Fan 'delete'

[Ali77]

Fan delete completed over the weekend. I am very lucky that my Daughter has a partner who is an excellent mechanic and enjoys working on the Z3. Any references to "we" really mean "he, and I passed the spanners". Thought it may be of interest to share some pictures and words with anybody else thinking of doing this modification.

The parts:

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Wahle thermostat (11531437040 from E-Bay - Motormec) and Gates aux belt (5PK908 from Amazon -SparesHQ).

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Meyle water pump with metal impeller (313 011 2001 from Amazon), Valeo Service Thermo switch (820319 from Amazon) and Gates main belt (6PK1540 from Amazon). If the belts do not come up on an Amazon search try typing the reference into Google and it may throw up a link to the Amazon page (this is what happened for me).

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First challenge was the head dropping off the radiator bleed screw as soon as it was touched. The head had been broken off, a cross head screw put into the stump and the head put back on with sealer. Fortunately we had bought a new plug
(17.11.1.719.384 from local BMW dealer) before starting. Made me wonder when the coolant was last actually changed (I paid for it to be done by a local German car indy "of good repute" when I bought the car 2 years ago)!!

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Main belt looking tired at 86,000 miles.

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Aux belt looking very tired.

The removal method basically followed the description in this article http://www.zroadster.net/forum/viewtopic.php?
f=18&t=3631. No special tools used to remove the viscous fan though we shocked it off with a big hammer (would not recommend if you are not changing the water pump).

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We also needed to replace the seals on the A/C condenser so that came out as well. Perhaps as well considering the accumulation of muck and flies.View attachment 21060

With the front end stripped out access to do the job was easy.

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Old thermostat with broken retaining lugs, which explains why the engine never reach full temperature.

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New unit with the later style support legs.

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Water pumps, old and new. The central hole on each side is threaded (M6). A bolt each in each is used to jack the pump out of the housing.

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Nice new belts fitted. Hopefully good for another 80,000 miles.


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Old and new temperature switches. Note the difference in the lower horizontal flat section. The old (lighter) switch has a keyway to the right hand side the new one has it to the left. This presumably was to detect if the wrong switch had been installed during manufacture. The radiator was made by Valeo so this feature may not be present on non OEM parts.

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The plug where you can see the guide that goes into the keyway next to the "1-" marking. This has to be trimmed off for the plug to fit.

When it was all back together the coolant was refilled, see https://zroadster.org/threads/anti-freeze-which-colour.9093/#post-133977 for more information.

On start up the engine reached operating temperature quickly and the needle was rock steady in the central position. When stationary with increased rpm the electric fan switched in and putting the heater on full blast caused it to turn off, so all seems to be working as expected.

If you are thinking of doing the same job I hope you find the write up of help.

I’ve got all that too, never had a problem on road for years now, but track driving is another story!

If I wasn’t tracking it I wouldn’t bother. Even standing in queues of traffic on hot days the aux fan only works fine.

I’ve just noticed when I used the number you put up for the new thermostat that it’s using the thermostat that opens at 97 degrees. If this is the case then is that why you still run hot on track days?

 

[Broad Ambition]

I've recently done a 'Fan Delete' along with installation of an electric fan to replace it. Details / photo's over on my Zebedee thread

Griff

 

[Ali77]

I've recently done a 'Fan Delete' along with installation of an electric fan to replace it. Details / photo's over on my Zebedee thread

Griff

Hi there fella, what thermostat and housing did you use? I’ve ordered 3 now and all have turned up and turned out to be wrong

 

[Broad Ambition]

I used an in line variable thermostat - Cut 20mm out of the top hose and fitted it there. Then let the engine idle until the temp guage was just above where it normally sits, then set the thermostat to switch the fan on. Works a treat and under normal / spirited driving the electric fan is redundant on pulling up the fan is not running and temp is at normal on the gauge with forward motion progress air entering the rad being sufficient to keep the coolant at 'Normal'

Hope this helps

Have a look-see on my Zebedee thread for photo's

Griff

 

[Ali77]

I used an in line variable thermostat - Cut 20mm out of the top hose and fitted it there. Then let the engine idle until the temp guage was just above where it normally sits, then set the thermostat to switch the fan on. Works a treat and under normal / spirited driving the electric fan is redundant on pulling up the fan is not running and temp is at normal on the gauge with forward motion progress air entering the rad being sufficient to keep the coolant at 'Normal'

Hope this helps

Have a look-see on my Zebedee thread for photo's

Griff

Not gonna lie, you’ve completely lost me there! I was under the impression that I could simply buy a set up to like for like replace the old thermostat and housing

 

[Rudyrov]

What methods are available for auxiliary fan control? I had been using a dash-mounted switch but this proved to be a hassle, what are you guys using out there?

 

[Ali77]

Here the list of parts I’ve bought but the thermostat didn’t fit in the housing correctly if someone could point me in the right direction..
thermostat housing 11531722531
80 degree fan switch ts2708
Water pump hep-p472
Thermostat 80 degree 11531710953
1 bottle of water wetter

 

[Rudyrov]

I decided to try a radiator push-through-switch, temp 180-165. I'll report back once I get it and install it. https://www.amazon.com/American-Vol...14-ed3e5c86abe2&ref_=pd_gw_ci_mcx_mr_hp_atf_m

 

[Andyboy]

I've yet to work out what's wrong with a standard viscous fan. It's idle 98% of the time and only locks up when the engine is hot.

 

[Ali77]

I've yet to work out what's wrong with a standard viscous fan. It's idle 98% of the time and only locks up when the engine is hot.

Mine was on 90% of the time fella and it sounded like a hovercraft. It was only a matter of time until it snapped and went through the radiator

 

[Andyboy]

Replace the coupling?

 

[Ali77]

Replace the coupling?

I did think about it, but the horror stories you hear about when they let go just made me think I’d sooner delete it, although tracking down the right parts has been a bloody nightmare. With hindsight I would of just replaced the coupling.. but I’m in too deep now

 

[Broad Ambition]

Mine was on 90% of the time fella and it sounded like a hovercraft. It was only a matter of time until it snapped and went through the radiator

Mine was running right from start up and sounded like the same hovercraft you were hearing - Thankfully no more

Griff

 

[Ali77]

Mine was running right from start up and sounded like the same hovercraft you were hearing - Thankfully no more

Griff

Did you delete the fan or replace the coupling if you don’t mind me asking fella?

 

[Broad Ambition]

Don't mind you asking at all, I took the fan / coupling / cowling out altogether and replaced them with a 12v dc electric fan.

You can find the details with photo's here:-

(1) Zebedee - It Begins! | BMW Z1 Z4 Z8 Z3 Forum and Technical Database - ZRoadster.org

Hope that helps,

Griff