Overheating At Idle - BMW Forum

BImmerN2B · 07-24-2005, 08:34 AM

Hey guys, I have a 318i 5 speed. My car overheats at idle at about 3 min or so of idling without the AC. With the AC on, it would run fine all day. I changed the temperature switch and its still the same. I try to look for this topic and in some places they say it could be a resistor at the Electric fan. Is this something that can be changed or do I have to buy a new fan?

Or what else you guys think it could be?

Bear · 07-24-2005, 01:48 PM

Fan Clutch, not the aux fan.

BImmerN2B · 07-24-2005, 02:45 PM

I thought that my fan was electrical. there shouldn't be a fan clutch

Bear · 07-24-2005, 02:58 PM

You have two fans, the one you can see in the engine compartment that attaches to the water pump pulley (the viscous fan) and an electric one that is in front of the radiator. If she overheats at idle, odds are it is the fan clutch on the water pump pulley fan. If the electric fan runs with AC on (and it should) then the resistor is good.

BImmerN2B · 07-24-2005, 09:01 PM

I checked about a fan clutch, but I shoudn't have such a thing. I checked my manual and personally my car and it's an electric fan.

Bear · 07-24-2005, 09:07 PM

When you open the hood on your car, do you see a fan on the front of the engine?" If yes that is the vscous fan with clutch (the aluminum casting in thecenter of the fan blades either on front or rear of the fan is the clutch) Now, look throught them kidney shaped grill and you will see the electric (auxiliary) fan.

All of our cars have two fans and if the viscous one goes bad, the engine overheats at idle. The electric fan comes on anytime the AC is selected and also has two speeds (low and high) that are triggered by one or two fan switch/es that on your car is/are probably located on bottom, back side of the radiator.

BImmerN2B · 07-24-2005, 10:14 PM

Thanks for the info Bear. Unfortunately, alll I see is the one in front of the engine. It is not attached to the water pump pulley. In my manual (Yes is the suckey Hanes Manual) says for the M44 it has an electric fan. Could it be that they have a fan clutch too? I thought fans attached to the water pulley had a fan clutch only.

The other issue is I think I got Fucked on the Auxiliary fan, There is no fucking fan there!!!!

ghead maybe a dumb ass question, but could that be it. doesn't it come on at Idle?

RallyE36 · 07-24-2005, 11:47 PM

Have you checked the thermostat or replaced it?
It comes as a single unit with the housing and hose connectors.

drz · 07-25-2005, 12:39 AM

Thermostat, air pockets, or lose drive belt. Works fine with the AC on because that turns on the auxiliary fan that I will boldly say you do (or at least should) have.

You are right. You don't have a fan clutch problem. M44 e36s and a manual transmission have an electric cooling fan instead of the belt-driven viscous fan. All e36s have a two-speed electric auxiliary cooling fan mounted behind the front grille and in front of the radiator. If you don't have an auxiliary fan, somebody took it out.

Bear · 07-25-2005, 08:04 AM

Now I am really confused as all parts data bases show a fan coupling (looks like a clutch) for this car. Try www.realoem.com/bmw/select.do then do your car, year, and at search for parts go to engine and then cooling and see if a fan clutch does not appear.

BImmerN2B · 07-25-2005, 03:16 PM

Well, I'll be I don't have an auxiliary cooling fan. Before in place of it was a fucking neon. I bet they took it out so they could put a silly neon bar in the car.
I will still check the other stuff. Although my belts were changed, new thermo was put in and a flush was done by the stealer. although is funny because I put the A/C on and it's good, but I turn off and that needle will go to RED.

drz · 07-25-2005, 03:53 PM

That is really weird. Try to get an aux fan. They are expensive, though. Maybe they wired the primary electrical fan to work on high speed when the AC is on. Just keep the AC on, I guess.