96 318is M44 Overheats

This car drives well although the idle seems a little low (slightly rough idle when warm).

Yesterday after about 30 minutes of heavy traffic it went into overheat and blew a heater hose.

The drivers manual says its normal to get near the red zone when experiencing long idle periods but I was wandering if anyone new of a way to keep this M44 cool?

Water pump is less than two years old. Coolant is green and fresh; water pump is upgraded with plastic housing but metal impeller. Serpentine belt is new and tight.

Any suggestions would be greatly appreciated.

Radiator

Make sure the mechanical fan is doing it's job and moving sufficient air after warming up. I would also look into a radiator as well. They can gum up over time and slow coolant flow, thus causing a overheat condition. Anyone else have any thoughts??

If the temp is fine when moving, but then overheats or climbs when stopped, it's probably the fan clutch. An easy test: When the motor is at normal operating temp, take a rolled up newspaper and gently try to touch it against the fan. If the fan shreds the paper, it is ok. If the fan slows or can be stopped, the clutch is gone and it should be replaced. #11-52-1-466-000 at Pelican for $68 US. You might need to get the 32mm specialty wrench to pull that off if you don't have one.

Thanks for replying guys but the mechanical fan on this model was suggested to be remove (and it is) by the factory. They suggest using a large electric fan which it has.

The radiator, water pump and thermostat are less than two years old.

Hoses appear to be in good condition and there is no coolant leaks.

Thanks

Does the electric fan come on? You can force it to come on by jumping out the switch. Test for working low and high speeds on the fan by doing so.

I finally decided to turn it over to a mechanic.

Thanks for the replies.

overheating

Agree with Mooseheadm5, its easy to test the fan. I had to replace mine. It went out on low speed.
I lost a heater hose at the air intake and fried the head gasket. I just now, after five weeks am back to having the 318 back on the road. What a lesson for me, and yes, I did my own wrenching.

Mike

What was the outcome?