Ok after doing some searching I havent really found any answers but heres the skilly.

I changed my oil, tranny, rear diff, and anti-freeze for the winter. Ever since it idles around 2000 for most of the day, cold-warm, whatever. But every once in a while during the day it will go to the 750rpm range where it should be. Silly thing is we didnt do anything but change the fluids. We didnt touch the vac lines,TB,Throttle cable or anything. I am so confused why this would happen. Any ideas?? Thanks

 

You might have an air pocket in the cooling system. Burp it out. And, keep the recovery/overflow bottle topped off cold. Do not touch the rad cap when hot. And, make sure there are no leaks. Top of rad coolant only when cold.

Could just be a coincidence. How old is the thermostat? If it is more then 3 years old, just go out and buy a new one from the dealer.

 

air pocket believe it or not could cause this if the coolant sensor is not reading correctly

burp the system, draw all the air out then u should be fine

 

Ok thanks, how do I draw the air out??