Viscous to elec fan change

[Doomsdaya]

Sorry to hear about your viscous fan imploding GP, is your car an auto or manual ?

 

[Gizmo]

If your e46 320i is manual then what is it doing with a viscous fan? You need the 6cyl electric fan.

 

[GPGrobler]

Gizmo, are the 4 cyl and 6 cyl fans different from one another? G-Drive stocks a fan for all petrol models, so is the fan not the same for all the E46's?

 

[Gizmo]

There is a difference yes.

 

[Doomsdaya]

So I finally got a chance to test my car this weekend and it does make a difference in economy, usually I would get 250km from full tank to 3/4 averaging 130/140km/h. This time I got 280km and in gear acceleration is much quicker....

 

[GPGrobler]

How does the fan cool the car? Any signs of temperature problems with the electric fan?

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There is a difference yes.

So then who should I buy the fan from? G-Drive?

 

[Gizmo]

I have a brand new one here for 6cyl. Never used. Gimme R2400 for it.

 

[GPGrobler]

Hi Gizmo,
I found this loose plug after the viscous fan destroyed itself an the fan cowling, is this the plug for the electric fan?

 

[Gizmo]

what colour and thickness are the wires?

 

[GPGrobler]

Another pic:

 

[Major]

I have not had issues with viscous delete and the 92deg thermostat still in place and the 80/88 switch running the aux fan, no extra fans needed, even on a M3 door.
Guys in Texas will fit an extra electric fan if they track their cars.

This may be a stupid question, but if you keep your 92 thermostat why have an 80/88 switch? The switch will only see something below/around 92 degrees, so it'll be full speed or nothing since water won't start flowing through the radiator below 92 on the hot side. The standard switch is 91/99 (on a 328i at least), so they obviously want the engine in or near that range.

 

[GPGrobler]

Hi,

Thick red and brown wires 3mm thick, about (30 amp load) and one 1.5mm green and black wire.

 

[Doomsdaya]

Yesterday I unexpectedly got to test the car in bumper to bumper traffic on the M1 south highway, sat for over an hour and temp gauge was dead center, did not move at all. Also in the process, I didn't end up wasting fuel, despite sitting in traffic and with a combination of high speed driving, I got excellent consumption....

 

[Sankekur]

I have not had issues with viscous delete and the 92deg thermostat still in place and the 80/88 switch running the aux fan, no extra fans needed, even on a M3 door.
Guys in Texas will fit an extra electric fan if they track their cars.

This may be a stupid question, but if you keep your 92 thermostat why have an 80/88 switch? The switch will only see something below/around 92 degrees, so it'll be full speed or nothing since water won't start flowing through the radiator below 92 on the hot side. The standard switch is 91/99 (on a 328i at least), so they obviously want the engine in or near that range.

Because the 92 degrees of the thermostat is the temperature at which water will start being circulated through the radiator. The fan switch is on the other end of the radiator where the temperature is lower, if however for lack of airflow through the radiator the temperature on the cold side rises above 80 degrees it will turn the fan on to try and remedy this, if it is unable it will turn the fan on at the higher speed when the temperature at the switch reaches 88 degrees. So it is not a discrete matter of thermostat opens and the radiator is at 92 degrees, this heat first has to propagate though the radiator.

 

[Gizmo]

I have not had issues with viscous delete and the 92deg thermostat still in place and the 80/88 switch running the aux fan, no extra fans needed, even on a M3 door.
Guys in Texas will fit an extra electric fan if they track their cars.

This may be a stupid question, but if you keep your 92 thermostat why have an 80/88 switch? The switch will only see something below/around 92 degrees, so it'll be full speed or nothing since water won't start flowing through the radiator below 92 on the hot side. The standard switch is 91/99 (on a 328i at least), so they obviously want the engine in or near that range.

Its a case of applying the same setup the 318is uses to other e36's. The 318is uses a 95deg thermostat yet has the 80/88deg thermostat switch from the factory. Years ago when I first started doing these fan delete conversions I experimented with different temp fan switches and thermostats, starting off with just removing the viscous fan and keeping the original 91/99deg fan switch in place, I found when sitting in traffic that the heat gauge would climb past the halfway point before the electric fan would switch on. After switching out the fan switch for the 80/88 one the gauge would stay in the centre.

Now as far as the thermostat goes, the original fan delete mod calls for a 80deg thermostat to replace the 92deg one, although it works fine and the gauge stays centre irrespective what temp thermostat you using. I prefer keeping the original 92deg thermostat in place as the hotter engine will get a better fuel atomisation ie better fuel economy. Paranoid guys prefer to swap out the thermostat for the 80deg one but I find it is not needed and perhaps overkill. If we had a hotter climate then the 80deg thermostat would probably be needed.

 

[Major]

Alright, that clears it up, thanks guys. I saw most FDM's using 80 degree thermostats so that the fan had more of a buffer in which to work, or so they put it. Your engine will get up to whatever temperature the load and cooling abilities demand anyway.

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Are you guys doing anything differently in terms of the fan shroud when using an aux fan?

 

[Gizmo]

The fan shroud stays in place as its the mounting point for the expansion bottle.

 

[GPGrobler]

If you put the 80deg thermostat, will the engine run a bit cooler? I'm asking because my E30 performs at its best below the hafway mark, about 1/4 on the temp guage. Also we get many days here in the high 30's so the cooler thermostat might be essential in this part of the country.

 

[Sankekur]

Yes

 

[Gizmo]

The E30 325i uses a 80deg thermostat already.