Cooling System Fix

[ixm3]

I recently went through a problem with the dreaded temp guage creep and wanted to share the troubleshooting and fix procedure.
Symptom: Properly operating temp guage creeps up into 3/4 area while in stopped traffic.
Checked: Fan clutch, (newspaper interference test). Fan seemed to work fine.
Auxillary fan operation: Fan never kicked in when guage went almost to red zone. First checked low speed fxn: fan kicks in on low speed when ac button is pressed. High and low speed aux fan work when radiator switch terminals are jumpered. Replaced temp switch at radiator just to make sure this wasn't a problem. Just for kicks also checked K1 and K6 relay function (unplugged relay while temp switch connections were bridged- resulting in dysfunction of fan).
Water pump worked fine and the radiator was relatively new.
Thermostat: Replaced it after all of the above...and this last item fixed the problem.
Temp guage now sits at 1/4-1/3 under the same conditions that it used to creep up.
Hope this helps someone...
-MJ

[jrawk79]

Wow, I'm having this same problem ! Don't really understand what you replaced other than the temp switch at radiator and the K1 and K6 relays ?!?

[slo325i]

I dunno what exactly turns on those aux fans but I went to summit and bought one of those temp switchs that directly works with the radiator temp (a temp sensor probe thru the radiator) and kicks the fan on automatically. You set the temp too. It's been working on my car for two years now w/o problems. Very simple wiring as well. It also has another wire for A/C operation as well.