Video of N62 Engine suffers from a sudden drop followed by a spike!!!

[Ash977]

2006 BMW X5 4.8is with 37,000 miles... N62 Engine
After the engine has idled and warmed up from a cold start or sitting for several hours, sometimes there is a sudden drop followed by a spike in the engine rpm as captured in this clip. The spike happens when rpm is being lowered by the computer. No yellow or red lights go off.
http://www.youtube.com/watch?v=lCyXANcj9xQ
The dealer tells me since they can’t duplicate this there is nothing they can do about it. Anyone has experienced this issue??? Any idea what the culprit is?
Thanks a lot,

[Ash977]

One more video from 3,000 miles ago...

Its happens 30 second into the clip:
YouTube - 2006 BMW X5 4.8is - Sudden Drop/Spike in the Engine rpm 2

[m5james]

Does it rain heavily where the X is kept? The only thing I can relate to is that when I've driven through heavy rain areas and I get Trans Failsafe codes from the trans computer getting wet, so the truck would act oddly and sometimes do the exact same thing until everything dried out. It happened recently actually when I was driving from Boise to Reno through the rain, came to an abrupt stop off the Reno exit and BAM...TFS code. The next day I had issues even starting the X, but once it finally did, it would do the same thing. I've yet to take apart the ECU box and see how to remedy my problem.

I don't know if you have an Android or iPhone, but I have an Android and use an app called Torque (iPhone has similar apps) then a simple $20 bluetooth OBDII device that I can use to monitor 02 sensors, fuel injector pulsing, ambient air temps, etc...all from my phone.

[UCrewX5]

Can you duplicate it? I assume so since you have been able to capture it twice on video.

[Ash977]

m5james – thank you for your response. No, it doesn’t rain in Los Angels that often. This can happen in a sunny day or a hot summer afternoon… but cold weather makes it happen more often… I have the HTC Evo, an android phone. I will look into that application. Thanks a lot for the tip…

UCrewX5 – thank you for your response. I am getting closer to become a master in duplicating this problem, hehe. I pretty much video every time I start the engine when I believe there is a chance of this happening. I got lucky several times so far.

[m5james]

Originally Posted by Ash977

m5james – thank you for your response. No, it doesn’t rain in Los Angels that often. This can happen in a sunny day or a hot summer afternoon… but cold weather makes it happen more often… I have the HTC Evo, an android phone. I will look into that application. Thanks a lot for the tip

I wasn't sure since I saw LA in your location, so I was thinking Louisiana. Anyways, here is the OBDII device ELM327 OBDII OBD-2 V1.4 Bluetooth Scan Tool Interface | eBay and then you can download a free version of Torque from the Market or PM me and I'll guide you to a place where you can get hundreds of paid apps for free.

Quick video I found - YouTube - Torque on Evo 4G (In Depth View)

[Naz24]

I've seen that happen before. check intermediate levers? maybe..

have you gotten any Service engine soon lights to read codes from?

[Ash977]

Hey Naz - Thank you for your reply. No engine light what so ever...

[Naz24]

Originally Posted by Ash977

Hey Naz - Thank you for your reply. No engine light what so ever...

funny thing is that this happened to my moms 4.6is, it kept doing this, until finally the thing shut off once and displayed engine failsafe mode. The problem? Dislodged intake.. check the simple things first!

[Pisendar]

I was told long time ago it could be due to idling system failing an only who can fix it is Dealer because they supposedly have right equipment.

What exactly dealer told about that?!