That fancy redesigned fan and fan clutch.......

[Gregory891]

@ civdiv99. Very good way to do this and I do agree, I've done this on an older BMW (gasoline) that was pre-catalytic. The only (potential) issue with a modern EFI gasoline car with lowering the temp is fault codes (very modern) and long time for cat to warm up.

I'd consider on my X5 but as a diesel, you need a modestly higher temperature to ensure condensation and the (modest now with modern lower sulfur fuels) formation of sulfuric acid. The diesel E53 have a lower cooling system pressure (which is where many gas E53 owners source their lower pressure expansion tank cap).

For those with the M57 in their E53, I'll be trying this later this summer an d will report back.

[civdiv99]

Mine acts 100% normal up until the engine reaches my designated operating temp. The circuit allows me to adjust not only set point, but also slope. Since the engine runs within the designated range, it's happy. No codes. I have a dummy load incorporated to keep the factory thermostat heater circuit happy. ; I don't modify the factory signal, I completely replace it.

Originally Posted by Gregory891

@ civdiv99. Very good way to do this and I do agree, I've done this on an older BMW (gasoline) that was pre-catalytic. The only (potential) issue with a modern EFI gasoline car with lowering the temp is fault codes (very modern) and long time for cat to warm up.

I'd consider on my X5 but as a diesel, you need a modestly higher temperature to ensure condensation and the (modest now with modern lower sulfur fuels) formation of sulfuric acid. The diesel E53 have a lower cooling system pressure (which is where many gas E53 owners source their lower pressure expansion tank cap).

For those with the M57 in their E53, I'll be trying this later this summer an d will report back.

[srmmmm]

Originally Posted by Gregory891

@ civdiv99. The only (potential) issue with a modern EFI gasoline car with lowering the temp is fault codes (very modern) and long time for cat to warm up.

The higher operating temperature will reduce the mayo build-up in the CCV system.

2002 X5 3.0 280,900 miles
2004 325i 120,600 miles

[civdiv99]

Agreed. I'm willing to go with it though. Pretty dry climate here.

Originally Posted by srmmmm

The higher operating temperature will reduce the mayo build-up in the CCV system.

2002 X5 3.0 280,900 miles
2004 325i 120,600 miles

[Clockwork]

the nut holding the fan clutch to engine is also known as a 32mm size wrench. I just had to buy one for my 8 to remove the clutch. OH and remember its a reverse thread.

[bcredliner]

Some say to put the wrench on and whack it with a big hammer. I don't do that because I feel that is risking damaging the water pump. Some try with a regular open end wrench. You can get it on there but it will be too thick to get the second wrench in place. I've tried everything in my toolboxes to use as the second wrench to no avail. I suggest to bite the bullet and purchase the special wrench set to loosen the bolt. Very difficult to do it any other way. Several options are available on eBay. Unfortunately, it's one of those special wrenches you many never use again. Maybe somebody you know has the tool or might be a place to rent one. BMW 32mm Fan Clutch Wrench Water Pump Holder Removal Tool | eBay

[civdiv99]

Originally Posted by trader4

I've done it several times using a 1 1/4" open end wrench.
It isn't too thick, it goes right on. I used a long screwdriver to
lock against the pulley bolts to hold against it. A light whack with a
hammer, it came right off. Once cracked loose, it spins right off.
You do want the belt on when you're doing it, as it helps keep
it from turning. The special tool I'm sure makes it easier and
might even be essential if it's really frozen on there.

I've been using the 1 1/4 (shown in the pic at beginning of this thread) for years. As noted, drops right onto the nut, thwack once or twice, and spin off. I bet I took longer to retrieve the wrench from the tool box than to remove the fan and clutch assy.

[Joshdub]

I had a fan that was put on with loctite. That was fun getting off. Even with the right tools it was a bear. You can get the wrench and water pump holder for about $20 shipped on ebay. Well worth it in my opinion.

[Doru]

A "frozen" fan clutch nut can be loosened with an air tool as well. I had one seized, and used this approach (fan tool didn't work, short sharp hit with hammer didn't work). Had the 32 open end wrench on the stubborn nut, and used an air hammer with a blunt chisel on it. Same approach as using the impact wrench.