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Educate Me on Thermostats

Ok wait a minute... Your signature line doesn’t go through it.
What exactly are you running right now for the cooling system?
How old is fanclutch, radiator & its last full cleaning inside & out? Fan?
How hot is it getting? Only towing hard or whats the whole scoop?
 
I am sure that the radiator is OE. Coolant pump within the last two years. Kennedy Diesel fan clutch end of 2019.
Thermostats was the 195s.
Last summer, temp over 100 degrees, possibly close to 110.
Truck was empty except some blankets, sleeping bags and coolers.
Traveling between Colestrip and Decker Montana on our way to Tongue River reservoir. Some long steep hills along the way.
Temp gauge was reading next to 220 degrees. Thought the gauge might be off so pulled over, attached the Autel Maxi200 ALDL adapter to the port. Through the computer and temp sensor, the temp was right at 217 degrees. I guess the temp gauge was real close, or as close as a stock temp gauge can be.
Weird thing is, I never did hear the fan clutch kick in. I contacted Kennedy Diesel, He said that until the under hood temp gets to 180 degrees the fan clutch would not kick in.
I now have got the new coated Champion radiator in place. But have not as yet fired up the engine with it in the hole.
 
definitely too hot- that needs addressed.
My time spent chasing the waterpump would say get the Delco in there.

But turning on the fan when it is needed is way bigger if you couldn’t even tell it was on. When the fan comes on you HEAR it and feel the power drop. It will stutter your cruise control. Kennedy’s were usually rock solid, but a bad batch seemed to have happened.

If you can’t afford both- start with the electro viscous. If you can afford it do the pump and different clutch set up.
There is a few people running 4 bolt pumps with the hmmwv clutch with sucess reported. Personally i am convinced of the head damage and maybe still block crack on a couple of them long term- but normal overheating is gone.
 
Clean the stack, and a flush to wouldnt hurt if you haven’t done that in a few years too.
5 degree different stats won’t fix it.
 
Will L. said:
Clean the stack, and a flush to wouldnt hurt if you haven’t done that in a few years too.
5 degree different stats won’t fix it.
Click to expand...
Stack was quite clean. After getting the truck, going into the cold season, pulled the grill and loosed the engine oil cooler and trans cooler, had an old H2O extinguisher, detergent and water and soaked it all down then blowed it out through the fan blades.
There is no radiator shops here so not much of a chance of getting the old radiator tested for flow until I get to Billings.
 
Dont need a radiator shop. Before your next time doing work on the system, get a bottle of prestone flush from Autoparts store and follow directions to flush the system. It will clean out most of the rust from block and heads, and build up from inside radiator and heater core. If heater core or anything is new, it doesn’t hurt it. You drain antifreeze, then put in the bottle, fill with tap water. Run it 4-6 hours and shut off. Let cool for safety and drain. Refill with tap water and run like 15 minutes then drain again. Then ready for new antifreeze or in your case, tear apart system and make changes.
 
Will L. said:
I think those are before pics...
Click to expand...
Yup, just pulled and set it outside.
I have a new aluminum radiator from Chris that is now in the hole.
I did not use any solvents or cleaning agents on the condenser or on tje oil and trans fluid coolers and I now am wondering if that is something I should do.
Pull the new radiator, scrub the coolers and condenser with solvent, wash with detergent and water then rinse and blow dry.
Maybe that will be tomorrows project. Only bad thing is no floor drain in the garage but I have dealt with woreser. 😹😹😹
 
Pulled the new radiator, scrubbed the coolers and condenser with solvent, then attacked them with detergent and water and a thorough water rinse. Got the radiator back in, hooked up and the lower shroud back in place.
Time for a little nap, if I’m up in time, work it over a little more. If not, then, I have two real nice salmon fillets frum Costco thats calling out that they are needing some seasoning and grill marks. 😹😹😹
 
Hayden 2840 fan clutch (spin on clutch, will need a Duramax fan), remove the silicone holding the bimetal strip to the clutch body. Straighten the 90 deg bend in the strip completely. Then make a new 90 degree bend 1/8" closer to the end of the strip. RTV the strip back into the clutch housing and call it good. Fan will engage in the 180 deg range. You will hear it, feel it engage!
 
93detroit said:
Hayden 2840 fan clutch (spin on clutch, will need a Duramax fan), remove the silicone holding the bimetal strip to the clutch body. Straighten the 90 deg bend in the strip completely. Then make a new 90 degree bend 1/8" closer to the end of the strip. RTV the strip back into the clutch housing and call it good. Fan will engage in the 180 deg range. You will hear it, feel it engage!
Click to expand...
Would that be 180 degrees engine tempor is that 180 temperature under the hood ?
I do have a Kennedy Diesel fan clutch installed. Engine temp went to 217 degrees and I never did hear or feel it kick in.
I called KD and he said it needed to be 180 behind the radiator.
 
MrMarty51 said:
Would that be 180 degrees engine tempor is that 180 temperature under the hood ?
I do have a Kennedy Diesel fan clutch installed. Engine temp went to 217 degrees and I never did hear or feel it kick in.
I called KD and he said it needed to be 180 behind the radiator.
Click to expand...
I had mentioned this before, sealing the area around your cooling stack will increase stacks efficiency, because the fan pulls more air through instead of it flowing around the stack.
 
I don't know the under hood temp at which mine engages. I do know that by the time my temp gauge reaches two marks below the 210 mark, the fan clutch is fully engaged.
 
I think I was an unlucky one who also got one of the bad batch Kennedy clutches. Purchased last summer. When I raised my concern about the clutch not operating properly he seemed pretty indifferent. $200 wasted. I also got the Hayden 2886, going to try it first without modifying the spring, although it seems the ultimate solution is the electric version.
 
I had replaced the fan clutch a couple of years ago, over the parts counter unit. Truck running warm so I thought the KD clutch would help that. Not so.
I have heard the clutch in my old 93 gasser 350 would engage when the engine was first started, then after a short while it would quiet down. When it got real hot outside, I could hear that clutch kick in.
That over counter clutch I never did hear it kick in. Same with this KD fan clutch.
If anyone wants to comment on the operation of the fan clutch, please kick in what You have.
 
A little more on these thermostats.
I hung the stats on a piece of string. Using the wifeys candy thermometer started heating the water.
At 190 degrees the one stat cracked open. At 195 the other stat cracked open. Got the water temp to just over 200 degrees and this is how the stats looked at that temp. If they would open any wider I know knot. It seems that the water had quit absorbing heat about that temp.

64E5373F-32E9-4CB1-82F8-F1B0745C576F.jpeg
 
Going to put the 195s back in and see what the temp of the engine does with just the new radiator.
Then if necessary I’ll install the 190 stats and see what happens with those.
I know 5 degrees is not much but, if I can get the engine temp down to 212 from 117, that would be closer to a reasonable goal.
 
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