BMW M5 Forum and M6 Forums banner

1 - 12 of 12 Posts

·
Registered
Joined
·
166 Posts
Discussion Starter #1 (Edited)
I got my car with around 70k miles on it
when i first got it i noticed how the idle fluctuates at warm starts.
i never took it into account until one day it entered limp mode on the highway i parked aside and it gave an error
Idle actuator malfunction Bank 2

got a new actuator from ecs placed it with two new actuator hoses
and the error went everything went back to normal however the idle fluctation remained

at cold start it fluctuated for around 30sec then just remains steady
at warm starts and after fueling up it does it for around 1 min then returns back to normal , whether at a stop light or at idle its steady

This is only happening when i start the car at warm start and im pretty sure a car of this value and status must not be doing it,

Has anyone had this happen to them? if so please help since no codes are being thrown and its just annoying to be honest
 

·
Registered
Joined
·
272 Posts
I got my car with around 70k miles on it
when i first got it i noticed how the idle fluctuates at warm starts.
i never took it into account until one day it entered limp mode on the highway i parked aside and it gave an error
Idle actuator malfunction Bank 2

got a new actuator from ecs placed it with two new actuator hoses
and the error went everything went back to normal however the idle fluctation remained

at cold start it fluctuated for around 30sec then just remains steady
at warm starts and after fueling up it does it for around 1 min then returns back to normal , whether at a stop light or at idle its steady

This is only happening when i start the car at warm start and im pretty sure a car of this value and status must not be doing it,

Has anyone had this happen to them? if so please help since no codes are being thrown and its just annoying to be honest
Check out this thread:

http://www.m5board.com/vbulletin/e60-m5-e61-m5-touring-discussion/519625-vanos-solenoids-3-way-cure-warm-idle-highway-cruise-low-end-response-tq.html
 

·
Registered
Joined
·
1,432 Posts
1. If it's due to the VANOS solenoids, then it could be small metal particles jamming them. This suggests recent excessive bearing wear. There are individuals with almost new solenoids that fail the DIS / ISTA tests. Who knows why? Take the results with a grain of salt, but check your oil and filter.
2. You replaced the Idle actuator. What about the throttle actuators? Do they have any codes?
3. Vapour charcoal cannister. Seems like a low risk / low cost fix to try.
 

·
Registered
Joined
·
166 Posts
Discussion Starter #6
1. If it's due to the VANOS solenoids, then it could be small metal particles jamming them. This suggests recent excessive bearing wear. There are individuals with almost new solenoids that fail the DIS / ISTA tests. Who knows why? Take the results with a grain of salt, but check your oil and filter.
2. You replaced the Idle actuator. What about the throttle actuators? Do they have any codes?
3. Vapour charcoal cannister. Seems like a low risk / low cost fix to try.
1-bearings changed at 75k miles
2-no throttle actuator faults
3-didnt try that yet but i will start from there
 

·
Registered
Joined
·
166 Posts
Discussion Starter #7 (Edited)
I would recommend you to take a look at your Vapor Charcoil Canister and change it. It's a quick change and is often the culprit for fluctuation in idle.
See also the link below

http://www.m5board.com/vbulletin/e60-m5-e61-m5-touring-discussion/318905-activated-charcoal-filter-aka-vapor-canister-gas-tank.html


Terry
i will and thanks for the link i will start with this since its at around 75k miles ill do it anyways

Get your vanos solenoids tested via DIS, INPA, etc
if the above does not work then i will test the solenoids and check and get back to u with the results
 

·
Registered
Joined
·
166 Posts
Discussion Starter #8

·
Registered
Joined
·
1,432 Posts
but one question why would it cause idle fluctuation?
The last post in the link say that "...it's a well known fact..." or some such thing. But, I've seen no support for this. In fact,I'm not sure that I believe it. In threads I've read, someone always suggests it but I have yet to see a post "....Changed my charcoal cannister in the passenger wheel well and the hunting / surging idle went away... ". I'm beginning to think that there are different causes depending on a cold start or a warm start.

idle surge on warm start
This thread here has two solutions. One surging idle was solved by replacing the solenoids. The other by replacing the spark plugs.

idle surge on cold start

One user here says that its the charcoal cannister - but the OP never comes back to say what the resolution was - and it's a very recent thread.

This thread went on for 9 pages about the problem - from a warm start (after filling up with gas etc). You see a lot of "The charcoal canister.... it's the charcoal canister... " but no one ever replaces theirs except one person.

Even our own Jcolley had the problem here after filling up a gas tank - he talks about charcoal cannister. But there is no resolution.

This post in that same thread shows that in at least one case, changing the charcoal cannister made no difference. It's funny that with so many people pushing that (we'll call it a) myth, that I can only find one case of someone trying it as a solution. p.s. It didn't work.

There is also a lot of carrying on about the Euro DME tune versus the USA and how one poster had the problem disappear when they go Euro. (once you go Euro, you never fear-o???)


Starting at this post, there is discussion about it being a coil and a failing thermostat (increased emissions).

This guy (he of the infamous el Guapo I've seen talked about by some indy or another on the web) says that it was related to two fuel tank vent valves and a small vacuum leak. But, I think that he is talking about the "increased emissions" code and not the idle surge on warm start.

Someone else updated to the latest software and it cured the idle surge. Someone else replaced their throttle actuators and it cured the idle surge.


You get the picture. It's going to be different everytime. The idle surge is a symptom of diverse problems.
 

·
Registered
Joined
·
158 Posts
This seams to be a common symptom with these cars...Not sure if anyone really knows why. I don't believe its a big problem, but sounds like its a result of low Vanos solenoids values.

I have a feeling a bad Charcoal Canister Filter would yield a different idle fluctuation symptom...

Can you hear the exhaust tone change at constant highway speeds without a fluctuation in RPM?
 

·
Registered
Joined
·
1,432 Posts
You can use ISTA. Click on the DME on the chart of all the modules. Then one of the buttons below will give you the component tests. There should be a VANOS one. The Solenoids can be tested there.

Personally, I don't believe in that test given what people have reported for new solenoids and how the test results fall rapidly to fail. Either replace them or don't.
 
1 - 12 of 12 Posts
About this Discussion
11 Replies
7 Participants
gmak
BMW M5 Forum and M6 Forums
M5Board is the best forum community for information on the BMW M5 E60 (V-10), E39 (V-8), E34 (straight 6), E28, F90 and F10. Discuss performance, specs, reviews and more!
Full Forum Listing
Top