intelisevil
Well-Known Member
- Joined
- May 11, 2006
- Messages
- 324
- Reaction score
- 2
- City, State
- Sandy, OR
- Year, Model & Trim Level
- '00XLT-SOHC,'99Mounty-5.0
My '99 5.0 has always been a bit "cold blooded" taking 3-5 highway miles to warm up in the Summer. 192º on my temperature gauge (according to my OBDII reader) is about 1/16" above the bottom line of the arc.
Good coolant, radiator full, overflow tank at normal level. Thermostat replaced by Ford service department December 2014 (yes I got raped but I didn't have a covered work space . . .) Just turned over 267,000 miles, I've had it for the last 35,000 miles.
About a month ago (25º outside temperature on my usual highway drive) I saw the gauge go up to the middle for about five seconds , then drop down low, then stabilize at the "normal" 1/16" spot.
The next day I plugged in my OBDII reader and saw it go up to 213º, drop to 175º, then stabilize at 192º for the remainder of the drive including the climb from 1500' to 5500'. I work at a local ski resort on my "days off" during the Winter.
In the last week I've seen the High/Low cycle happen two & three times in the first ten miles, then stabilize before I start the climb. "Coasting" back down the hill it will cycle once before stabilizing.
Water pump or thermostat?
Thanks for your input,
Good coolant, radiator full, overflow tank at normal level. Thermostat replaced by Ford service department December 2014 (yes I got raped but I didn't have a covered work space . . .) Just turned over 267,000 miles, I've had it for the last 35,000 miles.
About a month ago (25º outside temperature on my usual highway drive) I saw the gauge go up to the middle for about five seconds , then drop down low, then stabilize at the "normal" 1/16" spot.
The next day I plugged in my OBDII reader and saw it go up to 213º, drop to 175º, then stabilize at 192º for the remainder of the drive including the climb from 1500' to 5500'. I work at a local ski resort on my "days off" during the Winter.
In the last week I've seen the High/Low cycle happen two & three times in the first ten miles, then stabilize before I start the climb. "Coasting" back down the hill it will cycle once before stabilizing.
Water pump or thermostat?
Thanks for your input,