzy feeling because the fan engauges. Most likely because you were a victim of another poor gm cooling design? I see it as a pain in the ---. I do Know when my 6 yr old boy says "dad whats that sound can you turn up the movie?" There might be a problem!
Stlheadake
08-18-2006, 05:30
When I started this thread, I was curious why MY fan clutch would come in and drop out. Again, MINE is most noticable in the morning when I start it. If I let it idle for 10 minutes or so, I get less fan clutch noise when I pull away than when I let it dile less.
I live on a fairly steep hill, and I have to head up hill when I leave my drive. This is when the fan is really noisy. I have pulled my travel trailer (around 10k) 200 miles when it was 100 degrees outside. I didn't hear the fan at all while I was moving.
When we stopped to fuel or grab a bite to eat the fan was expectedly engaged until I got back on the interstate. I am just curious why it is so noisy in the morning when I first start it up?
I don't know what all the hating is about. The noise is loud, and if mine did it like Redtruck is describing, I'd be complaining more!
I am just curious why it is so noisy in the morning when I first start it up?
I don't know what all the hating is about. The noise is loud, and if mine did it like Redtruck is describing, I'd be complaining more!
The clutch will often run when cold due to the fluid settling. The spec I believe is 90 seconds at a particular RPM (3k?) and it should go out. I don't like to run a cold engine fast, but next time it does this pull it up to 3k and time it.
If Redtruck's clutch has been replaced and it is still running excessively, there is a reason. Something is running excessively warm and or not cooling properly.
My fan only comes on when transmission temps hit 200 degrees. As soon as the trans cools down, the fan shuts off. I think GM might have realized this for '06 when they moved the trans cooler to the bottom of the cooling stack, and out of the center where the heat coming off the cooler blows directly on the fan clutch thermostat.
WhiteMax
08-20-2006, 19:40
My fan seems to run an awful lot. I have a feeling mine would be a o'heater if I put a load on it. There is no reason for these trucks to run like this except for a bad design. I feel it's qute sad that my fan needs to save my engine because I am running empty across flat ground. It's also a waste of fuel. I love my truck so I will put up with it until a sound fix is found.
Anybody ever measure compressor out temps to see just how much heat the intercooler is putting into the coolant? Ever measure AC heat load? Trans cooler?
The 2006 moved the cooler down out of the "dead zone" and also out of the ram air path. I'll be installing an improved version of the 06 trans cooler on my 2002 shortly.
REDTRUCK05
08-28-2006, 19:44
Anybody ever measure compressor out temps to see just how much heat the intercooler is putting into the coolant? Ever measure AC heat load? Trans cooler?
The 2006 moved the cooler down out of the "dead zone" and also out of the ram air path. I'll be installing an improved version of the 06 trans cooler on my 2002 shortly.
John, Can we use my truck and trailer as a guinea pig? I would be glad to take a day off of work, more if need be. You have the tools, experience and design capability to help us. I would even be willing to help with design costs...
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