90 SC temp issue

916supercoupe

Newbie
Joined
Jun 27, 2025
Messages
5
Location
Sacramento, CA
Vehicle Details
1990 Thunderbird SC 3.8 Supercharged
Country flag
Good morning ya'll,
Just picked up a 90 SC. Drives alright, but at idle the temp guage creeps up. I'm assuming its the thermostat, but I'm worried its the head gasket. I'm gonna do a block test as soon as I can. What do you guys think? Anything helpful is appreciated 🤟🏻😎
 
If it only acts up at idle, I would suspect the fan not coming on, which could be either the fan itself, or the IRCM.
Also is a little warm running uphill. Gets a bit up there, just past the M on norm. Still could be the fan?
 
Could be. Does the fan come on? How is the coolant

Could be. Does the fan come on? How is the coolant level?
90% sure the fan comes on when its supposed to. I drove it 2.5 hours back from where the previous owner had it with no issues, but that was highway. I haven't had much of a chance to drive it around town but when I do, she gets a little warm. Coolant level was perfect the entire time, needing no more once I got back home.
 
Gets a bit up there, just past the M on norm.

The SC runs on the hotter side; fans dont come on until over 220 degrees. My 94 gets up almost to the R before the thermostat first opens, when the fans come on it stays between R and high side of M but never really past that.

Even more so on a hot summer day; and if you're in 916 it gets really hot.
 
Not really .. it won't change the temp the fans come on at.
 

Similar threads

Back
Top