Rewiring Intercooler Pump - Lowering IATs




So... now i want to rewire it to possibly run all the time. Has anyone successfully done so? Are there any ill effects of keeping it on all the time, other than the obvious reduced life span? I am just worried that maybe the ECU cant adjust to 40°F IAT if it's setpoint is meant to be around a 100°F....?
Last edited by V-AMG; Jan 2, 2019 at 03:05 PM.




And how’d you do it? If you have a quick wiring diagram, or if you can explain what you did, that would be awesome.
I was thinking a 2-position switch; first position signal from ECU, other position is directly to a 12V source. I actually want to use my rear foglight button for it as i’ll never use the rear fog... and no fronts for some reason. What’s nice is thatthe rear fog illuminates on the dash, so i’ll know where I'm at.
I never did it on my E55, but all it took was one quick stab of the throttle and voila, came right on. I wish there was something like that here. Better yet, i wish I could get the temperature setting changed...
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Why the CEL? Is there feedback from the pump?
And how’d you do it? If you have a quick wiring diagram, or if you can explain what you did, that would be awesome.
I was thinking a 2-position switch; first position signal from ECU, other position is directly to a 12V source. I actually want to use my rear foglight button for it as i’ll never use the rear fog... and no fronts for some reason. What’s nice is thatthe rear fog illuminates on the dash, so i’ll know where I'm at.
I never did it on my E55, but all it took was one quick stab of the throttle and voila, came right on. I wish there was something like that here. Better yet, i wish I could get the temperature setting changed...
If I was going to do something like this again, I’d look into a higher gpm secondary pump wired to a switch either running on a bypass circuit or in line to increase flow when running prolonged boost. This way you can let the ECU do what it wants but still bypass it when needed.
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but yeah i think im done with modding the m157 just looking to help the overall longevity of the engine if possible
Btw, I take delivery tomorrow.

this shows a whole bunch of little injectors which is best for atomization but it's probably better to go with one big injector on each side those are less likely to get clogged up with debris. You don't ever want to have to go back in there the clean the injectors.






