While chasing a coolant leak I had drained the system, replaced the water pump, put new brushes in the auxiliary coolant pump, and refilled the main coolant system when I decided to again follow the manual's recommendation to bleed the supercharger cooling system. I had done this before (when I added a ground to the SC pump relay coil after discovering the ECU was not grounding it to run the pump) and it was no big deal.


But....this time I had a functioning auxiliary pump and had neglected to turn the climate system off when I asked my wife to turn the ignition on while I watched the SC fill port. With both pumps running now they created a small geyser at the SC fill port and even though I hollered to turn the ignition off again, the SC pump runs for at least 4 seconds after the ignition is off and in that time it drained the expansion tank and pumped a quart and a half of coolant all over the engine before it finally stopped. So...if you decide to bleed your super charger cooling system, be sure to turn off the climate system before you do.


There should be a big warning in the manual about this, but there is no mention of turning off the climate system except "Coolant may spill from supercharger fill port when ignition switched on." Yeah! I'll say! Big time! Like old faithful! No pics, though. I was too busy trying to put my thumb in the dike.

 

Having the the climate system off would not have changed anything Phil. You must have the plug in place when the ignition is on.

You do need to have the climate/heat on full when in the topping up process as that enable the heater core to be purged of air.

Also, obviously, the final top off is done when cool.

btw every time I have gone thru the refill process I have found the coolant in the SC plug hole to be topped up. Each time I did the refill on the level
not even with the nose up.

 

I did not have the geyser problem when the Aux pump was not running, but it now draws from the coolant tank when it runs.

The manual SC purge procedure does tell you to turn on the ignition with the SC plug out and I did have some bubbles come out of it before when the SC pump ran by itself. The coolant was almost at the top of the fill port when I first removed the plug this time so I should have let well enough alone. I had the front wheels on low ramps but when I added some at the fill port after the geyser fiasco, it seemed to back fill into the tank.

And yes, the plug definitely must be in to start the engine and purge the heater core. I let it idle for half an hour with the heater on HI and had 138 F air from the heater vents, but the engine temp never got past 197 F and the cooling fans did not come on.

The good news is that after the geyser coolant dripped off, there did not seem to be any coolant coming from the former leak. So far so good. Now to put the splash shield back on and take a test drive.

Got to get it done before 6:00 when The Ohio State plays Oklahoma; I'm a Buckeye alum married to an Oklahoma girl so we root for different sides, but I've got my lucky Buckeye ready and it worked the last time they played.