2003 BMW 330 Problem starting under 40F

Tiny
LLKING
  • MEMBER
  • 2003 BMW 330
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 71,000 MILES
Hi,

My car seems to have problem start when temp drops below 40F and cold engine. However, I don't have any problems when the engine is warm with either cold/warm air temp.

I've replaced the fuel pump by a certified BMW tech and still having the same problem.

Are fuel pump relay temperature sensitive? Do you recommend replacing it?

thanks
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Friday, April 23rd, 2010 AT 12:33 PM

8 Replies

Tiny
DR. HAGERTY
  • MEMBER
What problem do you have, I'm not clear, is it no start or slow crank or long crank or what exactly? The BMW certified technician has changed the fuel pump, was it bad?
Relays are usually not sensitive to cold.
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Saturday, April 24th, 2010 AT 12:02 PM
Tiny
LLKING
  • MEMBER
The problem is that I can't seem to start my car during cold temp and cold engine even after I've replaced the fuel pump which was recommended by the tech. It cranks but it won't turn over. So, basically, it may not have been the fuel pump having problem.

In the interim, I can start it if I turn off/on a few time before starting the engine. I'm afraid this might cause further damage somewhere down the road.

The tech did a measurement at the fuel pump and saying there's no signal coming from the DME most of the time during that the cold temp. Could it be the fuel pump relay? He recommended to replace the DME. I chose to exclude this info because I think he was just trying to get me to spend more money which may not solve the problem at all.

I'm trying to get second opinion whether to pursue with replacing the DME or try other cheaper alternative first.

Do you believe DME or any of its component can be temperature sensitive?
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Saturday, April 24th, 2010 AT 5:18 PM
Tiny
DR. HAGERTY
  • MEMBER
If the change of the DME does nothing, is he going to cover your costs?
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Sunday, April 25th, 2010 AT 7:43 PM
Tiny
LLKING
  • MEMBER
No, he's not.

For $50, I can send in via express mail to a place where they can run diagnostic on the DME. However, if they do find some defective components or needed to repair it, the maximum cost would be $475.

How do feel about DME remanufacturing?

What other option do you suggest?

I'm thinking of trading it in this summer if there's no fix since the car is paid off.
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Monday, April 26th, 2010 AT 12:01 AM
Tiny
DR. HAGERTY
  • MEMBER
Selling may be your best option, I may be a BMW expert, but I am by no means married to the idea of owning one, especially when my Chevy truck starts and runs just fine thanks.
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Wednesday, April 28th, 2010 AT 11:12 AM
Tiny
LLKING
  • MEMBER
Hi Dr Hagerty,

OK. I found a few other owners having the same problem. Their common solution is the fuel pump relay.

I also verified that the horn relay is exactly the same as the fuel pump relay. I'll attempt to swap them around and try.

I read that the relays are located right behind the fuse panel for the 2003 330xi. The question is do I have to take the glovebox door off to access the relay? Or can I remove the screws holding the fuse panel? Or is there another easier way to access it?

Much appreciate it
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Thursday, April 29th, 2010 AT 1:25 PM
Tiny
LLKING
  • MEMBER
Hi Dr Hagerty,

I did find a website showing how to take the glovebox apart to reach the relay area.

I swapped the horn and the fuel pump relay.

And drum roll please.

The car started this morning on the first start at 42 degrees F.
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Friday, April 30th, 2010 AT 11:14 AM
Tiny
DR. HAGERTY
  • MEMBER
Good on you mate, you could probably knock some of the guys at the dealer out with that one.
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Friday, April 30th, 2010 AT 8:49 PM

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