Hayden Fan Clutch

[Chevy1925]

I think i need to pull my thermostats and see just when and at what points they are opening. They are the mishimoto 180/185 but if they are really suppose to swing that much, that's not helping my overheating issues in the summer.

Wonder if anyone has pulled just the back t-stat for shits and giggles

 

[DIESELMAFIAPER.LB7]

So I'm lazy and don't want to read a ton into it but what's everyone liking the cheap o-riellys one that looks just like Kennedys or hayden?

 

[OregonDMAX]

I think i need to pull my thermostats and see just when and at what points they are opening. They are the mishimoto 180/185 but if they are really suppose to swing that much, that's not helping my overheating issues in the summer.

Wonder if anyone has pulled just the back t-stat for shits and giggles

Their website only shows 185/191 high temp or 174/180 low temp. I'm thinking about going with the low temp ones, I just shit my pants when I remembered I had two 190's in my truck now I know why it gets so hot so fast. I had them in there when I lived in Oregon and the coolant temp never got over 170.

 

[Chevy1925]

Their website only shows 185/191 high temp or 174/180 low temp. I'm thinking about going with the low temp ones, I just shit my pants when I remembered I had two 190's in my truck now I know why it gets so hot so fast. I had them in there when I lived in Oregon and the coolant temp never got over 170.

Then I have the 175/180s. I can't remember. It was 5 years ago lol

 

[c20elephant]

Maybe OEM t stats.. only time I've seen anything extra above 212* is when the fan clutch was worn out

Isn't that what most would expect when purchasing a thermostat an OEM, or at least one with the current changes GM had made from the original manufacture and we all know changes are made.

So I'm lazy and don't want to read a ton into it but what's everyone liking the cheap o-riellys one that looks just like Kennedys or hayden?

Oreillys does have some good quality parts. I purchased idlers and a tensioner that were identical to the ones on my truck with 70,000 miles. This more than likely will change to a Murray instead of a Gates in the coming years as they used to carry Hayden clutch fans but now have a Murray made in the USA...Oreillys is starting to sound like NAPA, made by Gates or whatever manufacturer with our name on it...
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Here is GM's explanation of how the thermostats work.
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Cooling Cycle (6.6L Diesel Engine)

Coolant is drawn from the radiator outlet and into the water pump inlet by the water pump. The coolant flows to the heater core while the engine is running. This provides the passenger compartment with heat and defrost.
Coolant is then pumped through the water pump outlet and through the coolant pipe to the engine oil cooler. The coolant flows around the oil cooler element and to the rear engine cover. The rear engine cover distributes the coolant flow to both banks of the engine block. In the engine block, the coolant circulates through the water jackets surrounding the cylinders where it absorbs heat.
The coolant is then forced through the cylinder head gasket openings and into the cylinder heads. In the cylinder heads, the coolant flows through the water jackets surrounding the combustion chambers and valve seats, where it absorbs additional heat.
Coolant is also directed to the turbocharger. There it circulates through passages in the center housing. During engine warm-up cycle the bypass valve located in the turbocharger inlet hose at the outlet pipe prevents coolant flow. During normal operating temperatures, the coolant assists in keeping the turbocharger cool.
From the cylinder heads, the coolant flows to the thermostats. The coolant flows from the thermostat housing to the water pump through the bypass pipe until the enginereaches 85°C (185°F).
Operation of the cooling system requires proper functioning of all cooling system components. The cooling system consists of the following components:

Thermostats (6.6L Diesel Engine)

The thermostats are coolant flow control components. The purpose of the thermostats are to regulate the correct operating temperature of the engine. The thermostats utilizes a temperature sensitive wax-pellet element. The element connects to a valve through a piston. When the element is heated, it expands and exerts pressure against a rubber piston. This pressure forces the valve to open. As the element is cooled, it contracts. This contraction allows a spring to push the valve closed.
The 6.6L diesel engine requires two thermostats for correct coolant flow. The front thermostat is a dual purpose thermostat. The front thermostat controls the coolant flow to the bypass port and to the water outlet. The rear thermostat only controls the coolant flow to the water outlet.
When the coolant temperature is below the rated thermostat opening temperature, the front thermostat valve remains closed to the water outlet and is opened to the bypass port. The bottom portion of the thermostat is raised off of the bypass port while at the same time the top portion closes the coolant flow to the water outlet. The rear thermostat also is closed to the water outlet during engine warm-up. This prevents circulation of the coolant to the radiator and allows the engine to warm up quickly. After the coolant temperature reaches 82°C (180°F) the front thermostat primary valve opening temperature, the front thermostat primary valve will start to open. The coolant is then allowed to circulate through the thermostat to the radiator where the engine heat is dissipated to the atmosphere. As the engine coolant reaches 85°C (185°F) and more coolant demand is required the front thermostat secondary valve begins to close the bypass port and the rear thermostat begins to open coolant flow to the water outlet. The thermostats will continue to control the coolant flow by opening and closing. The front thermostat will be fully open when the coolant temperature reaches 95°C (203°F) the rear thermostat will be fully open when the coolant temperature reaches 100°C (212°F). The thermostat also provides a restriction in the cooling system, even after the it has opened. This restriction creates a pressure difference which prevents cavitation at the water pump and forces coolant to circulate through the engine block

Engine Oil Cooler (6.6L Diesel Engine)

The engine oil cooler is a heat exchanger. The engine oil cooler is mounted to the left lower corner of the engine. The oil filter is attached to the oil cooler housing. The engine coolant flows around the oil cooler element. The oil cooler element is a series of plates. The engine oil temperature is regulated by the temperature of the engine coolant that surrounds the oil cooler as the engine oil passes through the cooler.
The engine oil pump, pumps the oil through the engine oil feed line to the oil cooler. The oil then flows down through the cooler while the engine coolant absorbs heat from the oil. The oil is then pumped through the oil return line, to the oil filter, then to the main engine oil passage.

Turbocharger Bypass Valve (6.6L Diesel Engine)

The turbocharger bypass valve is a temperature control valve. The valve is located in the turbocharger coolant inlet hose at the water outlet tube.
The purpose of the valve is to close the coolant flow through the turbocharger. Closing off the coolant flow through the turbocharger avoids turbocharger overcooling.

http://www.dieselplace.com/forum/4377955-post9.html

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[Chevy1925]

that description is very contradictory to the other post with the pic saying they fully open at 230. this one says at the latest they are both open by 212

 

[malibu795]

I rarely see anything above 92°C/198°F. To get that, is long grade 3+ miles and 5% or steeper
Normal operating temps regardless load in 95°F heat is 188-194°F or 88-90°C that's with a , LMM water pump, 82/85C or 180/185 Autozone t stats. And Hayden 2886 vlutch

All temps taken via V2 in black box scanning or actually logging

 

[malibu795]

I idle at 187-188 with AC on in 95° temps

 

[THEFERMANATOR]

I've run the aftermarket stats 1 time, and they ran ALOT colder than oem's. I believe 5hey go full open alot sooner, but even in Florida heat the truck had problems getting up to 180 at an idle. I know even running empty I see 185 if I'm doing less than 65, and 188-192 on my v2 running 70-75 empty down interstate.

 

[THEFERMANATOR]

So I'm lazy and don't want to read a ton into it but what's everyone liking the cheap o-riellys one that looks just like Kennedys or hayden?

The murray from oreillys is a repackaged hayden fan clutch. I think I got a bad one, but for the 1st 500 miles it would come in around 205-210 at slow speeds, and around 230-235 running down interstate. Then around the 600 mile mark it hust quit working all together. It had alot of resistance spinning it when cold, but it would not engage for nothing. Hit 240 on my way home on an 8% grade with my TT in tow, and it never attempted to engage. Hence why I spent the ectra money and got a KENNEDY this time. My old Hayden died after 5 years and about 60k miles, and the replacement didnt even make it 600 miles. The KENNEDY clutch is also built by HAYDEN but seems to be built to custom specs in all regards, so hopefully it holds out. If I had the extra 1/2" of room, I would have went with the 2886, but I didn't, so Kennedy's it was.

 

[malibu795]

I've run the aftermarket stats 1 time, and they ran ALOT colder than oem's. I believe 5hey go full open alot sooner, but even in Florida heat the truck had problems getting up to 180 at an idle. I know even running empty I see 185 if I'm doing less than 65, and 188-192 on my v2 running 70-75 empty down interstate.

What do you consider "operating temp" ?
Both the LBZ in my red dually and LMM mirror each other coolant temp wise.
Even without a trailer I hit ~160° within .5-1mile, in 50° temps, naturally it warms up faster with a 8k or heavier trailer on it, and 5 miles I'm 180-185°..
Short it takes longer to go from 160 to 180 than it does 50 to 160... Most likely its volume difference between coolant in block and coolant in radiator

 

[THEFERMANATOR]

To me operating temp is 180 and higher. The napa stats I put in an lly would QUICKLY drop back down to 165 or so within a few minutes of idling, so I stick with oem's for the extra seal around the poppet.

 

[malibu795]

Only time I'll drop below 185° while running, is going down long grades and no throttle input.. especially in the cooler months. I have seen the rubber grommets crack, that seal the tstat to the housing and one some how got caught inside the proper... How?!? No clue.. should've looked a picture

 

[malibu795]

Swamped in a new 2886.. it's not as aggressive as the others I've had... Heat soak is up mpg is down...
I'm might try tighten the spring up
Second thought is swap in a solid hub to run the fan 1:1 in the summer..

 

[gmduramax]

Just installed the 2886 in my truck. Coming from electric fans. 160 stats and in 105* temp empty truck it won't go past 180*. Cruising is usually 165 on flat ground. I can hear the fan start to come on at 170* so far I like it but I don't tow often.

 

[malibu795]

Just installed the 2886 in my truck. Coming from electric fans. 160 stats and in 105* temp empty truck it won't go past 180*. Cruising is usually 165 on flat ground. I can hear the fan start to come on at 170* so far I like it but I don't tow often.

I had 3 like such.. they would lockup at a stop light and be on through at least 2nd gear.. Current one won't..

 

[gmduramax]

I had 3 like such.. they would lockup at a stop light and be on through at least 2nd gear.. Current one won't..

Looks like I got a good one. I was worried but it seems to do fine. Well see how long it lasts

 

[whitetrash21]

Guess I missed this thread. You guys feel that rear shroud on the lbz trucks makes that big of a difference?? I left it off since I had to get the bracket off the block on the driver's side when I did the water pump. After f***in with that stupid shroud support for an hour, I was ready to send it into low earth orbit. My hands don't fit in those places.

Trucks not overheating, neither is trans but I notice my AC starts warming up when I idle a lot. Gonna order a Kennedy clutch based on what I'm reading.....but should I find a way to stick that shroud back in??

 

[Chevy1925]

I would put it back in if you tow. I don't think it will change your a/c much. If you have the blower speed way up and are at idle, you just don't have the air flow or compressor speed to keep the evap cold. Rev it up to 1500rpm and it will go back to cold. I'd put a high idle switch in if you do a lot of sitting in the old girl. I have one in my tracker to help it cool down when I remote start it

 

[Ron Nielson]

.....but should I find a way to stick that shroud back in??

ABSOLUTELY! When your REALLY need good flow thru the cooling stack, having the shroud attached to the back of the radiator will get the job done. Can get pretty hot in Vegas, if you are pulling any heavy loads, I wouldn't be without it. And yes, they are difficult to install. But worth it.