2004 BMW 545i N62 E60 Warm up problem. Tech needed.
The oil is getting into your intake through the ccv off the valve covers. Usually a leak causes this. Valve cover gaskets, a crack in you ccv hoses, etc. Pull one of the ccv hoses off your intake manifold. You'll see oil around the fitting and in the hose.
i'd maybe lean towards o2 sensors. a cold engine starts in open loop, then when the o2 sensors warm up, the engine goes into closed loop. a o2 sensor giving the wrong reading can be telling ecm to add more or less fuel than needed.
here is something that kinda explains it better. not specific to bmw.
here is something that kinda explains it better. not specific to bmw.
Difference Between Open and Closed Loop
dave8412 Jun 16 2006 - 11:34am
Q: What is the difference between 'Open Loop' and 'Closed Loop'?
A: When the engine is first started, and rpm is above 400 rpm, the system goes into 'Open Loop' operation. In 'Open Loop', the ECM will ignore the signal from the Oxygen (O2) sensor and calculate the air/fuel ratio based on inputs from the coolant and MAF sensors, but mostly from a pre-programmed table in the memcal.
The system will stay in 'Open Loop' until the following conditions are met:
1. The O2 sensor has varying voltage output, showing that it is hot enough to operate properly. (This depends on temperature)
2. The coolant sensor is above a specified temperature about 40oC/104oF.
3. A specific amount of time has elapsed after starting the engine.
The specific values for the above conditions vary with different engines and are stored in the mem-cal. When these conditions are met, the system goes into 'Closed Loop' operation. In 'Closed Loop', the ECM will calculate the air/fuel ratio (injector on-time) based on the various sensors but mainly the O2 sensor. This allows the air/fuel ratio to stay very close to 14.7:1.
dave8412 Jun 16 2006 - 11:34am
Q: What is the difference between 'Open Loop' and 'Closed Loop'?
A: When the engine is first started, and rpm is above 400 rpm, the system goes into 'Open Loop' operation. In 'Open Loop', the ECM will ignore the signal from the Oxygen (O2) sensor and calculate the air/fuel ratio based on inputs from the coolant and MAF sensors, but mostly from a pre-programmed table in the memcal.
The system will stay in 'Open Loop' until the following conditions are met:
1. The O2 sensor has varying voltage output, showing that it is hot enough to operate properly. (This depends on temperature)
2. The coolant sensor is above a specified temperature about 40oC/104oF.
3. A specific amount of time has elapsed after starting the engine.
The specific values for the above conditions vary with different engines and are stored in the mem-cal. When these conditions are met, the system goes into 'Closed Loop' operation. In 'Closed Loop', the ECM will calculate the air/fuel ratio (injector on-time) based on the various sensors but mainly the O2 sensor. This allows the air/fuel ratio to stay very close to 14.7:1.
Thread Starter
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Joined: Jul 2013
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From: Huntington Beach
My Ride: 04 545i 6spd Navi Cold Weather
Ok thank you for that suggestion and yeah that sounds like my next step. Second person to bring that up. Now what do you think, should I replace all of them or one by one starting with post cat? Might be cheaper if mechanic does all of them at once?
o2 sensors are not cheap, and i think the v8 has 4 of them. does your car burn any oil? bad valve stem seals? burning oil can possibly be messing with the o2 sensors.
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Joined: Jul 2013
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From: Huntington Beach
My Ride: 04 545i 6spd Navi Cold Weather
You know.. now that you say that. It did need some oil when I took it on a long trip. It has a very minor oil leak though. I know see oil drip when the car has been on for longer than 1 hour.
However I dont have white smoke coming from the car. Maybe rarely when I have a bad start. Do you think I could have a minor leak in my valve stem seals?
However I dont have white smoke coming from the car. Maybe rarely when I have a bad start. Do you think I could have a minor leak in my valve stem seals?
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My Ride: 04 545i6 Mystic Metallic Blue
FYI when changing O2 sensors just change the pre-cat ones 2x, the post cat O2 sensors just measure for catalyst efficiency. So buy front 2 not back 2. And cleaning the maf sensor doesnt mean its not already gone bad, so you may bite the bullet and get a new one as well.
go with a thermostat first. i had the increased emissions message and a dealer told me to look at the thermostat. i ordered one it will be in today . if you do a search for thermostat the increased emission message follows. i think the ECM tries to keep adding fuel to warm the engine up and throws off the emissions , or it would pull timing and fuel if it was running hot.
well good luck
well good luck
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New Members
Joined: Jul 2013
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From: Huntington Beach
My Ride: 04 545i 6spd Navi Cold Weather
Ok sounds good. So I guess start with the least expansive probable cause..
1) MAF - easy install
2) Thermostat - not terrible and doable..
Pelican Technical Article - BMW E60 - N62 8-Cylinder Thermostat Replacement
3) Oxygen sensors(front 2) - most expansive.. (need mechanic)
So I will save up and start knocking these out.
Thanks for your help guys!
1) MAF - easy install
2) Thermostat - not terrible and doable..
Pelican Technical Article - BMW E60 - N62 8-Cylinder Thermostat Replacement
3) Oxygen sensors(front 2) - most expansive.. (need mechanic)
So I will save up and start knocking these out.
Thanks for your help guys!


