This should explain how the aux fan works whether it's working properly or not:
- How to test the cooling system auxiliary electrical aux fan (1) (2) (3) (4)

 

I'd rather just have someone answer the question. Thanks.

 

No problem. Good luck!

 

So, which is the proper behavior?
The fan never staying on after you park,
or the fan always still running after you park?

Neither - the fan may run after shutting the car off, usually when it's very hot.

 

I am uncertain of the "proper" operation, but I've never heard the fan continue to run after shutdown, even on the hottest days....I'm talking 100F +. I would be surprised if it did. Most cars, including motorcycles, the fan is controlled by the ignition switch. With the key out, the fan will not continue to operate. Fan operation after shutdown is not very useful...while it will cool the water in the radiator, it does little to cool the engine, since that water is not moving, as the water pump is engine driven, off the accessory drive belt.

I wouldn't be concerned if it did, it is not going to run very long, regardless, to drop to the cut off point and turn off.

 

Honda's run for up to 15 min after shut down

But this is not a Honda

Sticky relay ?
Bad ews?
Ill have to loo at the book when I get home

 

My auxilary fan will run anywhere from 5 seconds-1 minute after shut-down...mostly on warmer days after a spirited run. Thought it was normal :dunno:

 

It most certainly could be John...just slight operational differences between cars, may cause some to run a bit hotter or cooler. :dunno:

Hey, I was up at Hardware Sales recently...hadn't been there in over a year...is that not the best place in the world?

 

I guess we need to know what computer type your running... whats the month and year of the car

 

Production date is 10/2000

 

If the car was driven a tad spirited in a hot day, or really spirited in a cooler day, the aux fan might come on. The engine is really hot, and there is no coolant flow. The car still "awake", so it reads the temps. Once the temp of dual temp sensor goes above a certain range (I believe it's 98°C on the i6), it will trigger the aux fan. This can be tested, after turning the engine off, leave the key in posII and unlock OBD - KTMP. You will be surprised.

P.S.: Actually if the temp differential between the dual temp sensor and the radiator outlet temp sensor is smaller than x.xx°C (I am not sure what the value is), then the aux fan is triggered.
If the temp sensor that reads the engine temp is bust (in the dual temp sensor), or if the rad outlet temp sensor is bust, the aux fan will never turn on, and also the electronically controlled t-stat will be never opened more than the max opening in standard mode. The DME thinks the coolant is not hot enough.
Found out about this the hard way.

 

If the car was driven a tad spirited in a hot day, or really spirited in a cooler day, the aux fan might come on. The engine is really hot, and there is no coolant flow. The car still "awake", so it reads the temps. Once the temp of dual temp sensor goes above a certain range (I believe it's 98°C on the i6), it will trigger the aux fan. This can be tested, after turning the engine off, leave the key in posII and unlock OBD - KTMP. You will be surprised.

P.S.: Actually if the temp differential between the dual temp sensor and the radiator outlet temp sensor is smaller than x.xx°C (I am not sure what the value is), then the aux fan is triggered.
If the temp sensor that reads the engine temp is bust (in the dual temp sensor), or if the rad outlet temp sensor is bust, the aux fan will never turn on, and also the electronically controlled t-stat will be never opened more than the max opening in standard mode. The DME thinks the coolant is not hot enough.
Found out about this the hard way.

When I had my cooling system overhaul performed, by a BMW master tech, I provided two boxes of parts..he was impressed with the thoroughness of the parts I supplied (I had every hose, pulley, tensioner, thermostat, water pump, fan clutch, etc, etc)...but he added in the temp sensors, saying it was a good idea to replace them as well.

 

Me7.2

There's your answer... Next time respect people who help this forum out,
If you would have looked thur the stuff blue bee linked you would have found this already..

and get your self a Bentley manual... Next time i have to look in my book for you.. Im going to charge you for it

Customer: Econobox
status :Non waiter
customer stats aux fan runs after shut down
Time :.0025 min diag @ 87.95$/hr

Customers bill .22cents +7%tax= 27 cents

you owe the shop 27 cents..... you can pick your car up monday
next monday....Night

 

Customer: Econobox
status :Non waiter
customer stats aux fan runs after shut down
Time :.0025 min diag @ 87.95$/hr

Customers bill .22cents +7%tax= 27 cents

you owe the shop 27 cents..... you can pick your car up monday
next monday....Night

You forgot the waste disposal fee. $4.

 

I wonder if the OP realizes what BBs response means in terms of future help.

 

I also own a 2007 Honda Odyssey van, the Aux Fan is switched, in other words, when you stop the van and remove the key from the ignition, the Aux Fan turns off, even when the coolant temp is 95-100C. The Honda engineers design the van this way to avoid running down the battery. Plus, once you exit the van, there is really no need to run the Aux Fan. The engine will cool down naturally anyway. This is one aspect of engineering that the Japanese are better than the Germans...

The E39 Aux Fan is wired in such a way that the feed is always hot, i.e., not switched.
So it is normal for the Aux Fan to run a bit after the engine is shut off. Personally, I have never had that experience (never seen my Aux Fan runs after shutdown). I know for fact it works b/c when the AC is on, I see the fan blades rotating.
As mentioned above, the other way for the fan to run non-stop is a bad Coolant Temp Sensor {mounted on the rad for 97-98 models and at the bottom hose for later models).

 

+1..and the point in my previous post...even if the fan runs after shutdown, it is only cooling the radiator, not the engine, since the coolant is not circulating...it is stationary, since the water pump is not running. Typically, even if the fan is allowed to run, the battery will not run down, as the radiator will cool quickly, since there is not that great a volume of coolant in the radiator, and it is not being resupplied with hot coolant from the engine. So really, either way is probably fine...the only time it might be superior to have the radiator fan on a switched leg, is if the battery is marginal, and has little capacity/life left.

 

This thread is closed now lol

 

Burning2nd, thanks for the answer. It looks like running after shutoff is normal, but it's never happened in over 1.5 years to me.

PS: Normally, I search and Google, and have often commended BlueBee's encyclopedic organization on this forum.
However, I am currently having health issues, and for a simple yes/no question (Does the fan stay on, ever?)
I did not want to spend hours researching everything there is to know about the aux fan.
Normally, this is indeed what I do. This time, I just wanted the yes/no answer. Thank you for understanding.

 

Burning2nd, thanks for the answer. It looks like running after shutoff is normal, but it's never happened in over 1.5 years to me.

PS: Normally, I search and Google, and have often commended BlueBee's encyclopedic organization on this forum.
However, I am currently having health issues, and for a simple yes/no question (Does the fan stay on, ever?)
I did not want to spend hours researching everything there is to know about the aux fan.
Normally, this is indeed what I do. This time, I just wanted the yes/no answer. Thank you for understanding.

If the pusher fan stays on after a spirited driving, it's normal. The engine is a tad hotter than when it's driven under "normal" conditions.
If the pusher fan comes on after the car was driven "normal", then chances are the fan clutch is failing.
If the pusher fan never comes on, even if the KTMP shows more than 98°C, but comes on when you turn A/C on, the dual temp sensor is toast, and the car might even overheat (this is if the pusher fan relay checks OK with the GT1).

 

DID anyone read that page?

hes running me 7.2

Its normal..
why is this still going on?
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