M8 advanced oil cooler system
Seasoned HDF Member
Joined: Jan 2008
Posts: 13,632
Likes: 11,382
From: State of Confusion
no idea, but bet Steve, who provided the data knows this stuff inside and out
Stellar HDF Member
Joined: Sep 2013
Posts: 3,490
Likes: 610
From: USA
Not sure what to think with the conflicting stories as to when the fan should be on. Mine has never been on yet. Was at the dealer today and its enabled, the techs say it wont come on till the oil reaches temp. He did not know what that temp was but he says its not coming on in this cold weather unless I was to idle the engine a very long time.
After reading all these posts, I wonder if the tech was correct about the fan not coming on until the oil reaches a certain "unknown" temp. I have looked at the parts catalog for the M-8 and I can't find any mention of a oil temp sensor. I really doubt that the M-8 has any oil temp sensor when it's never been used in earlier HD bikes. HD doesn't even offer a oil pressure sensor that can display oil PSI like earlier bikes. Maybe the fan gets triggered by the engine temp sensor that appears to be mounted in the rear head.
Seasoned HDF Member
Joined: Jan 2008
Posts: 13,632
Likes: 11,382
From: State of Confusion
After reading all these posts, I wonder if the tech was correct about the fan not coming on until the oil reaches a certain "unknown" temp. I have looked at the parts catalog for the M-8 and I can't find any mention of a oil temp sensor. I really doubt that the M-8 has any oil temp sensor when it's never been used in earlier HD bikes. HD doesn't even offer a oil pressure sensor that can display oil PSI like earlier bikes. Maybe the fan gets triggered by the engine temp sensor that appears to be mounted in the rear head.
Stellar HDF Member
Joined: Sep 2013
Posts: 3,490
Likes: 610
From: USA
The 2017 Police Service Manual Supplement (94000387) or the 2017 Trike Models Service Manual Supplement (94000391) might have some information as the fan equipped oil cooler is standard on those models that have the M-8 air cooled engine.
I should say that I'm just curious as I don't own a M-8. Steve Cole seems to be very knowledgeable about these new M-8 bikes so maybe he'll provide the answer.
MJ - a quick question for you, does the oil cooler appear different from the stock one or is it the same cooler just with the addition of a fan?
I should say that I'm just curious as I don't own a M-8. Steve Cole seems to be very knowledgeable about these new M-8 bikes so maybe he'll provide the answer.
MJ - a quick question for you, does the oil cooler appear different from the stock one or is it the same cooler just with the addition of a fan?
Seasoned HDF Member
Joined: Jan 2008
Posts: 13,632
Likes: 11,382
From: State of Confusion
The 2017 Police Service Manual Supplement (94000387) or the 2017 Trike Models Service Manual Supplement (94000391) might have some information as the fan equipped oil cooler is standard on those models that have the M-8 air cooled engine.
I should say that I'm just curious as I don't own a M-8. Steve Cole seems to be very knowledgeable about these new M-8 bikes so maybe he'll provide the answer.
MJ - a quick question for you, does the oil cooler appear different from the stock one or is it the same cooler just with the addition of a fan?
I should say that I'm just curious as I don't own a M-8. Steve Cole seems to be very knowledgeable about these new M-8 bikes so maybe he'll provide the answer.
MJ - a quick question for you, does the oil cooler appear different from the stock one or is it the same cooler just with the addition of a fan?
Seasoned HDF Member
Joined: Jan 2006
Posts: 11,467
Likes: 2,996
From: Charleston, SC
So... still waiting to learn more.
Stellar HDF Member
Joined: Sep 2013
Posts: 3,490
Likes: 610
From: USA
Well I'm going to bet that HD is using the Engine Temp Sensor that is installed in the rear head. I say this because the 2 models that come standard with the fan assisted oil cooler (police & freewheeler) don't have radios so they also don't run Ambient Air Temp Sensors (no place to display the air temp info). And we know HD removed the oil pressure PSI display (not that either of these models could display it) in favor of "Check Oil' & "OK". Some say this was done to reduce customer inquires/complaints about oil pressure. Based on that assumption, there isn't any way that HD would now install an oil temp sensor that could provide info on oil temps. They would have to have a dedicated customer service rep just to answer the added calls. Also, when looking at the parts for the fan assisted oil cooler, there isn't any oil temp sensor or thermostat listed. Just my guess ... waiting for info from someone who knows.
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,868
Likes: 7,987
From: poway
Well I'm going to bet that HD is using the Engine Temp Sensor that is installed in the rear head. I say this because the 2 models that come standard with the fan assisted oil cooler (police & freewheeler) don't have radios so they also don't run Ambient Air Temp Sensors (no place to display the air temp info). And we know HD removed the oil pressure PSI display (not that either of these models could display it) in favor of "Check Oil' & "OK". Some say this was done to reduce customer inquires/complaints about oil pressure. Based on that assumption, there isn't any way that HD would now install an oil temp sensor that could provide info on oil temps. They would have to have a dedicated customer service rep just to answer the added calls. Also, when looking at the parts for the fan assisted oil cooler, there isn't any oil temp sensor or thermostat listed. Just my guess ... waiting for info from someone who knows.
What about the air inlet temp?
Makes sense on removing the oil pressure and not having oil temp. People would likely freak out..
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Joined: Feb 2011
Posts: 381
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From: WORCESTER,MA
Hey Nomad, It's a fact that ALL the oil doesn't go thru the Oil Filter of a Twin Cam ! I read somewhere the M8 uses the same oil filter as the Twin Cam? The Infamous Donny Peterson, stated in AIM, 10/15 years ago, that the Evo oil filter was 30 micron, the Twin Cam at the time was 10 micron, with a more powerful oil pump, than the Evo. Donny's theory was the Twin Cam filter was too restrictive, & with a more powerful oil pump, oil would back up, build pressure, & the By-pass valve would open, all too often! He thought using an Evo 30 micron would allow more oil to flow & be filtered. My understanding now, is the Twin Cam filter is 5 micron, is that correct? If that is the case, the more powerful M8 oil pump will back up oil, opening the By-pass valve, letting unfiltered oil into the motor & oil cooler, crap blocking oil passages ? Happy New Year, BJ
PS, I'd like to hear Steve Cole comment, on my comment!
PSS, While poking around here last night, before I went out to dinner, I stumbled onto WWW.ULTRACOOLFL.COM, check it out!
PS, I'd like to hear Steve Cole comment, on my comment!
PSS, While poking around here last night, before I went out to dinner, I stumbled onto WWW.ULTRACOOLFL.COM, check it out!