Alright everybody, so this is my first post and coincidentally also my first Acura. I am having major overheating issues. Car is completely fine in town. Can drive all day long without the temp rising at all. After driving interstate speeds for 30mins or longer and then slowing down to 25mph or below the overheating begins. I have no clue what it could be. Just got an oil change. Flushed and burped the radiator. Replaced the thermostat twice. Both fans seem to run when AC is on not sure if they are running when driving though. Any ideas?

 

Does it happen when the ac is off only?

 

Normally after I slow down it starts to rise above normal but not quite red lined, but if I turn off the AC it red lines. If I then turn the AC back on it drops a little but then a burning smell fills the cabin. Some think I blew my head gasket but there is no coolant or water in the oil, car is not lacking in power at all, and there is absolutely no white smoke coming from the exhaust. I am baffled

 

Where do you live?

Maybe a clogged radiator if the head gasket is still good? Bad radiator cap? Hard to diagnose over the Internet, you might want to go to a good local mechanic.

 

I live in Fort Hood, Texas. Radiator cap seems secure but I will attempt to replace. All the mechanics around here charge an arm and a leg just to diagnose. Cheapest I was quoted was $80 just to diagnose. Unfortunately my budget does not allow for an $80 expense lol. I'm thinking possibly the fan is not working when driving. Guy at Oriellys said something bout a coolant temp switch but from everything I've read doesn't seem to be the culprit

 

Your thermostat could be malfunctioning.

I always start there because the part is anywhere between 8-15$.
You might end up with some coolant on the drive though...

There's plenty of videos on youtube that detail that.
My guess is that you're not getting coolant flowing through the engine because the thermostat is stopped up. They expand and contract based on temp. to provide the engine the proper temp control. That's why yours starts to overheat after a given time. The A/C helps keep it cooler by blasting the front of the car with cooler air.

Ease of change: 4/10
Time: 45min - 1.5 hours

Pro-tip: don't over or undertighten your thermostat housing. Make sure to do that to spec, or you'll be using a lot more coolant than you'd like.