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BMW 3 Series E46 - My car won't start - Mark1976

Hi John

My car started to be hard to start a couple of weeks ago. When it was running it was fine no missing or lose of power. Then this weekend it would'nt start at all. There is no smoke comming out the exhaust but there is fuel getting up past the the filter. To start with I thought is was heater plugs but because there is no smoke I now think its my pump but I thought there should be no real warning with it like being hard to start, I thought it should either go or not have u any advise for me.

Many Thanks


BMW 3 Series E46 - My car won't start - Shugs

This starting problem is common with E46 diesels and mine behaved exactly like yours. The first thing to check is the relay that switches the low pressure fuel pump. When you turn on the ignition, you should hear a satisfying 'clonk' from a relay behind the glovebox, followed by a slight thrum from the fuel pump. The relays will probably be as shown in this illustration, which is for my 2004 E46 320d Touring: bmwfans.info/parts/catalog/E46/Touring/Europe/320d.../ . In my case, the BMW dealer wanted a day's work to diagnose the problem - I bought the relevant relay (which is a light green colour, BMW Part No 6136-8 373 700) for £6 and put it in myself, then no problems at all, so a whole load of cash saved. Reading threads on BMW forums, there are many people who have been skinned alive by dealers changing pumps, filters etc, before finding out that it was the £6 relay all along. Locating the correct relay was for me a matter of substituting each one in turn until the fuel pump ran - I'm sorry that I can't remember which one is which. To access the relays you have to remove the glovebox assembly, which is not as bad as it sounds - quite easy in fact.

If you can hear the fuel pump running, then it's something else, but the relay is the most likely cause of your problem.

BMW 3 Series E46 - My car won't start - Mark1976

John thanks alot I will do that I was starting to panick thinking I needed a knew pump, might still do but I will eliminate the relays first. That makes me feel more at ease, I think I will get rid of it once this was fixed little things are starting to go wrong and its only time before something major goes wrong.

BMW 3 Series E46 - My car won't start - Avant

Moved to Technical.


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