New here and my 1989 240SX is overheating when it idles

[mmrodri]

Hey all,

I'm new here and have been looking for an answer, but nothing I've seen around so far seems like it's a great match for what I'm experiencing.

I've had my '89 240sx for about 5 years now and over the course of time a few random things have popped up that didn't affect the driveability of the car (Cruise stopped working, headlights stopped going down, and the radio sometimes cuts in and out [probably just a loose connection]) so I generally ignored them.

More recently, I've noticed that the engine will overheat when the car idles, AC is on, etc., but when I drive above about 35 mph, it's totally fine. The problem doesn't start until the car has been driving for about 10 minutes--after that it overheats very fast if the car is not constantly above ~35mph.

On one hand, it feels like I'm living out the movie Speed, but on the other hand, I live in Southern California and need to be able to run my air conditioning and be stuck in traffic without worrying that my car is about to go nuclear.

My wife isn't very much a fan of having a 25 year old car which she has long since deemed "unreliable" but if I can get it back to full working condition without blowing a huge wad of cash, that'd be ideal because I love the way this car handles for me.

Thoughts? Suggestions? Any help is appreciated.

[Razi]

Hopefully it's not a blown headgasket. Take a look at the oil dipstick and see if your oil looks like milk chocolate.

If it's not, you probably just need to bleed the cooling system.
I'd try to raise the front up a bit (like put it on jackstands or just sitting on a driveway) to help get some of the trapped air move itself forward.
From there you can fill it up at the radiator, then later open up the bleeder screw on the upper coolant neck and keep pouring in water at the radiator until bubble free coolant pours out of the bleeder hole.

[DaniMike]

Welcome! First make sure your auxilary fan works. I alread had new radiator and used stock clutch fan with shroud, my car had the same symptoms. Swapped out auxilary fan and all has been well since.

[OddyseusDSM]

Fan clutch is probably going too

[PapaSmurf2k3]

+1 for checking the fans. After that check to make sure your actual coolant level is correct. Finally, if that is all good, your water pump might be on its way out (and only works well enough to circulate coolant at higher RPM).

Let us know what you find out!