I happen to pull the engine cover off to replace the air filter with a microfilter only to discover that the supercharger coolant pressure overflow hose was positioned to drain coolant on top of the PCM. :holycrap: I immediately bought the car to the dealer and requested that they reroute the hose. All work was performed under warranty. Hose is now extended and routed to the bottom of the engine bay instead of being positioned to drain on any electrical components. :D

Good find!

I just took a look at mine and the overflow tube extends beyond the ECM (barely). It seems like if coolant were dumped out it might just miss the ECM. I agree that it is better to have the discharge tube further away so I am going to install a longer tube and route it down myself.

Doug

Pictures would help for the automotively illiterate. :) Thanks!

I will check my car out today. Can I ask which microfilter you went with? Are we talking about the air filter or cabin air filter?

SG

Because of concerns raised by this thread, I checked my supercharger overflow situation and found that the overflow hose installed extended considerably below the ECM. Was this done at the factory or by the dealer? I don't know, but there is no problem with my overflow hose.

Just checked mine...It was positioned to discharge to the side of the ECM. Fortunately, it was long enough to reroute to discharge below the ECM. Thanks for the Heads-Up :thumbsup:.

Dumb question , where exactly is the ECM ?

ECM is the abbreviation typically applied to the Engine Control Module. It is located on the 2009 CTS-V on the right rear corner of the engine when looking from a seated position in the driver's seat.

Thanks tedcmiller !
I noticed my discharge hose is to the right of the ecm just below it.

I will check my car out today. Can I ask which microfilter you went with? Are we talking about the air filter or cabin air filter?

SG

It is the cabin filter. I replaced it with a carbon filter from: http://www.allergybegone.com/cadilla...ir-filter.html OEM part number is GM02112C.

Your car's S/C coolant overflow is designed to drain outside to the environment ?

Your car's S/C coolant overflow is designed to drain outside to the environment ?


Yes it is. It does not go to an expansion tank... as it should I might add. While it is only a small amount if overflow occurs it ought to be contained and not dumped.

Yes it is. It does not go to an expansion tank... as it should I might add. While it is only a small amount if overflow occurs it ought to be contained and not dumped.

I guess I'm surprised, they did put a reservoir for the S/C coolant overflow on the STS-V.

lavaman,
I am not sure what you are suggesting would be such a good idea. If the supercharger coolant expands enough to overflow, and the overflow went to the engine coolant reservoir, then, when the supercharger coolant cooled enough to draw coolant back, it would mix engine coolant with supercharger coolant. Since engine coolant is exposed to a different set of contaminants, it might compromise the supercharger coolant.

My hose is several inches below the ECM. Really though guys, that ECM is waterproofed. After all it is under the hood where it is subject to all kinds of dirt and liquids and environmentally hostile things to electronics. I wouldn't worry about it.