My car wont start Please help ... E46 318i Auto N42 engine

zippy320

Well-known member
Hi Guys

Sad Sad sad news :(
I have an E46 318i Automatic with N42 engine.
Will try and explain the situation to you as best I can.

The vehicle turns over , as normal but wont start ,
I had the AA come over , the guy checked all the fuses and battery and concluded that its the fuel pump at fault.

When turning the key into position 2 I don't hear a buzz, I checked all fuses and non seem to be at fault. Generally from experience with the E30 not starting , if the fuel pump was pumping I would have a strong fuel smell near the engine, in this case there is non, which leads me to believe that its not pumping or getting power.

I attached one of those 12v light testing pens to the two contacts on the fuel pump fuse (the one in the glove box) and it does not light up. Should it light up?

I checked the fuse No.3 in the engine compartment and that also seems fine.

How do I test if its getting power?

How do I test the pump by attaching 12v to it to see if it would spin? (which pins do I use?)

How do I attach my 12v light to the wiring to see if it would light up?
(which pins do I use?)

How do I test the relay? The one in the glove box? Can I use my 12v light?

I have the car battery on charge now , as it did loose power while testing . Though at this point, im not even sure where to start.

Could low power from the battery also cause this?

Im not sure if this is related , but for the past week or two , I have been having issues with my fuel gauge giving incorrect readings, Iv been keeping the tank topped up at around half all this while but once it reaches the 1/4 points it cuts out.

Thanks for all your assistance , This is so depressing :cry:
 

Maljan

Active member
Not sure about the 318i but I can share a story about our E46 325i. Wife pulls car out of garage to get it washed. Afterwards she pulls it back in. Next day it wouldn't start.

It seems that there is a bug in the fuel injection firmware, or some sensor is clogged up from old age. What was happening was that the very short distance driven (less than 20m) really messes up the engine management. It was now flooding the car. Pulling out a spark plug confirmed this. It was smelling of unburned fuel.

The fix was a set of six shiny new not-cheap plugs. And a fully charged battery. You put the new plugs in and crank the starter. Give up. Try again. Repeat. Many, many times. Eventually it starts. Afterwards the electric seat did not adjust anymore, but I don't know if that is in any way related.

If you drove the car normally the day before, this is probably not your problem. But it might still be worth your while to pull out a plug and sniff it.
 

zippy320

Well-known member
Hi Guys

So I tried testing the plugs at the back seat once more,
there are two pins that Iv read ( two pins that are together) that I should use to test.

I Tested the one pin ( turned key , engine turns over) and the light does not light up .
Tested the other (Turned key , engine turns over ) and the light goes bright , but more of a pulsating , flashing bright.

Is it the pump?

Thanks for post Maljan , I did drive it normally yesterday, drove it , parked it , morning came and nothing.

Couldn't get any work done :(
 

Chucky

Active member
if the car was running fine before it wouldn't start, then just swap out the fuel pump and see, instead of going through all that.
Approach a friend, family member with another 318i ask if u can swap out the fuel pump to test.

its most likely the fuel pump that went poof!:sorry:
 

zippy320

Well-known member
Thanks for the reply Chucky , I dont have anyone to turn to with regards to these cars , All family and friends have newer F30s , 5s , 7s , x1s x5s and a 4 series Grand coup, Don't think I would want to risk removing their pumps even if it would fit hehe. I refuse to change my E46 .

I purchased a new pump today from Bosch , It should be delivered tomorrow.
I really hope its just the pump.

I was quoted 6300 for a new pump from BMW ! So I went the the Bosch part for R1350 from Diesel Electric. Wasn't to happy with one of those Chinese,Taiwanese branded pumps , so I went with the Bosch.

The pump that's in the car is of a VDO brand, still the original pump with hose and krimp seals on the pipes, Mileage on the car is 197800 kms now , so even if its not ( though I hope it is) im sure this would have failed sooner or later. Just lucky though that the car decided to "konk" out while parked in my garage. Still sucks not to have a car :(
Will see tomorrow , Wish me luck!
 

zippy320

Well-known member
Hi Guys!
An update , I received my new pump today, Had to dismantle the VDO pump and add this one to it. Fitted everything in, connected battery and it started on the first turn, I didnt even need to prime it :))

So excited and over the moon! Terrible feeling not being able to drive ones car. Thanks so much for all the assistance . It was the fuel pump.
The new pumps a Bosch unit, its smaller then the VDO but does its job.
Car feels a little smoother now, Not sure if its just me or my excitement haha but it does seem a little better.

Thanks again

zippy320 said:
Thanks for the reply Chucky , I dont have anyone to turn to with regards to these cars , All family and friends have newer F30s , 5s , 7s , x1s x5s and a 4 series Grand coup, Don't think I would want to risk removing their pumps even if it would fit hehe. I refuse to change my E46 .

I purchased a new pump today from Bosch , It should be delivered tomorrow.
I really hope its just the pump.

I was quoted 6300 for a new pump from BMW ! So I went the the Bosch part for R1350 from Diesel Electric. Wasn't to happy with one of those Chinese,Taiwanese branded pumps , so I went with the Bosch.

The pump that's in the car is of a VDO brand, still the original pump with hose and krimp seals on the pipes, Mileage on the car is 197800 kms now , so even if its not ( though I hope it is) im sure this would have failed sooner or later. Just lucky though that the car decided to "konk" out while parked in my garage. Still sucks not to have a car :(
Will see tomorrow , Wish me luck!
 

Marcobmw

New member
Hallo. Whille driving my bmw e46 318i last night, it just cut out and the eml light was on. The fuel pump aint geting power. Fuses is fine and I changed the fuel pump. Fuel pump still not geting power and eml light is on
 

Chucky

Active member
Hi Marcobmw

In your case it best to get the codes read; It could be a host of things that caused the car to cut out. Crank sensor, cam sensors VVT.
Diagnostics will narrow down the problem area.
 

zippy320

Well-known member
Hi Marco!

Check your fuel pump relay , Its a green relay behind the cubby box ( Glove box) You will have to go behind the plastic panels ( Black panels at the back ) Which means dismantleing the cubby box for easier access , If your cars fuel pump is not getting power this is one of the areas you should check , replace the pump relay first , This is a known problem for these cars ( I was told) .

Have a look at this , It might help you

http://www.pelicanparts.com/BMW/tec...l_Pump_Testing/108-FUEL-Fuel_Pump_Testing.htm

Regarding the EML ..... I don't know much about that light but it would be good to have your codes read , also check the condition of your Valvtronic unit , Is the engine rough? loosing power?

Marcobmw said:
Hallo. Whille driving my bmw e46 318i last night, it just cut out and the eml light was on. The fuel pump aint geting power. Fuses is fine and I changed the fuel pump. Fuel pump still not geting power and eml light is on
 
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