Reduced IAT's - Pump rewiring
Member
Joined: Sep 2008
Posts: 95
Likes: 44
From: Rocklin, CA
'14 CLS550 , '86 420SEL
I went for a long drive this weekend and the car was consistently responsive regardless of flying down the freeway or in stop/start traffic. I didn't measure IAT before but on the freeway I did notice it around 10-15 degrees above the outside temperature displayed on the dash.
Member
Joined: Sep 2008
Posts: 95
Likes: 44
From: Rocklin, CA
'14 CLS550 , '86 420SEL
sent a Xentry scan to a my tuner for and of course these codes roused some alarm from them. He said 'The ECU tune already runs the intercooler at 100%.' I am assuming 100% is not the same as always-on, which is what this wiring does, correct. Anyone with an ECU tune does this mod or is it unnecessary when tuned?
Out Of Control!!
Joined: Jun 2004
Posts: 13,799
Likes: 3,230
2014 E63S; AMS 100 octane ECU dyno tune; EDOK TCU tune; BB intakes; sprintbooster
sent a Xentry scan to a my tuner for and of course these codes roused some alarm from them. He said 'The ECU tune already runs the intercooler at 100%.' I am assuming 100% is not the same as always-on, which is what this wiring does, correct. Anyone with an ECU tune does this mod or is it unnecessary when tuned?
Out Of Control!!
Joined: Jun 2004
Posts: 13,799
Likes: 3,230
2014 E63S; AMS 100 octane ECU dyno tune; EDOK TCU tune; BB intakes; sprintbooster
the benefits are simply to have less heat soak. It won't add power per se, just will preserve better the max power it's capable of making in ideal engine temp, intake temp, and ambient air conditions
Member
Joined: Sep 2008
Posts: 95
Likes: 44
From: Rocklin, CA
'14 CLS550 , '86 420SEL
that makes sense, I am going to revert the always-on wiring and see if I notice any difference in feel and on the monitors while driving. If there is no difference with this tune then one less P-code to worry about.
Out Of Control!!
Joined: Jun 2004
Posts: 13,799
Likes: 3,230
2014 E63S; AMS 100 octane ECU dyno tune; EDOK TCU tune; BB intakes; sprintbooster
Now I'm not sure what the merits or the detriments are to having the intercooler run after the car is off for 5 to 10 minutes. Maybe it's good to soak up the heat and circulate it, but if the car doesn't have a fan running and it doesn't have any motion, I'm not sure what the absolute benefit is other than unnecessary 5 to 10 minutes of electronics stopping your battery and running electric motors unnecessarily.
MB World Stories
The Best of Mercedes & AMG
7 Craziest Things AMG Gas Ever Built
Verdad Gallardo
New Electric Mercedes-AMG GT 4-Door Coupe Unveiled: 10 Things You Need to Know
Verdad Gallardo
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)
Verdad Gallardo
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
Senior Member
Joined: May 2023
Posts: 459
Likes: 165
From: Endless Mtns. PA
2014 E63 AMG wagon 1965 Austin-Healey 3000 1970 AMC AMX
also, if you do the wiring method, what happens is the pump stays on for 5 to 10 minutes after the car is off and this is not the case when you do it via tune.
Now I'm not sure what the merits or the detriments are to having the intercooler run after the car is off for 5 to 10 minutes. Maybe it's good to soak up the heat and circulate it, but if the car doesn't have a fan running and it doesn't have any motion, I'm not sure what the absolute benefit is other than unnecessary 5 to 10 minutes of electronics stopping your battery and running electric motors unnecessarily.
Now I'm not sure what the merits or the detriments are to having the intercooler run after the car is off for 5 to 10 minutes. Maybe it's good to soak up the heat and circulate it, but if the car doesn't have a fan running and it doesn't have any motion, I'm not sure what the absolute benefit is other than unnecessary 5 to 10 minutes of electronics stopping your battery and running electric motors unnecessarily.
Out Of Control!!
Joined: Jun 2004
Posts: 13,799
Likes: 3,230
2014 E63S; AMS 100 octane ECU dyno tune; EDOK TCU tune; BB intakes; sprintbooster
Question- to remove or not to remove the foam like (fuel rail cover) spark plug coil covers on each bank? Do they serve a bigger purpose
Last edited by PeterUbers; Apr 29, 2025 at 10:15 PM.
Senior Member
Joined: May 2023
Posts: 459
Likes: 165
From: Endless Mtns. PA
2014 E63 AMG wagon 1965 Austin-Healey 3000 1970 AMC AMX
Well I did this too but after more reading it appears the main function is noise control although I'm sure they retain heat. I put them back on but didn't notice a change in noise.
MBWorld Fanatic!
Joined: Jun 2020
Posts: 2,138
Likes: 871
04 E55 AMG (totaled), 07 S550 4Matic, 14 E63S
I had my pump permanently on but after more mileage, I added a switch so i could set it back to stock. It's been set back to stock ever since. Personally I don't think much of this mod at all on a completely stock engine.
Member
Joined: Sep 2008
Posts: 95
Likes: 44
From: Rocklin, CA
'14 CLS550 , '86 420SEL
I wired it on with an inline fuse. I pulled the fuse yesterday before my weekly commute to the office, I think with the ECU tune the IATs remained about the same as with it wired on but I will keep an eye on it. I have been popping the hood after long drives as well also to keep the car on the tender as it is driven about once a week or less.
Joined: Nov 2016
Posts: 7,847
Likes: 3,498
From: Maryland
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Joined: Nov 2016
Posts: 7,847
Likes: 3,498
From: Maryland
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
I have not read through all the posts, but has anyone done this on the M276 biturbo engine? If so, where is the relay that you tap into? Thanks.
I've tried to find the relay using a wiring diagram, but without luck.
I've tried to find the relay using a wiring diagram, but without luck.
MBWorld God!
Joined: Dec 2019
Posts: 32,678
Likes: 6,419
Junior Member
Joined: Feb 2025
Posts: 71
Likes: 17
From: Central TX
E63
So for anyone with pre-facelift you really can't do the mod. I have a pre-facelift and added the split cooling to my car (didn't come with it stock) the coolant pump is tied into the cars cooling system so if you were to trigger the pump by a switch the cans will kick on as well. I've experimented with mine after installing a ICChiller to keep the pump going but doesn't work. Best bet is to get a trunk tank with an external controlled pump and do it that way
MBWorld God!
Joined: Dec 2019
Posts: 32,678
Likes: 6,419
So for anyone with pre-facelift you really can't do the mod. I have a pre-facelift and added the split cooling to my car (didn't come with it stock) the coolant pump is tied into the cars cooling system so if you were to trigger the pump by a switch the cans will kick on as well. I've experimented with mine after installing a ICChiller to keep the pump going but doesn't work. Best bet is to get a trunk tank with an external controlled pump and do it that way
Junior Member
Joined: Feb 2025
Posts: 71
Likes: 17
From: Central TX
E63
My guess is because the early models didn't have the split cooling system so the intergrade the 2 in tandem for faster cooling. Later models got the split cooling so they had to rewrite it
MBWorld God!
Joined: Dec 2019
Posts: 32,678
Likes: 6,419
Junior Member
Joined: Feb 2025
Posts: 71
Likes: 17
From: Central TX
E63
So I couldn't accept the fact that on the 2012 models there's no k60 relay like the 2014+ cars. Well after some long weekend digging I found it!. It's on the passenger side footwell under the carpet it's in the plastic wire organizer thing and covered by a foam. It's a small relay but it does control the intercooler pump. Now here's my issue since IDK how the 2014+ cars act and react. I have a poweprobe that I use to test circuits and whatnot. I used it on the relay and with the car KOEO grounding (brown/blue wire) it triggers the pump but once the cars running that wire goes to ground by itself. So now I'm asking is that how it's supposed to be? Are we just force grounding it to keep it going so it's not controlled by the ECU or? For you 2014+ guys does your ground have 12v on KOEO then straight to ground when cars running or is it always ground even with KOEO?
your car has the old ic pump bosch 010 with only 2 wires positive and negative and it is always powered on full speed 12v, you don't have to do the pump rewiring like the new pump.
