• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

Erratic Temp Gauge help

Max R

New Member
Joined
Apr 8, 2014
Messages
3
Reaction score
0
Points
0
Vehicle Year
1997
Make / Model
Ford
Transmission
Automatic
So I just recently noticed something strange with my '97 Ford Ranger. While driving home from work on the highway the other day, my temp gauge needle rose all the way to the red and the warning Check Gauge light came on. The instant the light came on the gauge went back down to the normal operating temp and the rest of the drive home was uneventful. No steam, no problems with the engine seizing up, so I figured it couldn't actually be the engine overheating.
Ever since, the needle will rise to ALMOST all the way up and then settle back down to normal after ~10 minutes of driving or so.

The needle will rise regardless of if i'm idling or driving at residential or highway speeds.
My coolant levels are fine and there doesn't seem to be any signs of a leak.

Any ideas as to what this might be? My thought is that it could be a bad thermostat but I'm not sure. Thanks guys!
 


Ruffinit

Member
Supporting Member
U.S. Military - Veteran
Joined
Oct 22, 2007
Messages
264
Reaction score
1
Points
18
Location
Muscatine, Iowa
Vehicle Year
1996, 2003
Make / Model
Ford
Engine Size
4.0, 2.3 Duratec
Transmission
Manual
It'll have to take a bit more looking, but from what you've stated, it very well could be a sticking thermostat. It'll take 30 minutes max to change it out (when it's cold) and cost you $15-25 with the O ring included. Use the factory temp thermostat. You don't need to drain your coolant, just put a big pan under the truck to catch what will come out (which won't be much).
 

RonD

Well-Known Member
Joined
Jun 2, 2012
Messages
22,010
Reaction score
5,331
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
If it only happens when engine is warming up, i.e. t-stat opening for the first time then yes, replace thermostat, 192degF or 195degF for Fords, not 180degF, cooler is not better for engine, just FYI

If it happens after warm up, temp gauge needle randomly goes up and down, then it is the cooling system by-pass valve or heater core, it is getting clogged up.
 

tmcalavy

New Member
Joined
Oct 6, 2012
Messages
872
Reaction score
8
Points
0
Vehicle Year
93
Make / Model
Ranger
Transmission
Automatic
Time to back flush your cooling system, then watch the temp gauge...when my thermostat went south it would rise and fall, rise and fall...so did the thermostat and temp sensor together. Note: go easy on the thermostat housing bolts, one of mine popped free but the other broke off flush...my fav mech had to get it out and install a helicoil...let both soak first in penetrating oil, then rock both back and forth to make sure they loosen correctly.
 

hank857

Member
Joined
Sep 13, 2012
Messages
254
Reaction score
2
Points
18
Location
tucson, az
Vehicle Year
1994
Make / Model
ford
Engine Size
4.0
Transmission
Manual
I had same problem, just tightened the crimp on the plug at the sender. I had replaced the sender and it still did it so all I could figure was a wire issue. No problems after tightening, but like anything else it could be just about anything from tstat as noted. But I would play with the wire 1st or even change the sensor, they have a tendency to go bad after a while.
 

Sponsored Ad


Sponsored Ad

Top