The fan will never lock up if it is working properly. However, if it is a thermal controlled fan , there should be a difference in resistance between hot and cold. If it is a viscous fan that is not thermally controlled it will be pretty much the same all the time. If it has a coiled flat spring like assembly on the front it is thermally controlled. If not, probably just a viscous fan. Bill Huff At 8/17/201105:03 PM, Keith Boonstra wrote: > > >And an update ---- > >Just repeated the scenario that made it overflow yesterday - idled for >about 10 minutes hot, then shut it down. I had no overflow this time, >so I'm guessing it just needed to get rid of a little coolant to have an >amount it considers an equilibrium. > >But I still wonder about the fan clutch. When I shut off the engine >hot, I can very easily spin the fan. Shouldn't the thermal action of >the clutch have it pretty much locked up in that situation? Or the >clutch supposed to only lock up when it's VERY hot? > >Keith Boonstra > >- > >On 8/17/2011 12:42 PM, paul wrote: > > On 8/17/2011 9:54 AM, Keith Boonstra wrote: > > > >> Well, here's the morning-after report. I had the cap tested this > >> morning and it is dead on 14 #, so we're OK there. There is about > >> 2-3/4" of tank between the core and the filler neck. The engine is cold > >> now, of course, and I'm showing 3/4" of coolant and 2" of air in the top > >> tank. This overflow situation has only occurred once so far, so if I'm > >> lucky (a pretty rare thing for me these days) the system is now down to > >> the amount of coolant it wants. I'll do a little watchful waiting. > >> > >> One thing I didn't think of doing at the time was to see if the fan > >> clutch was stiff when the radiator was overflowing. I presume I should > >> be able to feel that it is with the engine shut down while hot. I will > >> make it a point to check that the next time I have it heated up. > >> > >> Thanks to all. > >> Keith Boonstra > > > > Ok it sounds like your cooling system now might be at equilibrium, > > > > May I suggest that since you probably used a new anti-froze product to > > about a 50-50 mix, that you think about NOT letting that sit in your > > system the suggested 3-5 years. > > > > Once you have that air pocket established the modern formula not does > > react to the presence of the air very well. It probably will develop > > particulate fall out and can, given enough time, settle out and start > > building up 'crude'. Been there Done That in the 'hot-rod' truck > > parts chaser I have. > > > > Remedy, Annual flush and replace schedule. > > > > I adopted an abbreviated schedule for all our vehicles, even the > > modern closed system car. We really noticed this when we bought the > > used 98 Sebring convertible 8 or so years ago. And when we bought the > > wifypoo's used 05 PT GT R/T that was something I checked out after we > > got it home. > > It too got a flush and clean then replaced the coolant and it was only > > 3 years old then. > > > [Non-text portions of this message have been removed] ------------------------------------ To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx To unsubscribe from this group, send an email to bob@xxxxxxxxxxxxx or go to http://autos.groups.yahoo.com/group/Chrysler300/join and select the "Leave Group" button For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm For archives go to http://www.forwardlook.net/300-archive/search.htm#querylangYahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Chrysler300/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/Chrysler300/join (Yahoo! ID required) <*> To change settings via email: Chrysler300-digest@xxxxxxxxxxxxxxx Chrysler300-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: Chrysler300-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/