Overheating at idle
Thread Starter
Teching In
Joined: Apr 2026
Posts: 3
Likes: 1
Overheating at idle Hi all,
I recently bought a ’97 Trans Am, and it’s been running fine overall. I replaced the thermostat, flushed and refilled the coolant, and properly bled the system. However, it has started overheating at idle or when stopped at a light. On the highway, it stays at normal operating temperature with no issues.
This just started today. It’s about 90F outside, and every other time I've driven it, it's been a cooler day.
Any help or advice is appreciated.
I recently bought a ’97 Trans Am, and it’s been running fine overall. I replaced the thermostat, flushed and refilled the coolant, and properly bled the system. However, it has started overheating at idle or when stopped at a light. On the highway, it stays at normal operating temperature with no issues.
This just started today. It’s about 90F outside, and every other time I've driven it, it's been a cooler day.
Any help or advice is appreciated.
TECH Veteran
Joined: Dec 2008
Posts: 4,146
Likes: 62
From: Little Rock, AR
Define what you call overheating. Have you used a scanner to look at PCM reported temps and checked for fan operation when they are commanded on?
http://shbox.com/1/4th_gen_tech2.html#cooling
http://shbox.com/1/4th_gen_tech2.html#cooling
223F is perfectly normal while sitting and idling on a hot day. The sending unit, wiring, or the gauge itself might be failing. The sending unit is on the driver's cylinder head between #1 and #3.
