Car overheated right after I got off the freeway?

[E30_Narek]

x bajillion on the fan clutch, I'd also check the shroud and blade for cracks while they are off, also, I'd put in a new thermostat and coolant mix at the same time.

No need for a new thermostat or coolant. I put in a new thermostat a little over a month ago and along with a whole coolant flush + blue BMW coolant.

[Farbin Kaiber]

x bajillion on the fan clutch, I'd also check the shroud and blade for cracks while they are off, also, I'd put in a new thermostat and coolant mix at the same time.

[E30_Narek]

The electric fan will not help keep it cooler than a functioning fan clutch.

Your temps vary because you have a non original thermostat in the car or a faulty one. The way the stock setup (properly functioning) works is that the thermostat opens just below the halfway mark on the gauge and the fan clutch turns on right about at the middle of the gauge. This gives you a very stable needle because if extra cooling happens (highway speed airflow) the thermo closes and keeps the temp up and if the temp starts to climb , the fan engages more and and keeps the temp down. If you put a colder thermostat in, highway speed airflow will drop the temp to the thermo close point which might be the first line and so your gauge will move up and down as you describe.

A faulty thermostat (not flowing properly) will keep the fan clutch from engaging at all since the fan is turned on by the radiator heat.

To test the fan clutch, get the engine hot and stick a rolled up newspaper into the fan. If you can stop it, it is not engaging.

Even when my cooling system was stock, my temperature gauge was still unstable. Every 20 or so miles I drove, the needle went above halfway, then after a while returned to half then went down to below half, and repeated over and over.

EDIT: I've come to the conclusion that my brass nut is loose. My temperature gauge wiggles and fluctuates from time to time so I'm assuming the nut is loose. Every time I tap/slap my dash around the temp gauge area, it jumps or moves.

[Cephas]

The erratic temp gauge could also be a loose brass nut on the back of the cluster.

[Navarone]

In the original post, second to last line, first 6 words...

Yup, that's exactly what and where I missed.

[glnr13]

In the original post, second to last line, first 6 words...

I don't lose/leak any coolant...

[Navarone]

actually I meant you. You should check your system since you're losing coolant.

OP's problem is most likely fan clutch as others have mentioned + he is not losing coolant.

I keep it topped up, too lazy and broke to chase down a tiny leak.

I must have missed it where he said he wasn't missing coolant.

[glnr13]

Yeah it's something he should check.

actually I meant you. You should check your system since you're losing coolant.
OP's problem is most likely fan clutch as others have mentioned + he is not losing coolant.

[Navarone]

This is true in regards to fluctuation of the temp gauge in the cluster but more importantly, if your coolant level is going down you have a leak somewhere. Coolant level should not go down at all.

Yeah it's something he should check.

[glnr13]

My temp goes from 1/4 to 1/2 depending on weather and driving style. Also check your coolant level, mine fluctuates more as the coolant goes down.

This is true in regards to fluctuation of the temp gauge in the cluster but more importantly, if your coolant level is going down you have a leak somewhere. Coolant level should not go down at all.

[LJ851]

Hehe, and I was gonna quote you before to thank you for all that great info. Now I'll just thank you for the lols.

I do want i can. ;)

[jbgood]

OP --
The biggest benefit to posting questions on a forum like this is to solicit the opinion of others who have been through similar situations. These guys are trying to explain that a properly functioning stock cooling system (fan clutch, thermostat, no leaks, etc...) will more than handle your situation. The symptoms you describe point toward several issues in your cooling system.

Starting with an electric fan may very well waste your time and money, as well as continue to place your engine in jeopardy. That being said, good luck with your troubleshooting.

[Navarone]

Fixed.

Hehe, and I was gonna quote you before to thank you for all that great info. Now I'll just thank you for the lols.

[LJ851]

My temp goes from 1/4 to 1/2 depending on weather and driving style. Also check your coolant level, mine fluctuates more because i have a shitty cooling system that leaks.

Fixed.

[Navarone]

Car overheated right after I got off the freeway?

The dude is "technically" correct. The transmission should get warmer after a spirited drive, but this small increase in temp should not contribute to the OP's problem.

Yeah I didn't mean to imply that it was the sole cause of his symptoms, just that the temp will spike after driving hard then stopping abruptly without a cool down period. My temp goes from 1/4 to 1/2 depending on weather and driving style. Also check your coolant level, mine fluctuates more as the coolant goes down.