What can cause an BMW 320 to over heat ??

chaparral · 29 Sep 2011 at 23:01

Someone i work with has an old BMW 320 that keeps overheating (even when idiling)

It had a new rad ,new rad fan and thermostat fitted
and there don't meant to be any heat gasket leaks and no looses any water..

What else could be causing it to over heat ??

The_Abyss · 29 Sep 2011 at 23:02

Stupidly high ambient seasonal temperatures?

shoes · 29 Sep 2011 at 23:04

Excessive heat

Matt82 · 29 Sep 2011 at 23:05

insufficent cooling

chaparral · 29 Sep 2011 at 23:06

The_Abyss said:
Stupidly high ambient seasonal temperatures?

shoes said:
Excessive heat

The weather hot but not that hot

chaparral · 29 Sep 2011 at 23:07

Matt82 said:
insufficent cooling

Has brandnew Radiator and fan....so there should be sufficent cooling

Jonny ///M · 29 Sep 2011 at 23:12

chaparral said:
Has brandnew Radiator and fan....so there should be sufficent cooling

Not unless it wasn't fitted properly I'd say.

Will Gill · 29 Sep 2011 at 23:14

I heard poor grammar is a big cause

Dabbles · 29 Sep 2011 at 23:15

Water pump?

Mickie · 29 Sep 2011 at 23:18

Will Gill said:
I heard poor grammar is a big cause

your mam

normally a water pump or thermostat isnt it

Rich1988 · 29 Sep 2011 at 23:19

air lock, if its just had a new rad

Raymond Lin · 29 Sep 2011 at 23:20

28c isn't hot though. It's mild in some countries.

chaparral · 29 Sep 2011 at 23:23

I wondering if it worth checking for low oil pressure and if this could cause it

Rich1988 said:
air lock, if its just had a new rad

Could be....

I didn't fit the Radiator,the local BMW dealer did..

paradigm · 29 Sep 2011 at 23:25

The entire cooling system is a crock of ****, the e36 and e46 are a pain to bleed correctly, so first port of call would be to drain and re-fill the system with known correct coolant, and bled properly.

Possible thermostat failure, so take that out (10-15 minute job max), and test in a pot of near-boiling water (opening temp is 88 degrees celcius).

Other than that, it could be a pump, but they aren't quite as common a failure point as the radiators, thermostats, and bleeding issues.

Mickie · 29 Sep 2011 at 23:25

chaparral said:
I wondering if it worth checking for low oil pressure and if this could cause it

go back to sleep

chaparral · 29 Sep 2011 at 23:28

Mickie said:
go back to sleep

My old vauxhall calibra suffers low oil pressure when hot and over heats because of it

Mickie · 29 Sep 2011 at 23:39

obviously oil will thin when hot but i dont understand why the engine would over heat as its cooled with water, not oil.. if the oil gets too hot i dont quite understand how that would then overheat the water, as thats regulated by the thermostat, if the oils getting too hot, buy an oil cooler..

chaparral · 29 Sep 2011 at 23:57

Am guessing there maybe more fiction when the oil pressure drops...But then again if there was that much fiction then surely the engine would seize

But i have read about people that have increased the oil pressure and it has made the engine run cooler..

Rich_L · 30 Sep 2011 at 00:35

I'd go with air being stuck in the system especially if it's overheating even at idle - after I replaced the water pump on my car I found that parking it up hill and giving it some revs with the cap off the header tank and then giving the cooling tubes a few squeezes helped get most of the air out.

Fuzz · 30 Sep 2011 at 08:18

Replace water pump and bleed through again.

As said, these can be an utter **** to fill properly.

Expansion tank if it's a e46 is another favourite (needs to be OEM)