1996 BMW 328i overheat light went on on highway. Pulled over. Engine was super hot, but radiator was fine. Steam coming from oil cap when I removed it. Radiator was not hot, I opended it and it was fine. Fans were not running. Had car towed. Any advice?

A NEW RECORD FOR LONGEST 1ST POST.
2004 Camry XLE 4 cylinder 207 thousand miles
guess at 2.4L engine. but there are 3 engines offered.
2AZ-FE ENGINE SURE.
THAT OVERHEATS,
LET ME CONDENSE YOUR POST.
1: NEW LEAKING CAB HEATER CORE.
And sure after it stinks how can it not 50%AF toxic fluid in the passengers foot well carpets. gee get them steam cleaned by pro's (removed and pro cleaned)(

2 :now the coolant is leaking and spraying in the engine bay well that is normal on all cars this old (not serviced, abused)
all hoses bad and 19 years old cracked and leak what's new there, zero..nada.

or water pump leaks
or radiator leaks, sure, 19 years old sure it can.
nothing new there.
what will be ,will be. there is no magic to car repair
--------------------- NOW COMMENTARY BLIND------------
best guess:
he used bar's leaks to stop tiny leaks. that is all it does
it never ever fixed cracked hoses ,bad water pumps nor fixes radiator leaks. or bad head gaskets or warped heads.

if he was a pro he;d have told you the car needs major service, and parts but when told by him, the wallet was dry
outcomes snake oil BAR's leaks.
fix it right or patch it and pray. <<<< your CALL !

BAR'S: (MAKERS REAL NAME)
it can help some times in pinch 1000 miles from home
it's a band-Aid to a broken leg. ( not magic, it is a desperate act)<, NO BLAME ME IT IS YOUR CAR.

old cars are all like this they have vast problems and most ive seen 10 problems ignored by the owner.past and present. (all) they add up, and then the camels back is broken with 1 more gain if straw.!
machines need service, if not they fail or fail hard.

if the engine is allowed to overheat too badly the engine is wrecked, ever price out cracked heads and engine blocks.
some cars heater cores are $2000 fix, dash out 12hours labor.+parts.
seems to me you got a SUPER DEAL there.
MY GUESS JUST HEATER COR HOSES BAD
AND ARE THE HOTTEST HOSES AND WHY.

Each leak must be found and if hoses crack they are all bad, for sure if 19 years old.
the RAD tank ends can crack TOO.
and the pump fail and the path of the whole coolant loop can fail and crack a real pro finds them all.
even intake manifolds can leak or thermostat housing can crack, SEE????????
TOYOTA Camry 04
lot to fail on any cooling system
even rad fans.
WE CHECK AND CURE ALL LEAKS FIRST
UNDER FULL HOT ENGINE PRESSURE,NEAR 15PSI
FOR LEAKS, PARKED HOOD UP EVEN RUN FOR 30 MINUTES TO FIND THEM ALL
CAREFUL AND COMPLETE OBSERVATION,
FOR SURE DRIPS OR TRICKY SQUIRTING OF 50%AF COOLANT.
NO 19YEAR OLD THERMOSTAT IS GOOD
AND IF BAD AND CAUSES OVERHEATING THE SIDE TANK NEXT TO RAD EXPLODES IN STEAM AND IS SUPER BAD FOR ANY ENGINE (JUST BEGGING TO WARP THE HEAD)
AND A NEW SERP BELT TO THE PUMP IS BEST.
THIS OLD.

Hope this helps, do this VERY Careful, when over heating Turn ON the heater to full, does it cool down? does the water in the Radiator Boiling?. = water pump, (don't always make noise).
Not boiling?- Check and R&R Heat sending Unit Gage on the Radiator or somewhere on the engine maybe close to the Thermostat..

I would replace the radiator cap and then recheck for overheat

you need to have the system check for pressure-it should be about 17psi -if it goes higher you have a blown head gasket which is blowing the coolant out of the system-or you might just have a radiator cap which is failing to hold pressure-up to 17psi- also youmay not be getting all the air out of the system and have an air pocket which will get super hot and steam the antifreeze- have the system vacummed down and the antifreeze will be sucked back into the system eleminating the air pockets-so you have a few things to look here-Ihopr this helps-Denny

My guess is that your electric fan is NOT operating at all. Under normal conditions, just going down the highway, your cooling system will function just fine without a fan running. The air flow through the radiator is adequate to keep things cool. However, when you stop, you quickly get into an "overheat" situation. Actually, you should be able to hear your fan begin operating when your engine temperature starts climbing or your air conditioner requires the fan to do its thing. Note: If you've ever severely overheated your engine, your problems may be worse than just a fan not running, but you really do need to confirm whether your fan is operating correctly, or not. Another note: I had a vehicle with a tendency to overheat when stopped. It turned out to be a faulty (leaking) pressure cap on the cooling system.

You cant just flush the core, youre going to have to flush the whole system. There is a kit but i recommend going to a lube shop. Another cause could be the radiator cap.

Most likely a bad Thermostat or Water Pump. Replace the Thermostat, the cheapest part, and if it still overheats replace the water pump.

From your description of symtoms it sounds like you have a bad water pump. If the coolant is not circulating properly you will have a heating problem. Sometimes even a new thermostat can stick and cause the engine to overheat. I have seen them fail in as little as a week after they were installed.

I had the same problem, whole new radiator, new hoses, new thermostat, and still overheating. What the problem was for me...bad radiator cap...all that money and a $20 fix...try it?

Make sure the electric radiator fan is coming on watch it while it's running for about ten minutes if it doeasn't come on in that time replace the fan relay or fan itself if the relay doesn't fix the problem.