If you want to do something while you are waiting you can try rapping on the tank with a 2x4 or something while someone is cranking the engine, sometimes will get the pump going again! ;)

I haven't figured out if 1) the pump is dead,2) the filter is clogged>keeping the pump from working (gasoline isn't compressible), or what. In your thread praising the Delphi pump (at first), I stated that I'm unsure about which pump to get.

I'll rap on the pump tomorrow, when I pull it out and test it in a bucket of gas. That'll be the final test for the pump, but regardless, I'll be getting a new one.

I'm on the fence about getting a new filter (it'll be hell on my poor old body to crawl underneath to change it), so we'll see how things go after a new pump assembly is installed. The PO replaced the fuel pressure regulator about 3k miles agao, while he was preparing it to swap to me), but nobody knows the age of the filter, itself.

The pump has a relief valve so the filter being clogged will not stop it from running. You would think if someone went through the work (it is a bit of a job) to change the regulator they would have changed the filter as well but you never know.

I was hoping that it's unlikely that the filter would get completely plugged, suddenly. My X5 has never shown a stumble on starting, nor has there ever been a long crank, even with a low battery.

I asked my neighbor why he didn't replace both the filter and regulator at once, but he said it didn't seem to need both. of course, he's a Subaru, Kia, Jeep, and Dodge Ram fan, so what would he know. hahaha

Usually and hopefully it is just that.

I've gone Pierburg and Bosch on MB's and other BMW's and they were always good.

For the E53 you can change just the pump or the pump/float assy, it just gets a bit fiddly replacing the pump. Sometimes the old plastic breaks, sometimes the wiring insulation is all gone and you risk shorts.

Also, one gotcha for me was centering the float on the divot at the fuel tank floor. Went through 3 broken left side floats before a tech with experience showed me the problem. Suggest doing that job with as close to empty a fuel tank as possible.

Fuel filter has a fuel pressure regulator on the E53's. Have not really looked if there are other FPR's in the fuel system besides the ones on the fuel filter.

The fuel filter is huge on the e53. It's usually good for life or 3-400,000 miles. The o-ring on the FPR is what will fail first. When that happens the symptom is hard starts.

If you have the seat up for access to the pump top you can use the percussive maintenance yourself. A rubber mallet white in the seated position.

I forgot if you're 3.0 or 4.4. The 3.0 will prime the pump at key on. Most 4.4 will wait until start to turn on the pump due to the auto crank feature.

As mentioned if the filler was plugged the fpr will just open at 50 psi and send everything back to the left tank.

MTBF on a fuel pump using E10 gas is 5000 hours. On both mine and wife's original pump that was crazy close: within 3-4%. Look at your average mph and multiply by 5000. Eg 27*5000=135000. If your odometer is over that number your pump is overdue for replacement.

If your siphon jet is still original definitely time to check it's o-ring.

I would take a jump pack or M12 battery and hotwire the pump to see if it runs with power directly applied. Rap on it at the same time. If it spins, start the car just to get it some exercise and check codes.

I had issues with the pump being a different size when i replaced just the pump and had to modify the frame.

When changing the whole assembly with discount model, the float wasn't at the same height and it changed the tank fill values.

It's imperative the foot gets into the notch in the bottom of the tank as mentioned.

The gasket on the pump assembly usually falls off during removal. It must go on the pump not the tank during assembly. I wet it with a dab of gas with a gloved finger to ease install.

It's one of the easier jobs. 3/10 difficulty hardest part is battling the seat that wants to fall on you. I opted to detach the middle seatbelt by the third time i did this job.

Fold the float up to remove vs. attempt to tip the pump sideways.


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I forgot to mention that I also used my multimeter to test the motor windings, It showed OL-open loop, which I believe means there is a break in the circuit, and the motor is faulty and will not work. So, time to order one.

Again, my X5 is a 3.0i, and there was no "prime" either at the inspection station, nor now, under test. I guess I won't have to use stating fluid, sprayed into the intake boot, to see if it'll fire up, or even try to (my usual test for ignition spark when I don't want to take out plugs or use a spark checker tool...which I can't seem to locate, of course). Following 80stech's advice, I won't be testing the pump outside the tank...I have a reputation as both accident prone, and a bit of a fire hazard (BBQ starting incidents).

From what you guys are saying, you've bought replacement pump motors and had trouble with installing them into the old housing, or had to modify them for fit??? So, I will get a Hella pump assembly, to drop straight in, and because it is half the price of the Delphi, and a third (or less than the BMW OEM assembly's price). Beggars can't be choosers!

indecision
 

Before I order a pump assembly, I was looking over the possible choices, and saw that I overlooked a pump assemble by Meyle, on ECS Tuning, for $182 vs the Hella assembly for $138 on RockAuto. Would the Meyle be better for $44 more, any opinions?

The Hella has a 12-mo guarantee, but I can't find the warranty on the ECS site, for the Meyle assembly.

ESC lifetime exchange i think


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