Well Doc, funny you should ask... I've now changed out my coolant 4 times (with distilled water each time), and each time I've only been able to remove 8.1 quarts. That said, and given all the research that I've done on this forum and others, I'm beginning to think that there are a lot of SRT owners out there that may have thought that they had changed out ALL of their antifreeze in the past by themselves, or that they thought that their mechanic had done it properly, when in fact neither is probably correct.

Hear me out on this one: The SRT6 cooling system is comprised of two systems; the engine cooling system and the intercooler cooling system. In total, they apparently hold 15.3 quarts, though the 2005 Chrysler Crossfire Coupe SRT-6/Roadster SRT-6 Spec sheet says 11.8 quarts. But regardless of what the actual quantity may be (i'm still investigating this and hope to write a complete antifreeze change narrative later), the service manual and other references state that the two cooling systems (IC and Engine) do not interact "mechanically" with each other in any way, shape, or form, and that their only common item is the cooling system reservoir, which is only used to replenish fluids to each system (the reservoir has two separate chambers).

So, if you drain the fluid via the engine radiator draincock, all you are draining is the engine coolant, and NOT DRAINING THE INTERCOOLER FLUID AT ALL. Since the intercooler system is completely separate from the engine cooling system, in order to drain the intercooler system you must either remove one of the lowest intercooler hoses connected to the "charge air cooler radiator," as it is technically called, or do it by the book, chapter 7, and drop the intercooler radiator and open up its own separate draincock (see picture). Only in this manner will you be able to drain the fluids from both systems (15.3 quarts?).

The real sticklers out there (me being one of them, i guess..) will probably note that even these techniques won't get out all of the old antifreeze, as some of it will still be stuck in the engine block. Now, to remove this there is apparently, at least on the Mercedes SLK32 AMG, a separate draincock attached to an engine block plug to help remove this remaining block antifreeze, but I haven't been able to locate it on my SRT... That said, we can still remove that small amount of engine block antifreeze by draining our systems as best possible, and then refilling the system with straight distilled water and then running our cars until the themostat opens, at which time they will all mix together. Then, just drain it again and add your mixture to yield whatever coolant mix you desire. (50/50 in my case. But remember not to keep just distilled water in your system for any long period of time because you will suffer impeller erosion, which is prevented by the lubricants in antifreeze.

But, to get back to my original premise, given what I've been reading, I believe that when a lot of SRT owners change their cooling fluid they are only draining the engine cooling side (8.1 quarts in my case) and not the intercooler cooling side, unless they drop or remove the charge cooler radiator and drain it as part of their procedure.


My long winded 2-cents. best regards -- bob