Tank doesn't seem to go empty

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calor
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Wed Apr 01, 2020 11:53 am

Whenever I go tank, even when the tank (indicator) says it's real close to empty, I can never get more than 40L in the tank. On the wiki I read that E30s are supposed to have a 55L fuel tank by default. I'm afraid of running the car completely dry, I believe it's quite bad for your fuel system to run all the old shit at the bottom of your tank through the system. Maybe I'm mistaken.

Any hints?
DanThe
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Fri Apr 03, 2020 9:15 am

Put a 5l tin of fuel in the boot then run it dry, you will be surprised at how much the needle drops
e30-EVN
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Fri Apr 03, 2020 9:26 am

DanThe wrote:
Fri Apr 03, 2020 9:15 am
Put a 5l tin of fuel in the boot then run it dry, you will be surprised at how much the needle drops
This!
Mine drops off the gauge lol
A 2 door e30 with 8 cylinders, what could be better winkeye :D
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Brianmoooore
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Fri Apr 03, 2020 11:27 am

calor wrote:
Wed Apr 01, 2020 11:53 am
Whenever I go tank, even when the tank (indicator) says it's real close to empty
The mistake you're making is only including the painted part of the dial. It includes the part that eventually lights up, and this won't happen until the needle is well into this segment.
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flybynite
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Fri Apr 03, 2020 11:46 am

For many years mine had the opposite problem, it had the Alpina aux tank in it that is not connected to the gauge. Once full the needle never moved off the top for ages.

Once the vent pipe got kinked and it must have airlocked. Gauge dropped to half and went back to full again. Took a while to work that one out :mad:

Never really worked out how much that car was meant to hold.
Kalimsnor
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Mon Apr 06, 2020 9:38 am

I have a can ready to fill up with gas and try this, but everywhere I read online they say it's terribly bad for your car to run it completely dry. Aren't you guys worried about that?
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flybynite
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Mon Apr 06, 2020 9:59 am

No need to run it completely dry, just see if it goes lower.

As Brian says are you letting it go into the Lit area? The lower mark says R for Refuel not E for empty.

Empty is bottom of the Low fuel warning light, Seemed to be fairly accurate on both of mine when they were on the road.

I used to work on getting about 30 miles to empty from when the light came on, seemed to be right
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Brianmoooore
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Mon Apr 06, 2020 10:05 am

Kalimsnor wrote:
Mon Apr 06, 2020 9:38 am
I read online they say it's terribly bad for your car to run it completely dry.
Based on what evidence? It's not a good idea to do it after every time you fill the tank, as sucking air will wear the pump, but very occasionally isn't going to do any harm.
The fuel pump pick up filter sits in a bowl which is continuously replenished with filtered fuel, returned from the engine, so is unlikely to pick up much debris anyway.
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paultv
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Mon Apr 06, 2020 10:13 am

This is also why you should change the fuel filter regularly.

Paul :-)
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https://bmwe30cabriolet-wdm.blogspot.com/
DanThe
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Mon Apr 06, 2020 6:49 pm

If you run it dry the car will stop, which could be bad, depending on whereabouts you are at that time :)
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Brianmoooore
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Mon Apr 06, 2020 7:06 pm

Low fuel lamp will light at least 20 miles before that.
coopman
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Tue Apr 07, 2020 12:59 am

Brianmoooore wrote:
Mon Apr 06, 2020 10:05 am
Kalimsnor wrote:
Mon Apr 06, 2020 9:38 am
I read online they say it's terribly bad for your car to run it completely dry.
Based on what evidence? It's not a good idea to do it after every time you fill the tank, as sucking air will wear the pump, but very occasionally isn't going to do any harm.
The fuel pump pick up filter sits in a bowl which is continuously replenished with filtered fuel, returned from the engine, so is unlikely to pick up much debris anyway.
Maintaining higher levels of fuel also helps protect the fuel tank from corrosion (less room for condensation)?
Kalimsnor
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Sun Apr 12, 2020 5:29 pm

You guys are completely right, thanks. Turns out the tank does go a lot further down than I thought. 55L it is!
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