Question about 2003 BMW 325

2 Answers

My 2002 BMW 325I will not start in cold weather. I took it to the BMW dealer and they've replaced the fuel pump....still has not fixed the problem and I'm returning it to them tomorrow. I read that it could be the Coolant temperature sensor....sending the wrong signal to the computer's fuel metering. could this be it. It's not the starter and not the battery..the engine starts fine at any other time or after its been warmed up. I have kept the car in the garage to avoid getting the engine block too cold.

Posted by on

  • 2 more comments 
  • fredmjr Feb 24, 2009

    the car's engine cranks but does not fire up...there are no indications on the dash. My biggest problem is when I'm traveling and have to leave the car outside absolutely will not crank up the next morning if the Outside Temperature is below 45degreesF. I let the car sit and when it gets warmer outside...I'm able to get the car to fire up. Then once the car has warmed can be shut down and will crank right back long as the coolant temp is warm. It will not fire up if the car has been left outside and the temp coolant is cold. BMW Service center has replaced the fuel pump (twice now) and I've returned the car to them this morning to try to figure this out.....they assure me that they will leave the car outside over night to duplicate the problem. I've read on internet postings that this could be a faulty coolant temp sensor....any ideas?

  • kimmiekim Apr 23, 2009

    2002 BMW 325ci will not start in cold weather. Works great when the weather warms with no problems at all. When trying to start in the cold it turns over but will not start. I have had this checked out several times with nothing working. This is very frustrating because this car is great... for a summer car.

  • kimmiekim Apr 23, 2009

    2002 BMW 325ci will NOT start in cold weather. It will turn over but will not start. No lights come on the dash - not even the check engine light. I have had this checked out with no solutions. This is very frustrating because this is a really nice car (for a summer car).

  • joe May 11, 2010

    when you say not started in cold weather, does the engine crank, but doesn't fire or doesn't even crank? if the latter, do you get any lights on the dash or is it completely dead?



2 Answers

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • BMW Expert
  • 223 Answers

Hi Fred, kind of sounds like you have a sticking, or contaminted idle valve. when it is 40-45F outside, a sticking or contaminated valve will cause the fuel mixture to be to rich. as the temp warms, the mixture requirement is not as rich. a quick check is to hold the gas pedal to the floor for 5-10 seconds when cranking cold and then let up. if it seems like it wants to start, the valve is faulty.

Posted on Mar 23, 2009

  • BIMMERX325I Mar 10, 2011

    I finally figured it out. The engine was not receiving fuel from the fuel pump during ignition start (when i turned the key). The started would spin and the motor cycled but did not start. As you start the vehicle, you should hear a slight sound from under the rear seats (the fuel pump). If you do not hear the fuel may have the same problem. What I discovered is, that I had a faulty fuel pump relay switch. The fuel pump relay also is very temperamental in cold weather (below 40F) it doesn't send the signal to the fuel pump. The fuel pump relay is a $15 part and is easy to replace. To do so, remove the glove box and the relay switch box is located behind the glove box location. The part is available at the dealership.


  • Level 1:

    An expert who has achieved level 1.

  • Contributor
  • 1 Answer


BOOM! Identified!

Posted on Apr 08, 2009


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya Mechanic can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repair professionals here in the US.
click here to Talk to a Mechanic (only for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Bypass fuel pump relay on 2002 bmw 325i

change the fuel pump relay it could be any one of the pins

Jul 18, 2014 | 2003 BMW 325i

1 Answer

I replaced the fuel still wont you think it is the relay switch 2006 325i

The relay should have been trouble shot BEFORE changing out the pump. If you've got 12v at the pump it is not the pump. Unless you installed a bad pump. But, no 12v at the pump= bad relay. But ten you've got to see what activates the fuel pump relay.

Jun 21, 2011 | 2006 BMW 3 Series

1 Answer

The windshield washer quit working on my 2003 325i BMW and the fluid id full. what are the possible problems and fixes?

If you don't hear the pump spinning or pumping then it's a possible bad electrical pump, or it's the wiring to it, a fuse, or the fluid is frozen in the pump if the weather is too cold (below 32 deg. F with 32 deg. F windshield wiper fluid).

Nov 18, 2010 | 2003 BMW 325

2 Answers

2001 bmw fuel pump replacement

remove rear seat, it's just clipped in. remove fuel pump acces cover gasket, pull out fuel pump assembly. Hold off smoking till later. order online new pump for a third of the price. reinstall. bingo...done.

Jun 13, 2010 | 2001 BMW 325

1 Answer

Bmw diesel wont start in cold weather, i have


Jan 05, 2010 | 2001 BMW 5 Series

2 Answers

2.8 Diesel Pajero Cold start

Have replaced your glow plugs?They dont cost alot to replace,try this

Jun 22, 2009 | 2002 Toyota Land Cruiser

1 Answer

Not starting

if you got bad fuel it probably didn't have anything to do with weather conditions. the seal where the fuel nozzle goes into the fuel filler neck is pretty tight. i looked up the wiring diagrams for a 325i and i see that there are two fuses you might look at if you suspect you are having a fuel delivery problem. both are in the e-box under the hood, one serves the fuel injectors and the other the fuel pump relay. they are fuse 3 and fuse 5. if one of them is blown your car will not operate properly. replacing them might make it go again, but there is probably a reason it blew so i would not consider it a good fix or a reliable vehicle till you figure out why it blew. if they are both good you might check out the fuel filter. hope that helps

Jun 04, 2009 | 2002 BMW 3 Series

4 Answers

2003 Jetta diesel won't start in cold weather

We had this problem and replaced the ignition switch.

Jan 08, 2009 | 2000 Volkswagen Jetta TDI

Not finding what you are looking for?
2003 BMW 325 Logo

1,608 people viewed this question

Ask a Question

Usually answered in minutes!

Top BMW Experts

Anthony Jones
Anthony Jones

Level 2 Expert

128 Answers


Level 2 Expert

254 Answers


Level 2 Expert

281 Answers

Are you a BMW Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides