Originally Posted by trader4 (Post 1042685)

Again, read what I actually wrote. I said that Bentley says the DISA
is there to increase mid-range performance. I said that I don't notice
any difference in performance. The two are not inconsistent. It could
boost performance by a small amount. That is enough to boost
some claimed specs and obviously would impress someone like you,
but it's not noticeable to me in everyday driving. And as I've said,
others here have also said they don't see any difference in performance
either, so why don't you jump on them too? Have you even
tried driving the X5 with the DISA disconnected? What is the
source for your claim that the DISA affects mileage?

Reduced mileage due to an inoperative DISA is what *you*
claimed. First time I've ever heard that and knowing what the
DISA does, it seems unlikely. It seems more likely that a non-working
DISA could actually increase gas mileage. DISA operates by tuning the
intake so you can cram a little more fuel/air mix into the engine.
It decrease the resistance to airflow in the intake.
From what I see, no reason to believe that translates into
increased mileage, just increased performance because you
get more fuel/air in there. More in, you're still having to put extra
gas in to get that performance.

"Your opinion the controller is the same as a fan failure is ludicrous."

You put in a new electric fan system. Whether the fan or the controller
fried in under a year is largely irrelevant. The system still failed.
My stock mechanical fan is still going fine at 160K.


"I'm not going to address your attic fan or a lawn tractor blade bs. If readers know the earth isn't flat they know that means nothing more than you know attic fans and lawn tractors exist."

You just did address it. What you mean is you can't explain how
that small mechanical X5 fan could possibly consume 10hp. That's
why what a real 10hp fan looks like is relevant. It has a fan blade
that is 5 ft in diameter and it moves 66,000 cfm. And again, it's
not an attic fan. For anyone interested, here it is:

DAYTON Med Duty Fan,66,186 cfm,208-230/460V - Belt Drive Exhaust Fans w/Drive Package - 7M872|7M872 - Grainger Industrial Supply

Now *that* is a 10hp fan.

The BMW mechanical fan isn't that. It's not even a home central
air AC condenser fan size. Those are 1/4 to 1/3 hp, drive a
fan blade many 3x the size of the x5 fan and they move
a whole lot of air. So I say physics
says your hp savings are an order of magnitude less than 10hp.
The other thing that makes no sense is that if that fan were
using anywhere near 10hp, then it would be using ~20%
of the hp that the X5 takes cruising down the highway.

Just the facts.

Originally Posted by StephenVA (Post 1042773)

Guys let it go......
If someone approaches a problem with our 10+ year old vehicles with a ROI in mind, the financial return only shows that quick fixes, ignore, band aid repairs, etc. with no thought to longevity would be a rational approach.

I personally like everything to function as designed or to improve it to 2015 technology on my BMWs. Everyone gets to choose as owners. Trust me the coat hanger solutions will be ever more common as these SAVs to onwards to 15 years. The scrap yards will be full of them as repairs will exceed retail value. The Dallas Car Sharks types will be buying X5s for $1500 and butchering them to flip them

Originally Posted by trader4 (Post 1042770)

My driving for a year without an operating DISA with no noticeable
difference in performance, the car running perfectly, is my evidence
that the DISA isn't a critical item. So is Bentley's description of what
it does. That plus my understanding of the principles involved, how
it works, leads me to believe it's non-essential. So, I just stated that
for anyone that's interested. Others have also reported that whether
the DISA was operating or not, they didn't notice any difference.
Have *you* driven you car with it operating, non-operating? IF not
how would you even know?


"The reason why mileage will decrease is that it will take more go pedal to reach and maintain the same speed if the DISA valve is malfunctioning. Less go pedal mean less fuel used"

Again, pulled from thin air without regard to how the DISA operates.
You're making the fundamental mistake that increased performance
means increased performance for free. The DISA tunes the intake
so that you can cram more air and fuel into it. The air is free, the
fuel is not. Just physics.


"should not be used to state replacing the DISA valve is not important. If for no other reason than the pin that goes through the flap can come loose and get into the engine the valve should be replaced as soon as it begins to malfunction. "

Yes, a loose pin is one common malfunction, but there are others.
I assume that people here have some common sense. If you're
DISA is rattling away and has a loose pin it would be pretty dumb
to drive it that way. I never said to do that. I said that with it
not operating I saw no difference in performance. How that gets
translated into driving around with a loose pin, IDK.



"To a significant level the longevity of the fan or the controller is not important to me. "

Your car, your money, your choice. One year after all that work,
doesn't sound so good to me. My stock fan is working fine at 160K miles.

"My guess is you wouldn't know Physics from the back end of a donkey. Accepting you do, I will endorse your claim of what I view as a fantasy even in la la land if you provide the equation proving your claim. That said, your attic fan and lawn tractor comparison is pure nonsense. It doesn't take 10 horsepower to turn an attic fan. The reason they use a that much power is so the motor doesn't have to work hard to turn the blade and so it will last 10+ years."

Now it's very interesting that you claim I don't understand physics
when you just showed everyone here that it's actually *you* who
doesn't understand physics. First, one more time, that fan link I gave
you for a 10hp fan is not an "attic fan". Did you even look at it?
Good grief. A typical attic fan is a small fractional hp motor.
Here is a typical one, it has a 14" fan, moves 1600 cfm and costs $100:

Broan 1600 CFM Power Gable Mount Attic Ventilator-35316 - The Home Depot


That huge *10 hp industrial fan* I showed you is for moving air in a huge
warehouse or similar application. It has a 5 ft fan, moves 66,000 cfm
and costs $4700:

DAYTON Med Duty Fan,66,186 cfm,208-230/460V - Belt Drive Exhaust Fans w/Drive Package - 7M872|7M872 - Grainger Industrial Supply



And now as to the physics, the hp required to move a given amount of air
depends on the volume of air moved, the pressure across the fan, etc.
They size the motor to the fan. No one puts a grossly oversized
10hp fan in an attic fan to make it last longer, that is pure BS that
you just made up. OK, so now let's do some basic physics. The
10hp industrial fan moves 66,000 CFM, the Broan attic fan moves 1,600
That a factor of 41 difference. Take the 10hp and divide it by 41 and
what do you have? 1/4 hp and that's exactly what that attic fan has,
a small fractional hp motor. That's physics for you. The motor power
required is sized to the load. Now answer the simple question,
what size and capacity fan is the X5 closer to? The attic fan or
the 10hp industrial fan?

"It does not take 10 hp to turn a lawn tractor blade."

I never said it did. I only used that as a simple reference to show
what 10hp can really do. Are you going to tell us that X5 stock
fan needs the same amount of power as a lawn tractor mowing
grass?

I won't put you on the list of people to ignore. That's the choice
of the ignorant who are afraid of free speech.

Originally Posted by Takimo (Post 1041372)

another issue again, so i went to my garage to diagnose a/c issue, he told me there no leak, but the main reason why i dont get cold air is because my climate control only send 4volt to the compressor and it doesnt get enought electricity to work... anyone have a DIY solution?? beside replacing this 1000$ shit

+

he also told me, my aux fan is dead, is it a repair ASAP or no ?