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BMW and MINI – Engine Will Not Start After Running Out of Fuel (Gas)

Jul 31 14

This answer is applicable for many BMWs in addition to the one listed below.

Q
Dear Otto,

I ran out of gas in my 2004 330ci.  After getting a couple gallons of gas and pouring it into the tank, the engine would not start.  I went and got two more gallons and added it, but the engine will still not start.  How much gas do I need to put in to get it started?  This seems really odd, since I can normally run it for 10, 20 or 30 miles after the reserve warning light comes on, before the “range” shows 0-miles.

A
We suspect that you may now have a failed fuel pump.  The fuel pump on later model BMWs and MINIs (as well as most other cars) is mounted inside the fuel tank and actually uses the fuel to cool and lubricate the pump.  Consistently running the fuel very low, will limit the amount of fresh cool fuel to keep the pump cool and lubricated …… accelerating the wear and shortening the life of the pump (this also applies to earlier models that have external in-line fuel pumps).  It’s likely that this last episode of running out of fuel was the “straw that broke the camel’s back”.  This ends up being fairly common, especially if the pump has a lot of miles of use or is often run with less than 1/4 fuel level.

We recommend replacing the fuel pump and this will likely cure your no-start issues.  Remember to replace the pump seal ring and have fresh hose clamps available to replace the original factory crimp clamps or rotten old hose clamps.  The Bentley Publishing repair manual (for the applicable BMW or MINI model), will cover the fuel pump replacement.

Fuel pump:

Hose clamps (search “hose clamp” after clicking link):

Bentley Publishing repair manuals:

 

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BMW or MINI Spark Plug Fouling – Misfire Fault Codes P0300, P0301, etc.

Jul 30 14

Are you having trouble with random or specific cylinder misfire fault codes?  These OBD-II fault codes can often be troublesome and difficult to track down and eliminate.  OBD-II fault codes for ignition misfires are commonly displayed as shown below:

P0300 – Random misfires; this is indicating that the engine management system is detecting misfires intermittently on multiple cylinders.

P0301 – Misfire on cylinder #1

P0302 – Misfire on cylinder #2

P0303 – Misfire on cylinder #3

P0304 – Misfire on cylinder #4

P0305 – Misfire on cylinder #5

P0306 – Misfire on cylinder #6

P0307 – Misfire on cylinder #7

P0308 – Misfire on cylinder #8

P03xx – Misfire on cylinder #xx, where the cylinder number is the last two digits of the code.

Today’s engines are designed to run within very tight parameters in order to satisfy emissions requirements.  Small variances in system functions can trigger fault codes through the OBD-II (On Board Diagnostics, v-2) monitoring system.  While there may be genuine problems within the engine management system,  keep in mind that short-trips, slow driving and prolonged idling can compound cylinder misfire issues, by not allowing the spark plugs to work at the higher temperatures required for “self-cleaning”.  In these cases, an otherwise properly functioning engine can generate misfire fault codes due to minor spark plug fouling.  Therefore, engines that see these types of conditions may need more frequent spark plug changes.

If you have fault codes for specific cylinder misfires, the first step is to swap the ignition coil assembly from the indicated cylinder, with the coil assembly from another cylinder.  Next, clear the fault codes and drive the vehicle.  If the fault code now comes up indicating the new cylinder location (the cylinder that the coil was moved to), you can assume that the coil assembly is at fault and replace the coil.  If the original fault code returns (same cylinder as the original misfire code), you can assume that the fault involves this specific cylinder.  The fault could be a fouled or worn spark plug, fuel injector problem, vacuum leak at this cylinder or a mechanical problem within the cylinder (leaking intake or exhaust valve, carbon build-up, etc.).

If the fault code returns to the original cylinder, after the coil swap and code clearing (as noted above), the next course of action should be to inspect the spark plug.  The plug may be worn or fouled, causing the misfire.  If the spark plug looks visibly fine (if not, replace it), swap it with another cylinder, similar to the coil swap.  Clear the fault codes and see if the fault returns.  In the same manner as the coil swap, test, if the fault code moves to the new cylinder, replace the spark plug (in fact, you should just replace them all, in this case).  If the code returns on the original cylinder, further testing and diagnosis will be required in order to determine if the fault is caused by the fuel injector, a vacuum leak or an issue within the cylinder.

If fault codes for random misfires are present, this could be fouling or worn spark plugs, arcing coil to spark plug connector boots or weak coils in addition to other engine management system faults.  If the spark plugs have more than a few thousand miles on them, it would be wise to pull them and have a look at the electrodes and the center electrode insulator for wear or a buildup of deposits.  If in-question, replace them, especially if the vehicle sees a lot of short trips and/or idling time.

Spark plugs and ignition coils:

Fault code readers and reset tools:

 

BMW E63 E64 6-Series LED Angel Eye Bulb Install – How To

Jul 24 14

This install guide covers installation of the LED upgrade Angel Eye (Halo) bulbs on the E63 and E64 6-series models 204 thru 2007 (645ci, 650i, M6 coupes and convertibles).

Click below for the install guide:
BMW E63 E64 LED Angel Eye Install

Click below for LED Angel Eye Bulb Kit:

 

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