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post #1 of 6 Old 26th June 2019, 03:27 AM Thread Starter
roarf
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Vanos test results inconsistent

How accurate is the DIS Vanos test really? I ran these tests one week apart and am getting wildly different results. Car was fully warmed up prior to running the tests.

(Week 1 result --> Week 2 result)
Bank 1 Intake = 2.8 --> 9.3
Bank 1 Exhaust = 20.9 --> 3.5
Bank 2 Intake = 1.9 --> 12.8
Bank 2 Exhaust = 13.2 --> 18.1

The last time I ran it was after cleaning out the solenoids about a year ago. The results I got then were:

Bank 1 Intake = 4.6
Bank 1 Exhaust = 3.8
Bank 2 Intake = 0.2
Bank 2 Exhaust = 11.9

'14 Evora S - Chrome Orange/Ebony
'02 M5 - Carbon Black/Silverstone
'01 M3 - Imola Red/Black (gone but not forgotten)
'08 RS4 - Imola Yellow/Black (gone but not forgotten)
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post #2 of 6 Old 26th June 2019, 05:08 PM
Sailor24
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It is not a test of numbers more like ranges. You can cheat it too, or it might allow for your cheat but put your car in better running environment. My bet is it is only as accurate as it needs to be. Likely all that really matters is the pass/fail concept. For all the time I have looked at the reports, only a few relationships form and those numbers can be easily changed by manually changing the rpm of the car.

I would say don't worry about the report as long as you pass. If you fail then I would look at the numbers to see why then visually inspect that part of the vanos that apply to those numbers.

Last edited by Sailor24; 26th June 2019 at 05:18 PM.
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post #3 of 6 Old 27th June 2019, 12:01 AM Thread Starter
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What kind of an effect does raising the rpm have? It makes sense to look at it as strictly pass/fail, but when it fails one time then passes the next time it's hard to know if there's actually a problem or not.

At any rate, based on the 2 tests I ran recently and the 1 from a year ago, the only thing that's consistent is Bank 2 Exhaust being above 5 deg. So is it safe to say that one needs additional cleaning or replacement?

'14 Evora S - Chrome Orange/Ebony
'02 M5 - Carbon Black/Silverstone
'01 M3 - Imola Red/Black (gone but not forgotten)
'08 RS4 - Imola Yellow/Black (gone but not forgotten)
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post #4 of 6 Old 27th June 2019, 06:11 PM
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Raising the RPM will pass a car with loose chains, one that has a worn vanos hydraulic pump, and some others sorry don't remember. Those are the important ones, loose chains is common, but the second shows why you may not want to raise that rpm.
Vanos diagnosis most often comes down to inspection. I have run that test, but I really don't like the BMW programs, they are not intuitive and I never feel confident using them. As a result I don't run that test much, only when I absolutely need extra info.

If you don't have any codes or symptoms, stop running the test! If you have a reason to run the test the simple thing to do is test switch boards side for side and test again. A lot of lodgic can be applied to that simple step of switching boards.
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post #5 of 6 Old 27th June 2019, 11:33 PM Thread Starter
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Quote:
Originally Posted by Sailor24 View Post
Raising the RPM will pass a car with loose chains, one that has a worn vanos hydraulic pump, and some others sorry don't remember. Those are the important ones, loose chains is common, but the second shows why you may not want to raise that rpm.
Vanos diagnosis most often comes down to inspection. I have run that test, but I really don't like the BMW programs, they are not intuitive and I never feel confident using them. As a result I don't run that test much, only when I absolutely need extra info.

If you don't have any codes or symptoms, stop running the test! If you have a reason to run the test the simple thing to do is test switch boards side for side and test again. A lot of lodgic can be applied to that simple step of switching boards.
Fair enough, thanks for the insight. Switching boards side to side makes sense. I don't particularly like DIS either.

Is the way the test runs hard on the engine or something? Just curious why you say not to run it if you don't have any codes.

'14 Evora S - Chrome Orange/Ebony
'02 M5 - Carbon Black/Silverstone
'01 M3 - Imola Red/Black (gone but not forgotten)
'08 RS4 - Imola Yellow/Black (gone but not forgotten)

Last edited by roarf; 27th June 2019 at 11:33 PM.
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post #6 of 6 Old 28th June 2019, 01:21 AM
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Only because I don't like running it. For that I have to find my laptop and cord that is to short and then the adapter for under the hood. Next I am bent over because my cord is to short. If I use my pro OBDII scanner I can sit in the car run some tests it has, similar to the vanos test but not as in depth. I get a feel for things. I can open any of the 8 noids in pairs and see where the cams go then watch how they recover. This gives me something to inspect. I have a ton of tricks to get closer, I might choose to switch two noids for each other and test again. Generally I have rebuilt enough boards I just do that and things work out.
I am big on the least hassle is the best way. Playing with the boards is the least hassle for me always. That DIS thing and my laptop are a huge hassle. Strangely I do everything on my RS4 with the laptop first but the program I use for it is very intuitive and its cord is 12' long.
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