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wil440

Recommended thermostat opening temp

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Another thermo question... Just flushed the cooling system today as truck takes a while to warm up, used Cat cooling system flushing liquid but I doubt I'd got enough to do the job properly so I'll have to get more and do it again but it has softened deposits I can see in the rad, backflushed heater core and engine/rad with water after draining the cleaner, took a look at the thermostat which was closed (cold engine) BUT tried to remove it and decided the only way it's coming out is scrap so I left it where it was for now so I can't tell what opening temp is fitted so whats the best to use ? truck is 98.5 2500 4x4 short quad.

I think looking at the colour of the coolant it was volvo earthmover 50/50 which is ok but thats been flushed and refilled with Cat ELC 50/50 I just need a gallon of Cat ELC top up which is not diluted to bring the mix to 50/50.

Also going to get a new water pump as the tell tale looked a little too damp for my liking

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I replaced mine in September.  Printed on the bottom of the thermostat is  CALTHERM 190F 3935824 9-99 DOWN so It's a 190°F.  I purchased a new thermostat from the Cummins dealer.  Part number 3946849, cost $43.99

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Thanks for the info, I'd bet it has the wrong thermostat in it as over here most are listed as 76c or 82c which converted is not 190f I need a 87c which is 190f.

Just ordered a dodge thermostat, gates belt and a water pump from rockauto for $120 shipped to the uk including vat @20% there will be a little more to pay when it all arrives but not much, genuine thermostat was $23, it will be cummins in a mopar box no doubt or could be chinese in a mopar box :) we'll see, all paid using paypal and shipped to the door

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I can't begin to imagine not being able to get parts easily and have them in less then a week without paying extras just because. You guys in UK are patient ha ha. 

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1 hour ago, Dieselfuture said:

I can't begin to imagine not being able to get parts easily and have them in less then a week without paying extras just because. You guys in UK are patient ha ha. 

It can be a challenge thats for sure, like the water pump... tell tale hole is a little damp so get one on its way, it may never leak or it may puke tomorrow, fan belt.... nothing wrong with it just get one anyway. The worrying item is the fuel pump if that decided not to play then that would be bad especially as vehicle recovery here as in RAC or AA or the recovery I have on my insurance, while they will sell you a policy they really aren't equiped to stick a ram on a tow truck or flatbed. I do know a good fuel shop though

I have owned american vehicles for closer to 30 years than 20 and I guess the interest started when I was a boy, I don't drive anything else but one of the 2 rams I've got, it's not patience, it's not being seen dead conforming in a EU/Jap rotbox, my wife has a brand new Nissan SUV, I detest the thing

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6 hours ago, wil440 said:

I've got, it's not patience, it's not being seen dead conforming in a EU/Jap rotbox, my wife has a brand new Nissan SUV, I detest the thing

Isn't almost like they are seeing how much sh.t people will take before they go :ahhh: lab rats is all we are, I feel at times......

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I'm the real odd duck here, and I''m still running a Dodge 200F t stat out of a 6.7L Cummins. She will bake food alright haha. Even at 0F out I can still see 200F temps out of my vents on MAX A/C in the winter.

She opens around 208F and cycles between 197 to 202F.

Edited by pepsi71ocean

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On 11/25/2018 at 11:21 PM, Dieselfuture said:

Isn't almost like they are seeing how much sh.t people will take before they go :ahhh: lab rats is all we are, I feel at times......

Too right. Quite a few years ago the deputy prime minister at the time in the uk  Prescott was his last name started preaching about vehicles in and around London and conjestion and pollution and that "we" should look to cut the number of cars on the road and the size.... this tool had 2 not 1 but 2 V12 Jaguars paid for by the tax payer to ferry him everywhere, he'd travel by train then one of his Jags would transport him the last bit...... 300yards was the smallest journey once, thing is his car had done the same journey as the train but without him just his driver LOL

 

On 11/25/2018 at 11:41 PM, Mopar1973Man said:

I'm the odd duck in the pile that has been mostly NAPA parts without any issues. I've got both a 190*F thermostat and a 180*F which is installed currently. 

I may have to have 2, got a 195 on the way so may need a 180 also

 

19 hours ago, pepsi71ocean said:

I'm the real odd duck here, and I''m still running a Dodge 200F t stat out of a 6.7L Cummins. She will bake food alright haha. Even at 0F out I can still see 200F temps out of my vents on MAX A/C in the winter.

She opens around 208F and cycles between 197 to 202F.

think that would be too high for here in the winter, although they say we are in for a bad one

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33 minutes ago, Mopar1973Man said:

Fan is completely removed. 180°F thermostat, operational temperature is about 185 to 188°F. I can sit and idle for long periods never rise above 172°F.

Why did you remove the fan?

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Glad you tried it. Some say they have experienced better mileage; never noticed the mileage increase personally, as locked hubs + winter diesel likely negate the fan/clutch removal effect.

 

 

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3 hours ago, Mopar1973Man said:

Experiment with the idea. Nothing more. Like right now sitting in the truck idling to stay warm. Sitting at 172*F.

I am sitting here, fan installed in about 38* weather idling at 175.

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4 hours ago, Mopar1973Man said:

Experiment with the idea. Nothing more. Like right now sitting in the truck idling to stay warm. Sitting at 172*F.

 

I've been known to remove the fan on the 01 in the winter time. I mostly do it because for some reason the fan clutch always lock in and stay locked no matter what in the winter on my 01 and I hate sounding like a Cessna taking off from the the local airport . I've tried 3 different fan clutches from different part suppliers and all of them end up staying locked up in colder temps. In the summer the clutches work perfectly fine :shrug:.

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10 hours ago, wil440 said:

think that would be too high for here in the winter, although they say we are in for a bad one

 

I tow with that t stat in the summer. I haven't seen much of a difference in temperatures other then it stats right around 197-202 even when towing. The motor is quieter at idle as the temperature rises above 195, I believe thats the ecm cutting the timing or fueling. @Mopar1973Man can explain this phenomena better. My mpg increased slightly from this mod, but the real increase is the IAT fooler.

10 hours ago, Mopar1973Man said:

15433504435472111000767.jpg

 

Fan is completely removed. 180°F thermostat, operational temperature is about 185 to 188°F. I can sit and idle for long periods never rise above 172°F.

 

I wonder what a 190F would do there mike?

 

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One i've got coming  is 195 but the one that's  in it seems low or stuck. It's seized in so couldn't check it

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4 hours ago, wil440 said:

One i've got coming  is 195 but the one that's  in it seems low or stuck. It's seized in so couldn't check it

 

usually when they fail they fail open. Its probably weak, my 190 I had in there from before was weak as well, and barely got to 185 under load towing. Sometimes they stick closed but you would clearly know that. the 195 is a great T-stat. My 200 is still in experimental phase even thought i've been running for i think 3 years now. But for winter operations its amazing.

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7 hours ago, pepsi71ocean said:

I wonder what a 190F would do there mike?

 

Just rise +10°F. That's all.

 

Like my idle temperature is the 172°F. Running down the pavement in a snowstorm I still saw 186 to 188°F. So if I changed for 190°F it would be idling at 182°F and running about 197°F the last I remembered. 

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1 minute ago, Mopar1973Man said:

 

Just rise +10°F. That's all.

 

Like my idle temperature is the 172°F. Running down the pavement in a snowstorm I still saw 186 to 188°F. So if I changed for 190°F it would be idling at 182°F and running about 197°F the last I remembered. 

 

Can I ask why your running a 180 instead of a 190 then? I didn't know if this had to do with pulling grades or something of the like?

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23 hours ago, pepsi71ocean said:

Can I ask why your running a 180 instead of a 190 then?

Just to experiment with the idea and see what truly happens. Any bonus, any loses, etc. So far I've not seen any huge loss of MPG other than a few tuning adjustments to gain it back. Last tank was 19.5 MPG running through a snowstorm. The only bonus I can see on this side is that you can keep the engine -10°F cooler and give more time pulling hard and heavy on a grade before it rises. That's about it. 

 

23 hours ago, pepsi71ocean said:

I didn't know if this had to do with pulling grades or something of the like?

Nope. Never had any kind of heat issues. I want to jump to a 200°F thermostat next to see if there gains or bouns on that side. 

Edited by Mopar1973Man
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Just got around to doing water pump, belt and thermostat. I ordered  a Mopar thermostat 5202 8185AC from Rockauto 195 degree, turns out it's not right, outer circumference is too small at 2 3/32nd versus 2 1/4 so 5/32nd too small, gasket sits in the groove instead of around the thermostat and no jiggle pin, it's in, sealed and working ok but took ages to bleed, now got to find the right one..... wrong parts test my patience due to the cost and the time it takes to get stuff

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58mm 24v with bypass disc, 190 degrees - 190F thermostat fully open at 207F, fan kicks in at 215F -

 

Mopar 05015708AC

Cummins 3946849

 

Both the above correct stats have a single jiggle pin, installed at 12 o'clock, as well as a rubber sealing ring around the flange.

Edited by ofelas
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2 hours ago, wil440 said:

Just got around to doing water pump, belt and thermostat. I ordered  a Mopar thermostat 5202 8185AC from Rockauto 195 degree, turns out it's not right, outer circumference is too small at 2 3/32nd versus 2 1/4 so 5/32nd too small, gasket sits in the groove instead of around the thermostat and no jiggle pin, it's in, sealed and working ok but took ages to bleed, now got to find the right one..... wrong parts test my patience due to the cost and the time it takes to get stuff

 

That's what my stats did. They fit into the grove, and not on the outside of it. That grove is to seal with the gasket. Although, when i bleed the system I leave the Tstat out and put it on once I'm filling the truck up and it gets up into the top of the head. I also park my truck on a hill and angle her so that side is the highest up too.

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