• Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-
  • SN95 4.6L Mustang Tech

97 GT Engine Heat

  • Thread starter Thread starter 97WhitePonyGT
  • Start date Start date Jun 29, 2019
9

97WhitePonyGT

New Member
Jun 29, 2019
2
0
1
Texas
Jun 29, 2019
#1
  • Jun 29, 2019
  • #1
So recently, I've had some problems with my 1997 Mustang GT. Car was getting towards the end of "A" in "Normal" on the temp gauge. So I went ahead and check coolant levels, which were where they were supposed to be, and checked that the electric fan comes on, which it does.
Long story short, I replaced the radiator because it wasn't dispersing heat like it should and for the hell of it put a 180 thermostat in.

So even after a new radiator and 180 thermostat the car still runs at 214 degrees. It starts off great for a while and runs below middle like it should but then occasionally will go from below middle and keep going up.

From what I've seen there is no visible leaking from the heads if there was a head gasket leak, coolant levels are good, thermostat is new, radiator is new, cooling fan operates as it should, and the heater core is not clogged.

Any ideas as to what it could be?
 

wmburns

SN Certified Technician
Aug 14, 2009
5,892
514
204
Houston Texas
Jun 29, 2019
#2
  • Jun 29, 2019
  • #2
I have helped more than one person with an apparent over heating problem that turned out to be a system voltage problem. WHY? Because the dash temperature gauge is calibrated to system voltage. IF system voltage is low, this will make the dash gauge read high. This creates a situation where the motor isn't actually overheating but the dash says otherwise.

Howto perform charging system voltage drop test

Howto perform charging system voltage drop test

To anyone else reading any of my posts I usually include the line: Today's cars simply will not run right without a strong battery and charging system! Cut corners here at your own risk I'm a big believer in starting with the basics. As such I...
www.stangnet.com

FWIIW, 214 is NOT over heating.

Recommend cross checking the T-stat cover with an infrared scanning thermometer. Then you will know for certain IF the motor is over heating or not. This will help you to focus the trouble shooting efforts. After all, does it make sense to look for a problem in the cooling system IF the motor isn't really overheating?

Also, don't make the mistake of trying to solve an overheating issue by installing a lower degree T-stat. IF the radiator can't keep up, THEN a cooler T-stat won't fix the issue. In addition the cooler T-stat can cause issues with the PCM and fan control because the PCM will attempt warm up the motor by doing things like staying in open loop longer and changing the way that the cooling fans are cycled. Best to stick to the factory recommended 192 degree T-stat.

Here's some information on an affordable ODB2 scanner. This will help as it will provide what the PCM "thinks" the ECT value is. Further with this scanner's bi-directional capabilities it possible to easily trouble shoot cooling fan problems by "commanding" the low speed and and speed fan to run while verifying that the fans actually run. This is important to confirm the fans actually work on BOTH speeds.

ForScan ODB2 scanner w ELM327 USB

ForScan ODB2 scanner w ELM327 USB

While working on your car have you ever wanted: to find an ODB2 operational PID value (say fuel pressure or MAF)? How about graph a PID value over time? Or compare multiple PID's over time? Access a bi-directional PCM control such as test a...
www.stangnet.com
 
Last edited: Jun 30, 2019
9

97WhitePonyGT

New Member
Jun 29, 2019
2
0
1
Texas
Jul 2, 2019
#3
  • Jul 2, 2019
  • #3
Solution was found:
I noticed some coolant running from the lower radiator hose, noticed a rather large pile after about 20 minutes of it being parked. The lower radiator hose had a crack and was not holding pressure and was leaking coolant. Temperature has been staying down ever since.
 
You must log in or register to reply here.

Similar threads

K
86 GT Water Pump
  • Kade5114
  • May 11, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
3
Views
76
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- May 11, 2026
nickyb
M
1997 Mustang GT Overheating Issue
  • Mustang1988!!
  • Sep 3, 2025
  • SN95 4.6L Mustang Tech
Replies
5
Views
209
SN95 4.6L Mustang Tech Sep 24, 2025
squeak93
B
97 GT with 03 explorer Eddie Bauer edition 4.6l
  • basbill73
  • May 10, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
2
Views
45
1996 - 2004 SN95 Mustang -General/Talk- May 11, 2026
squeak93
A
2001 Mustang GT, scorched metal smell and noise from trans/diff?
  • AndyE2255
  • Dec 1, 2025
  • SN95 4.6L Mustang Tech
Replies
4
Views
416
SN95 4.6L Mustang Tech Dec 28, 2025
gkomo
B
A/C Issues
  • Boats90GT
  • Jun 10, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
2
Views
64
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jun 11, 2026
Mcmahst
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-
  • SN95 4.6L Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?