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Discussion Starter #1
Hi,

I have a 2005 325i with about 100,000 km on it. The car starts quickly all summer, fall and spring but as soon as the temperature dips below -2 Celsius, it requires multiple and lengthy cranks to start in the morning. Once it does start, it starts well for the rest of the day. However, the next morning, same observation (ie., difficult to start) if the temperature is below -2C.

The very same thing happened last winter so I would like to fix it now. I changed the battery and it did not help.

Any ideas are appreciated??

Thanks!
 

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well...

as long as everyone is saying, maybe...

maybe the coolant temp. sensor. Mixture not enriched enough in cold weather?
 

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Discussion Starter #5
Thanks for the info

I'll have these thinks checked out. Thanks.

One question, what is the best way to determine whether the fuel pump is being primed? Where and when (presumably when I am cranking the engine?) is the best place to hear it?
 

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When you turn the key from Position1 (Accessory) to Position2 (Engine on) so that when you engage the starter at Position 3, the fuel rail will be pressurized. Should hear the pump hum merrily if you put the ear to the rear seat bench, driver's side.

Note that the pump starts, runs for a few seconds pressurizing the rail, then shuts off. It will start up again until the engine is running to avoid flooding it or becoming a fire hazard. I believe the DME uses the camshaft sensors to detect whether the engine has started, so if they're bad you will get a no-start condition, but that should also throw a bunch of codes to fetch with the scanner.

Funny, with all the sensors and sh!t these cars carry, nothing monitors fuel line pressure. So if the pump, the pump relay or the pump fuse are dead, you will also get a no-start condition but no codes will appear! (Don't ask me how I know.... :mad:)
 

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Discussion Starter #7
Interesting...

Thanks, I never would have guessed to listen there. Next time I start it, I'll listen to my back seat drivers side. (Another wild and exciting Friday night) :)
 

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make sure you coolant is BMW original coolant and is mixed with water with the right amount. and also check your vaccume hose for any air leaks. if the car does not turn off after u turn it on, (even though you say it turns on wierd when its cold), i hardly doubt its the fuel pump. you will feel the rpm drop and rise while you have your foot on the gas pedal steady. ie, if your goin 60, and your rpm drops and rises, you should feel it under your foot as well, then it should be your fuel pump.
 
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