Like the title says I am in need of a thermostat cooler than190* for my 99"IH 4900. I can't stand to listen the the roaring engine fan 1 more day. IH changed designed when they went to the electric engine so the older T-Stats won't fit.MY ears thank you.

JED

 

If you have an old one you could see if they could match it up to a lower temp one at a truck parts store like fleetpride? I sort of have the opposite problem as my Detroit S60 had the thermostats replaced shortly before I got it but they seem to be 150 degree ones? I've had the fan go on only once this summer pulling a long hill on a 95 degree day :shock: . Of course, it does run often with the A/C on at low speeds. I'd like it to run at least 175 in the winter - last winter it stayed down at 150-160 and that seems too low to keep the condensation down in the oil even though I had plenty of heat for the cab?

 

It could be the AC is causing the fan to cycle. With the advent of 134 refrigerant, the temps in the condenser are higher so the fan will kick in more often to keep the AC working properly. Also, the condener is in front of the radiator, so it will inherently make the water temp hotter, as the air gets pre- heated before it gets to the radiator.

Try rolling the windows down and running with the AC off to see if the fan still cycles as often. If it does, a cooler T'stat won't make any difference.

As far as finding a cooler T'stat, check with an International dealer, but chances are you won't find one, as the engines these days need to run hot for emissions.

 

Thanks guys Its not the A/C it works as it should at low speeds or idling. And IH doesn't sell a cooler T-stat becuase of emmisions. Its not like they have to listen to that roar all day long they could care less. I have tried many part stores no help there. I just can't beleive I'm the only person that hates to listen to that fan. I tried drilling 16 small holes in the T-stat made a small differnce just takes a little longer to gett to operating temp where fan kicks in.

Jed

 

Maybe you didn't understand, the AC works fine because the fan cycles constantly. Water temp is not the only thing that makes the fan cycle, the condenser temp does also. That is why I suggested you try it on a hot day without the AC to see if it is actually the water temp making the fan cycle or, the AC. If it is indeed the AC, changing the T'stat won't make any difference.

 

Changing the t-stat won't do a thing. The one you have is wide open before the fan turns on. There won't be a difference.

Also, engine wear increases exponentially the colder the engine gets.

You have a mechanical problem, fix it.

 

I beg to differ - my S60 seems to have 150 (or 160?) degree thermostats and takes a looooooong pull to get hot enough to kick the fan on. In the summer I'm usually averaging 175 degrees so I'm not too worried about it. But - when it was put on the road last November it rarely went above 150. One of the engine mfgs has something on their website saying that you should be above 160 to run right. Usually the hotter the engine runs the more efficient it is - I'm getting a half a mile per gallon better this summer over the winter but I don't know how much of that is normal seasonal variation and how much is engine temp?

 

Yes it will make a difference when the cooling system is functioning normally, but it wont make a lick of difference for this guy. His engine is already either running hotter then the current thermostat, or his fan is always on(mechanical problem).

If his current t-stat is always open, it wont make a difference even if he has a 120 degree thermostat in there. Unless the old one is not working correctly.

 

Ok Ihave drove this truck with the A/C off, the fan still runs nearly all the time running down the road 60mph. So the A/c is diffently ruled out The radiator is just 1 yr old as the fan hub ate it last summer. Ran the same with old rad and new rad. This is not just 1 truck they have 3 identical all fan runs nearly all the time. It is plainly a thermostat that runs to hot IH has said thats what they want. I can go drive wacth the temp and with the current t-stat it will run 205* hit a small hill or excellerate and the temp gauge climbs to 215* and fan comes on cools temps to 195* and repeats process over and over and over again. Know tell me that the T-stat is not too hot and the ecm is using the fan to regulate temp instead of letting T-stat do its job. IF the t-stat would fully open 10* earlier it would let the rad do its job instead of the fan jumping in and over riding everything. It is a lousy engineering job if you ask me. Again all 3 trucks act exactly the same. Thanks

Jed

 

That's normal behavior for today's engines.

Running at a steady 180 degrees is a thing of the past.