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Discussion Starter #1
I believe the previous owner (or some shop) may have replaced the fan clutch on my LLY with a cheap import clutch unit. It operates, but is pretty inconsistent where it applies and disengages. I don't expect it to be dead on exact same degree every time, but.....

First let me say I'm monitoring coolant temp on the EDGE CTS not just estimating the dash gauge. So here's my symptom.....

On the freeway with a light trailer and running 66MPH (roughly 1850RPM as I recall) I can hear the fan engage / disengage and it comes on around 200-208 and off anywhere from 195ish all the way down to 180 (fresh ACDELCO Thermostats BTW).
It has the cold engage at startup like most do, and disengages in a few miles until the coolant warms. I mean it operates 'somewhat' as I'd expect except for the big swings in the temp that it engages and disengages. One day I'll hear the fan come in at 200 or 203,, the next it may be closer to 210-215 before the fan engages, and not drop out until temp on the CTS says 185. Doesn't seem to matter if it's 80° outside or 117°,, if the AC is on or off... I can not make any correlation between outside temp, engine load,trailering or not, accessories on or off,, Only thing consistent is when I observe this on the highway and my speed and RPM at 65-68MPH .

Do the rest of you see significant inconsistent swings in clutch fan operation????
 

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Sounds good to me. What you don't want is for it to wait until over 230*F and then finally kick in. As you know, fan clutch engagement is a function of the temperature of the air through the stack (which means outside plus heat from the stack), engine speed, and time (it's a little slow to engage, then a little slow to disengage). With all of that, there's variability.

I have an auxiliary radiator (from engineer837 in the Peoria, AZ area), but mine behaves similarly to yours. It usually comes on between 210*F and 215*F, usually only on long, hot grades. It then drops to somewhere below 190*F (maybe even low 180's once in awhile). BTW, I strongly suggest an auxiliary radiator for all LLYs.
 

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Get the kodiak fan clutch. Best upgrade you can do. My temps never go above 190. Pulling a trailer up a 8% grade for 5 miles I saw 205, fan roaring away. Once I crested the hill my temps dropped right away to 185-190.
 

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Discussion Starter #4
Jake do you have any pictures and contact for them. I found a facebook page but no contact info

BlownL,, ny chance have a GM / ACDelco part # that will work onth eLLY???
 

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Not sure about the rules posting links, but if you found the facebook page for "cooler towing dot com", the website is actually the same name, without the spaces and, of course, a "." for "dot". A clever disguise, don't you think?
 

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Discussion Starter #8 (Edited)
Nope, It finds all sorts of industrial cooling tower buildings, and one austrailian by that name but no

coolingtower.com found in a search even

I'm wondering if it might be part of Ron Davis racing radiators???
 

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:rof
 

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How about Cooler Towing ? And yes, Ron Davis makes the radiators to specifications provided by Joe (engineer837 in the forums). I think the radiator number on file at Ron Davis is not a secret if somebody wants to build their own kit.
 

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Discussion Starter #11 (Edited)
Sorry guys, was out of town working for a few days...
Found the site, BUT I've bought 6 Rod Davis radiators (1 for the drag race car, 2 for my 94 4x4 and 3 now for my LS dune buggy.) and ALL but 1 have developed leaks at the tank to core welds. Only one of the 2 for my 94 pickup lasted more than 5 years,, NO MORE Ron Davis for me! Even when you show them the SAME failure in the 3 radiators, at the SAME exact weld, they still wont stand behind the $800 radiator more than 90 days. If it's 2 years out,, forget it, they arent interested. I understand LOTS of wrench twisters will hard mount a radiator in a rickety old flexing chassis and beat things up out flying through the desert and bitch because the radiator develops leaks. But that's not the case here. They consider too many radiators 'custom' and ALL custom jobs are FINAL no return no matter what. So NONE for me thanks.

That said...... The stack is good and clean. (Been there cleaned that got the dirty T-shirt to prove it) Radiator seems to be able to keep the coolant at 197 even on hot days and even moderate long grades towing, but when it does start getting warm (210-215+) on a hard pull.. the devil is out of the box and by the time the fan starts roaring it has a hard time getting the coolant back under 200 until I crest. We have a lot of STEEP 6-9% short grades here in Az and even though they may only be 2-5 miles long,, the narrow winding roads means a 20-30 minute pull at 20-40mph speed limit. With a 9500# trailer temps can get dicey by the time you reach a summit. If the fan clutch would kick in about 205ish like it 'should' I think it could maintain reasonable temps. I guess I just hate seeing the big (180 to 225°) temp swings. I mean sheeze, with aluminum heads and iron block ,,, with dis-similar thermal expansion rates,, and significant temp swings like this,, it's no freeking wonder the LLY has a bad rap for pushing out headgaskets!

Hook I agree, I don't think I want the fan in at everything above 170°, You live where its hot as hell too and know, that can be only 50-60° above ambient,, Don't think fan 100% of the time would work good. The cold start fan engauge wouldn't be over before the temp kicked in! ( LoL)

Sorry about the rambling.... So the question is..... Is that Hayden 2886 the "Kodiak" fan? and the one that comes in at 170°?
 

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Most of the Hayden's all come in at 170.

HAYDEN 2843 (fits your LLY) said:
Briefly engaged at cold start-up.
Engages at about 170° radiator air temperature, (about 30° lower than coolant temperature).
$69 @rock
might be worth the try.
 

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My first aux radiator (TxChristopher kit, radiator made by someone in Kingman, AZ, I think) lasted 11 years before leaking at the core-to-tank. I'll be very disappointed in the Ron Davis radiator if it only lasts 5 years! It is rubber mounted and I snugged it just enough to not move around, so hopefully it doesn't get stressed much. Time will tell!

But it really does fix the LLY cooling system!!
 

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Discussion Starter #14
Not to get off-track here but.......
Ya know what I don't understand,, and would be a small cost to Ron Davis (and the other high end radiator builders i.e. BeCool and Mishimoto..),,, They are all big on 'NO EPOXY, 100% WELDED CORE' .. That's great and it 'looks' really sweet. BUT why not build a small dam on the tanks and flood epoxy over those core-to-tank welds to solve the weak spot of these radiators and make them last a damn lifetime!!!! Sheeeeze how hard is this!

I guess they wouldn't crack, leak, and have you spending another $900 with them for another hu!! Quite a business plan isn't it.. sell it, have it last well past some VERY SHORT warranty, then make them come back for another (Sounds like GM and Microsoft to me!!)
I really miss the days when you paid the big money and bought the BEST because it was built to LAST, not built to line the pockets of the shareholders.

Sorry for the rant,,, just old and grumpy I guess.
I'm going to pull from the valley up to the show in Pinetop later this month. It will still be plenty hot around here so maybe I'll swap out the fan clutch for one of the 170° versions and just see how it does pulling through Salt River canyon.
 

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Discussion Starter #15
Welp, new Hayden 2886 clutch and belt tensioner / idlers ar here. Have a little 300 mile haul late this month to a car show, should still be hot enough to see if it all stays cool. Figure it's not that big of investment in $ or effort to see how it works for my particular towing / pile of parts. Thanks for all the help, advice and suggestions guys. MUCH appreciated
 

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I hope it works out for you. Let ya know the results!
 

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Discussion Starter #17
Welp, gota say our LLYs are without a doubt the easiest to change th efan clutch. I watched a few Youtube videos and the later LBZ and 2010 and newer trucks are a much bigger pain. Was easy peasy. AND,, I think I found the issue. There is nothing ferric on the clutch that would leave such a stain, so this has got to be a viscous fluid leak right??? Isn't the steel ball the 'plug' where it was filled?

http://www.small-block-chevy.com/images/Dmax/clutchleak.jpg

Didn't have time to go for a long drive but it is engaged for the first couple of miles then disengages like normal. It warmed and went to 197 and well,, never moved. Will find out in a couple of weeks but I think I got proactive and dodged a bullet .
 

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That looks like a bad fan clutch. Either way I’m glad it’s installed. Let me know how she does pulling now!
 

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Hottest I’ve seen pulling an 5-8% grade was 205-208.... never got hotter. And she cooled right down at the top of the hill.
 

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I’ve been wondering about my fan clutch. Original clutch and truck has 145k. I was pulling my 5’er home from the land of the mouse and heading up a long grade out of Montgomery, AL, in 100 degree heat. The truck hit 224 on my Edge with no fan engagement, and as soon as I crested the hill, it came back to 195-198 with a minute. This spring I pull the cooling stack and it was full of crap. I ended up taking the radiator to a shop to make sure it was clean inside and out. Replaced it with new thermostats and water pump. To me, the OEM fan should kick on before that and mine still comes on for 30 seconds at cold startup. I’m guessing it needs replaced. Anyone try Kennedy Diesels replacement fan?
 
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