Don’t flame me. To split or not to split?
Don’t flame me. To split or not to split?
Hello everyone. I know split cooling questions come up almost daily in this section, but after searching the forum, I wasn’t able to find the answer to my question.
so, here it is...
I have 2006 E55 with 70k on it. A day after getting the car, H/E pump went bad and my IATs were stuck at 150* F at cruising speeds of 45-90mph on a 80*F day. Today, I swapped in new Bosch 010 unit, bled the cooling system and went for a drive. Now my IAT is at 8-10* F above ambient (80*F today) and after doing 40-150mph pull, temps went up to 143*F but dropped below 100* after about 10-15 second and recovered back down to 87*F after about 45 seconds.
From what I have read, it seems that my car’s IATs are abnormally low for being stock with no cooling mods.
most of the people report 20-25*F above ambient temperature on stock cars and that number drops down to 10-15*F after splitting.
My question is: In my particular situation, do you see that splitting cooling system could aid even lower IATs or are my temps already low enough and I should think about it?
so, here it is...
I have 2006 E55 with 70k on it. A day after getting the car, H/E pump went bad and my IATs were stuck at 150* F at cruising speeds of 45-90mph on a 80*F day. Today, I swapped in new Bosch 010 unit, bled the cooling system and went for a drive. Now my IAT is at 8-10* F above ambient (80*F today) and after doing 40-150mph pull, temps went up to 143*F but dropped below 100* after about 10-15 second and recovered back down to 87*F after about 45 seconds.
From what I have read, it seems that my car’s IATs are abnormally low for being stock with no cooling mods.
most of the people report 20-25*F above ambient temperature on stock cars and that number drops down to 10-15*F after splitting.
My question is: In my particular situation, do you see that splitting cooling system could aid even lower IATs or are my temps already low enough and I should think about it?
Last edited by PavelK313; Oct 5, 2017 at 02:58 AM.
Hello everyone. I know split qooling questions come up almost daily in this section, but after searching the forum, I wasn’t able to find the answer to my question.
so, here it is...
I have 2006 E55 with 70k on it. A day after getting the car, H/E pump went bad and my IATs were stuck at 150* F at cruising speeds of 45-90mph on a 80*F day. Today, I swapped in new Bosch 010 unit, bled the cooling system and went for a drive. Now my IAT is at 8-10* F above ambient (80*F today) and after doing 40-150mph pull, temps went up to 143*F but dropped below 100* after about 10-15 second and recovered back down to 87*F after about 45 seconds.
From what I have read, it seems that my car’s IATs are abnormally low for being stock with no cooling mods.
most of the people report 20-25*F above ambient temperature on stock cars and that number drops down to 10-15*F after splitting.
My question is: In my particular situation, do you see that splitting cooling system could aid even lower IATs or are my temps already low enough and I should think about it?
so, here it is...
I have 2006 E55 with 70k on it. A day after getting the car, H/E pump went bad and my IATs were stuck at 150* F at cruising speeds of 45-90mph on a 80*F day. Today, I swapped in new Bosch 010 unit, bled the cooling system and went for a drive. Now my IAT is at 8-10* F above ambient (80*F today) and after doing 40-150mph pull, temps went up to 143*F but dropped below 100* after about 10-15 second and recovered back down to 87*F after about 45 seconds.
From what I have read, it seems that my car’s IATs are abnormally low for being stock with no cooling mods.
most of the people report 20-25*F above ambient temperature on stock cars and that number drops down to 10-15*F after splitting.
My question is: In my particular situation, do you see that splitting cooling system could aid even lower IATs or are my temps already low enough and I should think about it?
I can't tell for peak temps because I added a smaller pulley at the same time, but based off my cruising temps it appears to have done nothing at best.
Super Member


Joined: Jan 2007
Posts: 979
Likes: 38
From: South Africa
2018 E63s AMG (Current) 2011 CL63 AMG (Sold) 2005 CLS55 AMG (Sold) 2004 C32 AMG (Sold)
I second that, I never really noticed a worthy difference after splitting the system. If anything there was maybe a few seconds better In recovery time. Certainly no night and day difference.
MBWorld Fanatic!
Joined: Jun 2014
Posts: 1,036
Likes: 169
From: Portland, Oregon
2019 Jeep Trackhawk, 2002 CLK55, 2014 911 Carrera
Splitting made Zero difference for me. FWIW I have a Killer Chiller with a 1.75 gallon tank, no H/X, and I left antifreeze in the intercooler circuit.
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MBWorld Fanatic!
Joined: Jun 2014
Posts: 1,036
Likes: 169
From: Portland, Oregon
2019 Jeep Trackhawk, 2002 CLK55, 2014 911 Carrera
Many people want it to work, but I haven't seen any verifiable, repeatable numbers to prove that it does. There are a ton of variables at play and it take a lot of effort to perform any meaningful tests.
Super Member


Joined: Jan 2007
Posts: 979
Likes: 38
From: South Africa
2018 E63s AMG (Current) 2011 CL63 AMG (Sold) 2005 CLS55 AMG (Sold) 2004 C32 AMG (Sold)
Bud there is so much bs around here it's unreal. Exactly for that reason everyone claims awesomeness about every upgrade... In my experience not so on a good couple of mods, hence me taking things in my way and doing proper logging etc. Personally I think the guys that have been there and done it keep the info they have learnt to themselves. Like the post above that was said, people want it to work so they believe what they want.
Bud there is so much bs around here it's unreal. Exactly for that reason everyone claims awesomeness about every upgrade... In my experience not so on a good couple of mods, hence me taking things in my way and doing proper logging etc. Personally I think the guys that have been there and done it keep the info they have learnt to themselves. Like the post above that was said, people want it to work so they believe what they want.
Super Member


Joined: Jan 2007
Posts: 979
Likes: 38
From: South Africa
2018 E63s AMG (Current) 2011 CL63 AMG (Sold) 2005 CLS55 AMG (Sold) 2004 C32 AMG (Sold)
Splitting definitely will not get your IAT's below ambient. Only time that will happen is with a killer chiller setup and you just cruising with hot outside air Temps. Then also if your spraying w/m onto the IAT sensor. Only other possibility I guess, i havnt tried it, is a trunk tank setup with ice in it.







