RMsALFA

Everything always seems to happen to my vehicles in bunches

After putting my recent tire wear fiasco to right (hopefully), now I have a coolant leak - right out of nowhere. I'm coming to the conclusion it's the usual aux coolant pump issue, but I have a question for those that have had and fixed this problem...

WHEN does the aux pump run ? I mean, what are the parameters (if any) the ECM uses to enable it ? Is it coolant temperature activated ? Oil temperature activated ? EGT activated ? Or, does it just turn on for a set period of time when the key goes off ?

The reason I'm asking is because the leak doesn't happen ALL the time after shutting down (and never seems to leak when the car is running). When it DOES leak, it drops a few tablespoons of coolant which runs on to the ground from the passenger side front of the engine - through the plastic shroud. (BTW, the car has 112K miles on it and the water pump was replaced at 90K during timing belt service).

2.7Lturbo

it almost never runs..... like, i live in phoenix and mine never runs.... case in point. its kind of like a fail safe after runn cooler for the turbos should they get waaay too hot

RMsALFA

Hmmmm - that's not what I wanted to hear Maybe my coolant leak is from somewhere else...

So, does anyone know WHAT triggers the aux coolant pump and at what temperature ? ?

2.7Lturbo

the aux coolant temp sensor triggers the pump, blue located under the coolant resevior around that area, and its triggered to come on like over 250. also coolant runs though the aux pump even when its not on, its actually part of the main system, there is not redudant cooling system, just and after run cooling pump. your probably leaking fromthe aux pump. just had the same problem. 85 dollar part and a couple hours later (did the TB too ) i was done, no more leaky !