Starting from cold, rough running
11-15-2012, 08:07 AM
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Starting from cold, rough running
Hello all, I am new here and hoping you guys can get a newbie out of trouble
The car is a 2007 E61 530i with the N53B30A Engine.
When starting on a cold morning for the first few minutes the engine run rough, slow to pick up, hunts at idle and seems to misfire.
Once I have the throttle down it is much better, still notice the misfire though
After a few mins driving the fault disappears and the car runs great. It feels like the problem improves rather than just instantly disappears but this could be just my feeling.
At the time when it goes away I am always driving up a very long hill so throttle down and the engine is really working.
When I leave work later in the day the “misfire” is there but nowhere near as bad, its warmer at that time of course.
I was told MAF, so I got a nice shiny new one, genuine BMW part not a copy, the old one did look dodgy, should the white plastic part be floating loose just held by the 2 wires??
New MAF fitted, identical fault, no change at all.
I scanned for fault codes ODBii things, not one, nothing. No warning lights or service indicators either. I had it scanned with engine off, engine running and misfiring and engine running nice and warm and perfect. Nothing.
My next guess is an O2 sensor however I’m told these don’t come into play until the motor is warmed up, is that correct. Open loop/closed loop ?
If not then what tells the engine that it is not cold anymore? How is mixture metered when its cold?
Car is out of warranty and the local stealers apart from being very unfriendly and unhelpful charge a total fortune just to say good morning.
Sorry the request is so long, I tried to give as much info as I could.
The car is a 2007 E61 530i with the N53B30A Engine.
When starting on a cold morning for the first few minutes the engine run rough, slow to pick up, hunts at idle and seems to misfire.
Once I have the throttle down it is much better, still notice the misfire though
After a few mins driving the fault disappears and the car runs great. It feels like the problem improves rather than just instantly disappears but this could be just my feeling.
At the time when it goes away I am always driving up a very long hill so throttle down and the engine is really working.
When I leave work later in the day the “misfire” is there but nowhere near as bad, its warmer at that time of course.
I was told MAF, so I got a nice shiny new one, genuine BMW part not a copy, the old one did look dodgy, should the white plastic part be floating loose just held by the 2 wires??
New MAF fitted, identical fault, no change at all.
I scanned for fault codes ODBii things, not one, nothing. No warning lights or service indicators either. I had it scanned with engine off, engine running and misfiring and engine running nice and warm and perfect. Nothing.
My next guess is an O2 sensor however I’m told these don’t come into play until the motor is warmed up, is that correct. Open loop/closed loop ?
If not then what tells the engine that it is not cold anymore? How is mixture metered when its cold?
Car is out of warranty and the local stealers apart from being very unfriendly and unhelpful charge a total fortune just to say good morning.
Sorry the request is so long, I tried to give as much info as I could.
02-26-2013, 06:15 AM
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My Ride: 2005 545i Sport
Sounds like an injector issue. Fuel saturates the combustion chamber and spark plug when the injector is leaking.
I'd bring it to the dealer or trusted indy shop and leave it over night for an early AM test.
I'd bring it to the dealer or trusted indy shop and leave it over night for an early AM test.
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