Thanks for the reply...

My "new" approach after reading your reply is:

1. Inside the city, I guess it is not an issue b/c in the rare event (1% chance the siphon pump failure), I am always close to a gas station (or AAA etc.).
All it takes is a trip to the gas station with a gas can and the problem is solved.
This should be a very rare occurrence.

2. On long trips with gas stations far apart, I will just fill it when it is a tad above 1/4. Sure and safe way of staying out of trouble, given that the siphon pump is a potential Achilles heel of this (and many BMW) car. Life is too short to worry about this siphon pump thingy...

A counter-argument to this is that: a good test today on the siphon pump does not mean it will not fail tomorrow!

Anyway, I am happy with my solution above for long trips...

I agree with your thought for sure until the siphon jet is worked on. That can be "punted" down the road for a good while. If the main pump fails I would fix the siphon jet at the same time.

Case in point: after I already fixed wife's siphon jet at 131,000 I didn't yet fix mine at 150,000+ because I knew it was working (until It didn't). I always wait for my low fuel light.

Sure enough my o-ring blows and I stall with about 50 mile to empty.

I knew it was siphon jet before I even put in 2 gal to get home.

That is quite true hence "periodic" test and also I recommend preventive maintenance on the siphon jet at 120,000 miles or 4000 hours. One zip tie will prevent the failure.


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@cn90,

Thanks for the heads up :thumbup:...... it looked identical to the one I pulled out.

i'll keep everyone posted when it fails......:(

Hi,

I have BMW 2002 X5 4.6is. My X5 wont stay ON just idle sputter and dies since the car hit 1/4 gas tank. Is this related to siphon pump issue. My car ran fine before till hit fuel gauge hit 1/4 tank. I suspect the fuel pump but when i release the fuel line from engine squirt gas. Pls help

HOLY COW i added the 2 gallon of GAS and started right away it has to be siphon O-RING issue. From now i wont let go down pass 1/4 of gas till i fix this issues. Thx for all the info!

possible fuel pump?
 

It's for sure siphon jet. Confirmation is pulling up test six: if at about 30L total the right side will start to drop below 1L of gas. (Don't fret too much there is about 3.5L below zero).

Everybody should learn their baseline right side. When things are running properly, the left side should go to zero before the right side drops below the baseline (which is usually about 1.4L)