Idle frequently dropping below 500rpm
02-03-2015, 08:51 AM
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My Ride: 2006 550i Sport, Titanium Silver Metallic on Black, HUD, NAV, BMW Assist, Active Steering
Idle frequently dropping below 500rpm
Hi, I have an annoying issue with my 06 550i with 91K. When engine is fully warmed up, the idle drops down to around 475 and periodically fluctuates a bit. Also occasionally, when I am coming to a stop and transmission does something the engine speed drops down to 450. No CEL or codes.
Anyone experience this issue?
Could it be DISA valve going bad? Leaking fuel injector or vacuum leak?
I am hopping its from carbon deposits and will try cleaning those up.
Anyone experience this issue?
Could it be DISA valve going bad? Leaking fuel injector or vacuum leak?
I am hopping its from carbon deposits and will try cleaning those up.
02-03-2015, 03:52 PM
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My Ride: 550i
Model Year: 2010
What is the idle speed according to the hidden dash menu?
I ask because according to the tach, my 550i idles at just under 500 rpm with the A/C off, but according to the hidden menu, it's really 550 rpm.
Do you still have the original spark plugs?
I'd throw in a bottle of techron at the next fill-up and see if that smooths it out.
I ask because according to the tach, my 550i idles at just under 500 rpm with the A/C off, but according to the hidden menu, it's really 550 rpm.
Do you still have the original spark plugs?
I'd throw in a bottle of techron at the next fill-up and see if that smooths it out.
02-04-2015, 10:29 AM
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My Ride: 2006 550i Sport, Titanium Silver Metallic on Black, HUD, NAV, BMW Assist, Active Steering
Thanks. I will check on the idle speed under hidden menu and report back. I just received Liqui-Moly 6 month maintenance kit from Bavarian Autosport, so I will go through that protocol and see what happens. It includes moly's "Valve Clean" which they claim deals with idle instability.
02-06-2015, 03:24 PM
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A couple of thoughts; Clean the Air Mass sensor and check for vacuum leaks (hoses etc.)
02-07-2015, 02:20 PM
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My Ride: 05 530i M54
Model Year: 05 530i
Engine: 3.0 M54
Its rare that the MAF would be bad @ 91k but who knows with these cars. I would check for vacuum leaks for sure and through in some seafoam to clean out the system and go from there.
02-09-2015, 06:42 PM
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My Ride: 2006 550i Sport, Titanium Silver Metallic on Black, HUD, NAV, BMW Assist, Active Steering
Thanks for your responses. I had my indy clean the MAF a couple of months ago and that didn't help. I am not a big fan of seafoam. I am waiting for my next fillup to put in liqui-moly valve clean. I used their jectron fuel system cleaner in the last tank of gas and got 2 more mpg.
Few months after I bought my car the CCV went bad and I didn't know until I took it in for an oil change a few months later. I am sure that caused allot of deposits to build up on the valves. If cleaning them doesn't help, I will have my indy check for vac leaks again.
BTW, I have not been able to get to the hidden menu to see the idle setting but I will try again this weekend.
Few months after I bought my car the CCV went bad and I didn't know until I took it in for an oil change a few months later. I am sure that caused allot of deposits to build up on the valves. If cleaning them doesn't help, I will have my indy check for vac leaks again.
BTW, I have not been able to get to the hidden menu to see the idle setting but I will try again this weekend.
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