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I was at a conference for the last couple of days and started driving my beast out of the car park when it started miss firing.

Thought it could be damp as it has been cold here for a few days so tried more revs. Engine died. It felt like fuel starvation. The gauge read less than a quarter of a tank left and the range was 65 miles.

The AA (recovery) man came out to take a look but could not figure it out. Before calling for a recovery truck he thought he'd try putting some fuel in as diesel e39's have a secodary scavengeor fuel pump that can fail meaning the car exhibits similar behaviour to mine when only wneh the fuel is low.

One gallon later and the beast was working fine!

Anyone aware of a second pump on the M5? The AA man certainly had not seen it on any other petrol 5 series.

Max

PS. Total fuel put into the tank was 61 litres so the gauge was not mis reading.
 

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I had a similar problem a couple of weeks ago. A little less fuel in my tank, gauge read 45 miles. But I did exactly the same as you put a gallon in and away she went, good as new. It's strange because I've had it down as low as 18 miles, so I was wondering whether or not I'd got some "crap" in the fuel filter or something. Anyway in for a service next week, so I'll ask them to check.
 

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It is odd. I've been down to 0 miles before without a problem. I replaced the fuel filter approx. 15,000 miles ago and noticed it would have to big a very large piece if c*** to cause a blockage. The filter is the size of a small fire extinguisher!

I've just found a fuel tank diagram and it looks like there is a fuel scavenge pipe for one half of the tank. It could be that this pipe became blocked with some c*** and all the fuel happened to be on that particular side of the kidney shaped fuel tank.

It will be interesting to hear what your garage has to say.

Max
 

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Guys said it before and will say it always, our boys dont like running on small amounts of gas, just dont let the needle drop past 1/4 and ur good, I always leave mine in 1/2 never had the problem again.
 

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Dude: I think you ran out of gas.

The miles to go thing on the computer seems to be accurate to plus or minus 50 miles. I can park my car at night with 90 miles to go and no yellow light, and in the morning the yellow light will be on and I have 20 miles to go. As I drive the car the yellow light goes off and the miles to go go way up. The car has been like this since new.

I have pulled in the petrol station with 0 miles to go showing on the computer. The one and only time I ran out of gas - 1/2 mile from my local petrol station, I had 20 miles to go showing on the computer.

Steve
00 M5
 

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There are THREE fuel pumps in an M5 (and any BMW, I believe).

There is the main (full pressure, feed the injectors) fuel pump under the driver's floor (approximately). There is the fuel pump in the right hand fuel tank which pumps the fuel to the main pump. And, there is a siphon pump in the left hand tank that keeps the right hand tank (the one that the gas comes from to the engine) full, or the left tank empty after you have used about 10 gallons.

A failure of the siphon pump with show you out of gas too soon (at least mine did), so you should check the instrument display (it needs unlocking) and TEST # 4 (I think). It shows the gas (in liters) in the left tank, the right tank, and the total of both. At full, it doesn't show the last 5 liters.
 

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.

A failure of the siphon pump with show you out of gas too soon (at least mine did), so you should check the instrument display (it needs unlocking) and TEST # 4 (I think). It shows the gas (in liters) in the left tank, the right tank, and the total of both. At full, it doesn't show the last 5 liters.
Exactly, but test #6. From memory it shows 65L when full, even though we supposedly have 70L tanks.
Regards,
Jerry
 

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Discussion Starter #8
TC - I too thought I may be out of gas but full to the brim I only managed 61 litres which included the 5 litres from the recovery guy.

I think I might try letting it run down to the last quarter again (but this time carrying a spare can of fuel) and see what happens.

Max

PS. 61 litres costs me $136 in the UK!!
 

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Exactly, but test #6. From memory it shows 65L when full, even though we supposedly have 70L tanks.
Regards,
Jerry
That's right, and like I said, it doesn't show the last 5 liters when full. The full numbers are 34.0L/31.0L/65.0L or 31.0L/34.0L/65.0L (can't remeber which).
 

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TC - I too thought I may be out of gas but full to the brim I only managed 61 litres which included the 5 litres from the recovery guy.

I think I might try letting it run down to the last quarter again (but this time carrying a spare can of fuel) and see what happens.

Max

PS. 61 litres costs me $136 in the UK!!
You may want to look at the "hidden codes." Test # 14 (I think) will list up to 5 "hidden codes" on the console. If it shows (any one of the 5 listed) a D7 xx xxxx, then your siphon pump is bad (left tank sensor), and you probably have gas in the left tank that you can't use.
 

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Discussion Starter #11
jclyman

I'll give it a go. Should be down low enough by Monday.

Max
 

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jclyman

I'll give it a go. Should be down low enough by Monday.

Max
Good idea. Mine needed gas (as per the gauge, the fuel reserve light, and the Range ... Range said 4 miles, after very careful driving to try and get home).

I filled WAY UP, because I had only gotten 303 miles out of this tank (all freeway driving), and I should have gotten at least 350, probably 380.

It only took 15.5 gallons ... WHAT?

In talking on the phone with the mechanic, he asked if I had any "hidden codes" that started with a "D7?"

Test # 14 (I think that was the number) had ONE code (in a list for five). It was D7 81 0039.

I don't know what the 81 was and still don't, but figured out that the "0039" drops by one each time you start the car.

I think others here have may similar issues, but don't know it. My car had around 65,000 miles on it at the time.

Hope this helps.
 
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