Thread: Another cooling issue. '98 N/A 3.8

I know, another one! I put about 150 miles on my car since the GTP radiator and trans swap. The car overheated on me over the summer on the highway and got a used GTP radiator. Did the upper and lower hoses and a 180* thermostat all at the same time.

Then it blew a brake line. Fast forward past finding a deal on a trans and doing a bunch of other ****, here we are. For the last 100 miles, the car has been running pretty cool, like ~ 1/4 on the gauge (150-170*). I recently plugged in the driver side door actuator for my dual climate setup (was unplugged when I got the car for some reason), so now my driver side has heat. Smells like someone took a dump, pickelled it in coolant, and threw it under my carpet though. Reeks of coolant inside the car with the hot air blowing.

This morning on my way to work through the snow/ice/freezing rain, the temp outside was 32*. The car would go from like 1/4 to a tad over half on the gauge and kept bouncing back and forth on the drive. Not erratic, but enough to where I was more concerned about the car overheating than the road conditions - all of this with the heat set @ 90* on high. (My new Falken tires were bad ass in the crap, by the way)

It just doesn't sound like it should be moving that much. I understand the gauge isn't all that accurate. I bled the coolant with the open-cap method and the screw on the thermo housing. It doesn't appear to be leaking coolant either.

So, would I be safe to assume it's either a heater core issue or the infamous "strange air bubble under the thermostat" that I saw Bill talking about when searching?

I took it to the store on my lunch break, (all of 4-5 mile round trip) and it didn't even crack 1/4 on the gauge. Runs pretty smooth, just has a slight issue at idle occasionally where my dash lights go a tad dim and the idle drops a tad. Real erratic and I can't duplicate it. I don't think it's related to the cooling though. Any suggestions or things to check are appreciated.

I don't whore out my car because it's pretty ugly, but here's a pic from today.

I have since found the issue and thought I'd update the thread. After a few days of watching the t-stat bounce around and having anxiety, I parked it in a parking lot that was on an incline. The car happened to be facing downwards. I happened to walk away from it and heard a hissing and saw some coolant dripping. After popping the hood, I discovered the culprit.

Radiator cap.

Replaced the cap with one from Advance Auto after topping it off with coolant, and it's been working fine. Stays steady around 145* on the gauge. Just did 150 miles of highway 70-80mph and it was great. Got a little warm when I slowed down but then cooled right back off. No missing around idle. Runs and drives like a new car with a slow 3.8 N/A.

Wow, odd we missed the post originally. Glad you got it figured out. Tahnks for sharing the cause.