Engine Cooling problem
1990 Lexus LS 400 V8 149, 00 miles
I have recently started having problems with over heating, I haven't noticed any leaks and replaced thermostat after testing it first. After doing so I noticed that my cooling fans wont come on during idle but wille come on during driving. Is this problem simply a relay or could I have more serious problems like a blown head gasket? And what is the best way to determine head problems?