E89 Idle Engine Issue (Shutdown or Drops Hard)

JockinJD · Post by **JockinJD** » Sun Sep 27, 2020 2:14 pm

Having an issue that's existed for a while but seems too potentially more of a problem lately.

It's been at the mechanics to do testing such as air flow tests to see if any pipes are split or sensors and these haven't shown problems.

I'm reading a lot about the IAC Valve (Idle Air Control Valve) needing cleaning due to carbon build ups but online seems to show two completely different models perhaps due to the E85 and E89 using two different ones.

Does anyone know firstly what he IAC Valve looks like on an E89 and where it's positioned?

Attached are two youtube links that give both scenarios where I could drive for 20 minutes pull over and within 15 seconds the idle starts to misbehave or engine stall. Could in a different scenario take 5 minutes before anything starts to happen, but when it does start to go south the car shakes when the rough idling happens.

2009 BMW e89 Sdrive 23i

Uploaded some videos to show behaviour

idling shut down scenario
[youtube] https://youtu.be/Oi1GoA4sY_g [/youtube]

idling rpm dropping scenario
[youtube] https://youtu.be/5M3uQpa33_0 [/youtube]

What i'm asking for in a way is to know if anyone has had this issue on their E89 and what steps they took to resolve? I'm keen to stat with checking the IAC Valve, but really want any insight/assistance from you guys who know more about this great car!

No issues when applying revs ever.

Josh

tintoverano · Post by **tintoverano** » Sun Sep 27, 2020 2:17 pm

hi, what engine?

JockinJD · Post by **JockinJD** » Sun Sep 27, 2020 2:19 pm

Oh whoops good point, updated original post regarding.

Its the 2009 BMW e89 Sdrive 23i

tintoverano · Post by **tintoverano** » Sun Sep 27, 2020 2:21 pm

any fault codes perhaps?

JockinJD · Post by **JockinJD** » Sun Sep 27, 2020 2:25 pm

A fault code does appear when the issue is happening but the mechanic has stated it's not related to it at all, i'll actually get the error it states tomorrow to give that extra detail probably should of waited to have the list of any bits of work done over the last week.

tintoverano · Post by **tintoverano** » Sun Sep 27, 2020 2:31 pm

yeah, try to get all the codes

reason can be a couple of things, depending on what was serviced and when: spark plugs, injectors, ...

tintoverano · Post by **tintoverano** » Sun Sep 27, 2020 2:33 pm

it is also possible to record live engine data

need a laptop, cable and software

see the video I made for such a SW in my signature

Phil40 · Post by **Phil40** » Sun Sep 27, 2020 2:59 pm

Hi JockinJD Hi tintoverano

Quick question : is it possible to increase "default" idle engine ?
Mine (engine T° normal) is around 600rpm. It will be better about 800rpm (better noise engine)....

tintoverano · Post by **tintoverano** » Sun Sep 27, 2020 3:11 pm

never tried on a z4, but it is possible using ISTA+

let me know if you want to give it a try

Phil40 · Post by **Phil40** » Sun Sep 27, 2020 3:16 pm

You mean ISTA-D (not ISTA-P) ? It can be great if value (new idle rpm) is saved after engine off...

tintoverano · Post by **tintoverano** » Sun Sep 27, 2020 3:18 pm

yeah, D and it gets saved

JockinJD · Post by **JockinJD** » Sun Oct 04, 2020 4:26 pm

Lets put my post back on track hey

So I spent time with my Mechanic and carried out some more tests for this issue after a 15 minute drive. Please read all including the ending.

So putting it through a scanner and running checks whilst idling shows an error 2D06 - Air Mass System error. (See attached) and also included is the graph results of a test. After doing the 15 minute drive, within a minute of the engine running on idle the engine went from 600 rpm to 250 up to 800 (car shaking) then 45 seconds later did the same again then a minute later it went down rpm and then engine shut off.

Work mechanic has done and tested.
- Fuel Pressure Test
- 5-bar running pressure
- 4.5 bar engine pressure
- MAF Replaced (Continental Part (should be oem))
- All connectors cleaned
- Air leaks checked

Now here's the interesting thing, so obviously had the engine immediately running idle after the 15 minute drive, the rpm went crazy twice within 3 minutes with it at the end, the engine dieing.
I then immediately cut the engine and unplug this new MAF sensor, switch back on with the sensor and the engine ran flawless for 12 minutes no issue, no blips nothing...
Then plug the sensor back in, bear in mind this is a new MAF sensor and the engine acted the same before this new part, within 90 seconds the engine had switched off.

Currently looking to find someone with the same model or engine that uses the same Sensor, to test a confirmed working one. Hopefully will get to do this Wednesday evening, praying to god it proves the continental/bmw sensor I have is the problem.

Does anyone know if it must be an exact BMW MAF sensor needed for the car? Had problems using a Continental version? Cost around £250 from BMW, but hopeful this test proves it and i'll pay the cost.

Thanks chaps.

tintoverano · Post by **tintoverano** » Sun Oct 04, 2020 6:59 pm

isn't it something with wrong adaptations?

what does INPA show?

JockinJD · Post by **JockinJD** » Sun Oct 04, 2020 9:33 pm

Can you elaborate?

tintoverano · Post by **tintoverano** » Mon Oct 05, 2020 8:51 am

I'd check what INPA shows under live analog data, if there's anything

if all seems normal, try cleaning vanos solenoids and/or try using some oil/fuel additives to clean stuff

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