Temp for fan to come on -diesel motors
09-14-2017, 03:20 PM
#1
Senior Member
Thread Starter
Temp for fan to come on -diesel motors
Does anyone know what temp the engine fan kicks on for the 2008 diesel?
I dont like how hot my truck tends to run, especially towing and wonder if i could wire in a manual switch for the fan of change the temp for it kicking in using star??
Other day i had the hood up and the fan was not on at 206 on the cts edge gauge
Turned on the ac and it kicked right on, but i would be happier if it would come on earlier
I dont like how hot my truck tends to run, especially towing and wonder if i could wire in a manual switch for the fan of change the temp for it kicking in using star??
Other day i had the hood up and the fan was not on at 206 on the cts edge gauge
Turned on the ac and it kicked right on, but i would be happier if it would come on earlier
09-15-2017, 04:10 AM
#3
Senior Member
Thread Starter
Plutoe just for my knowledge do you happen to know how high the temp must be - without the ac on- for the fan to kick on?
Was reading some on sprinter forums where these guys are wiring a bypass switch of some type to manually kick on the fans when they want to- but i dont know if the sprinter diesel fan set up is the same
Was reading some on sprinter forums where these guys are wiring a bypass switch of some type to manually kick on the fans when they want to- but i dont know if the sprinter diesel fan set up is the same
09-15-2017, 01:01 PM
#5
MBWorld Fanatic!
I don't know the temp, but some "thoughts"...
206* isn't all that high, but I suppose your real concern - especially given that you are in Arizona - is more about if it's at 206* at idle, what does it go to when moving. Something to keep in mind is that it's not uncommon for temps to go higher at idle, as compare to moving. At idle, there is no air movement across the radiator - once you are moving, there is a natural "breeze" that helps to lower temps.
I don't know how "picky" the computer is that controls the fan, but if this were an older car, I wouldn't think twice about splicing into the wiring going to the motor and adding a simple relay/switch in parallel.
With my older Suburban (diesel), the cooling system was a known issue, especially when towing at and above max rated weights in the summer heat. After doing what I could to make sure the system was flushed out/cleaned out/operating to "norms", I tried a product by Red Line called Water Wetter. This is added to the coolant as i supposed to make the coolant more efficient at transferring heat. Wouldn't you know, it freakin' worked as advertised! In the exact same conditions - idling at the boat ramp in summer heat - the temp dropped a solid 20* compared to what I had seen before.
Note that before I tried the stuff, I only had concerns when idling (although the temps were still well under anything that would be a "problem". When I was moving, the temps stayed down.
206* isn't all that high, but I suppose your real concern - especially given that you are in Arizona - is more about if it's at 206* at idle, what does it go to when moving. Something to keep in mind is that it's not uncommon for temps to go higher at idle, as compare to moving. At idle, there is no air movement across the radiator - once you are moving, there is a natural "breeze" that helps to lower temps.
I don't know how "picky" the computer is that controls the fan, but if this were an older car, I wouldn't think twice about splicing into the wiring going to the motor and adding a simple relay/switch in parallel.
With my older Suburban (diesel), the cooling system was a known issue, especially when towing at and above max rated weights in the summer heat. After doing what I could to make sure the system was flushed out/cleaned out/operating to "norms", I tried a product by Red Line called Water Wetter. This is added to the coolant as i supposed to make the coolant more efficient at transferring heat. Wouldn't you know, it freakin' worked as advertised! In the exact same conditions - idling at the boat ramp in summer heat - the temp dropped a solid 20* compared to what I had seen before.
Note that before I tried the stuff, I only had concerns when idling (although the temps were still well under anything that would be a "problem". When I was moving, the temps stayed down.
09-15-2017, 07:48 PM
#6
Senior Member
Thread Starter
It is not the 206 that bothers me so much as the 225-230 heading uphill with the trailer...
This is talked about on the sprinter and sprinter rv forums, these guys added scan gauges etc and found out this motor is running 230 all the time on uphill grades
Any of us pulling trailers are hitting these numbers and i just am not happy with my motor running so hot
The manual actually says The truck can run up to 248 under heavy load or stop and go traffic, which is nuts to me
I think the overheat light comes on when you hit 248 if i am reading this right
With all the siudging etc being this hot seems like a bad idea
And my trans does not get near as hot
Reading on sprinter forums it seems the fan does not kick on until 220 or something like that, seems if it came on at 205 the whole motor would not get as hot....
Maybe plutoe can verify the actual temp
Good chance i will see about splicing in a switch so i can override and turn it on when towing
Vin number 4JGBF22E88A374319
This is talked about on the sprinter and sprinter rv forums, these guys added scan gauges etc and found out this motor is running 230 all the time on uphill grades
Any of us pulling trailers are hitting these numbers and i just am not happy with my motor running so hot
The manual actually says The truck can run up to 248 under heavy load or stop and go traffic, which is nuts to me
I think the overheat light comes on when you hit 248 if i am reading this right
With all the siudging etc being this hot seems like a bad idea
And my trans does not get near as hot
Reading on sprinter forums it seems the fan does not kick on until 220 or something like that, seems if it came on at 205 the whole motor would not get as hot....
Maybe plutoe can verify the actual temp
Good chance i will see about splicing in a switch so i can override and turn it on when towing
Vin number 4JGBF22E88A374319
09-17-2017, 04:02 PM
#7
MBWorld Fanatic!
I don't know the temp, but some "thoughts"...
206* isn't all that high, but I suppose your real concern - especially given that you are in Arizona - is more about if it's at 206* at idle, what does it go to when moving. Something to keep in mind is that it's not uncommon for temps to go higher at idle, as compare to moving. At idle, there is no air movement across the radiator - once you are moving, there is a natural "breeze" that helps to lower temps.
206* isn't all that high, but I suppose your real concern - especially given that you are in Arizona - is more about if it's at 206* at idle, what does it go to when moving. Something to keep in mind is that it's not uncommon for temps to go higher at idle, as compare to moving. At idle, there is no air movement across the radiator - once you are moving, there is a natural "breeze" that helps to lower temps.
In any event, use of electric fans---as opposed to belt driven fans--has long ago eliminated the "no airflow when stopped" problems seen in the last century.
OP most likely has no problem as during engine development MB quite likely fitted temperature sensors in multiple locations to determine temps at places where it really matters and designed the cooling system accordingly. Synthetic motor oils are great protection against heat problems, too. Really think there will be no return on investment in second guessing MB.
