This is driving me crazy! Two weeks ago my IAT2 would sometimes go up to 150 when driving then return to normal. Poppe the hood and noticed the pump wasn't on at idle so I checked the fuses and the relay for the aftercooler and they all were good. So I thought the pump was bad so I swapped it out with a new one and still at idle barely any coolant flowing to the resevior? Anyone have this happen to them?

 

At idle i've gotten up to 160 IAT2 in traffic on a 90 degree day and i have dual pass as well. I know the coolant pump power depends on rpm, so it runs full at WOT, but idling it just pumps a little. Pretty sure its normal, also depends on when the coolant fan turns on because no air flow = barely any heat transfer through the intercooler. What kind of temperature weather and for how long do you let it idle til it hits that temp?

 

How does the pump depend on rpm? I thought it was just connected to a power source?

 

if that is the case the pcm would be controlling the pump with duty cycle (switches the pump on and off quickly). if that is the case a good mod for anyone who drag races would be to put the cooling fan and intercooler pump on a switch to allow them to have it on in the staging lanes and pits.

 

i nothiced mine doing it to the other day i drove to the gas station a mile down the road and noticed colant was low so i added some water only took 2 or 3 ounces started my car pump still not on i think its also thew a temp sensor

 

the IC pump is just an I/O set up, on or off, no RPM dependency.

you might just be outta wack and think its week.

when your just sitting in traffic with the TB closed down to >3% and minimal air movement thats just gonna happen!

 

maybe i'm wrong about the varying power vs. rpm, i thought i heard it on here somwhere before, but i also noticed my pump barely runs at idle. It may only have two wires going to it, but the power going through the wires depends on the aftercooler pump relay and the computer. I also tested the voltage with my voltmeter and i only saw a couple volts coming out for a pump that takes 12 volts.

 

i think you have some other unseen issue.

i tested mine a while back, when i was worried about the incorrect wiring that had happened on the IRLs and saw full voltage.

 

very well could be a problem on my end, i probably tested it wrong and made a quick assumption. For Eastcoastz though, 150 is high for WOT, but not idle. Like 06Black said, at idle with the reduced intake air through the TB and the low amount of convection through the heat exchanger your iat2s are going to go up quite a bit.

 

the pump runs the same at idle or at wot