Faulty Fuel Gauge Nearly Causes Accident on M40!

[pjksutherland]

I've lived with my faulty fuel gauge for over a year now and it's always been OK as regardless of where the needle was the fuel warning light still came and gave me a good 15-20 miles of driving before it was totally out. I've run it down to the red enough times to trust the light on the gauge, if not the needle.... until today that was.

I was on the M40 driving back from Birmingham and had just passed Oxford. Despite not being reliable I do keep an eye on the gauge and the needle still said nearly half a tank, but I knew I had less than that as I'd done 170+ miles on the £45 fuel I put in this morning. A few seconds later the light came on, only this time I managed no more than a few hundred yards before the car died, and was totally out of petrol. In the fast lane of the M40, with my 2 year old son on board!

Fortunately the traffic was building up ahead of us and had slowed from about 90 to around 70 so when I stopped the cars behind were already in the process slowing down.

Unfortuantely I was going up the hill and had no momentum to carry me to the hard shoudler and only got as far as straddling the fast and middle lanes before I came to a complete stop - mainly because no one would let me across despite my having my hazards on! A couple of guys stopped the traffic on the motorway and pushed me across the the hard shoulder. All of this took no more than 30 seconds to a minute, but didn't stop people tooting and waving thier arms, as if I'd actually chosen to park on the m40 and take a little break!

Anyway, I carry a can of petrol so was on my way again in a couple of minutes and got home with no more dramas.

So, the question is... how can I fix my faulty fuel gauge before it kills me???

[DrGonzoPOW]

I have the same problem with mine. Will deffo keep a can of fuel in from now on! Glad your all safe

[pjksutherland]

Yeah, we're all good thanks! I won't go out without a can of fuel now either!! I've never carried one before in the 2 years I've had the car but chucked one in a few days ago for some reason - bloody good job too!

[e21-Mark]

buy a new sender unit

[pjksutherland]

buy a new sender unit

I'll have a look into getting one. Is it an easy enough DIY job?

[DrGonzoPOW]

Sender unit on mine was fine. The new E30 is fine, but the needle still jumps around like Muhammad Ali. Like yours, i just rely on the fuel light. But i guess if thats not coming on now (or al least not till its too late) then it may be the sender unit. I think i have a second hand E21 one in the workshop i could send you.
Its a matter of pulling out the back seats. The sender unit just screws into a hole in the fuel tank. Dead easy job but you will need a new sealing ring from BMW which is a couple of quid.

[Jeroen]

Glad you managed between half of the motorists not having a clue and the other half not paying any attention!

My gauge isn't exaclty spot on either but this sounds extreme and I'd replace the sender asap. No groud problems causing other gauges (especially for coolant temp) to jump? Known issue is different readings with rear screen heating on/off.

[e21mad]

Another shout to say glad you are all ok. I think we have another one for you know you drive an e21 when...XD

[pjksutherland]

Sender unit on mine was fine. The new E30 is fine, but the needle still jumps around like Muhammad Ali. Like yours, i just rely on the fuel light. But i guess if thats not coming on now (or al least not till its too late) then it may be the sender unit. I think i have a second hand E21 one in the workshop i could send you.
Its a matter of pulling out the back seats. The sender unit just screws into a hole in the fuel tank. Dead easy job but you will need a new sealing ring from BMW which is a couple of quid.

That'd be great if you've got one going spare - let me know how much you want for it.

Fitting sounds simple enough, and it's not bad timing as I have the rear seats out at the moment while I'm trying to modify the e30 leather rears to fit.

Glad you managed between half of the motorists not having a clue and the other half not paying any attention!

My gauge isn't exaclty spot on either but this sounds extreme and I'd replace the sender asap. No groud problems causing other gauges (especially for coolant temp) to jump? Known issue is different readings with rear screen heating on/off.

The other gauges are all working fine, so I'm going to put it down to the sender unit - with a little help from people on here hopefully I'll have a repalcement soon.

Thanks guys!

[e21-Mark]

Check the earths or, better still, run an extra one as old BMW gauges can be sensitive to poor earthing.

[DrGonzoPOW]

Sent you a pm mate. Get a sealing ring from BMW when you can. There only pennies. Its number 8 on this diagram
http://realoem.com/bmw/showparts.do?mod ... g=16&fg=05

[murran]

im also guilty of trusting just the fuel light. hmmmm.

light has always been reliable tho, coming on when theres about a gallon left. plus if you use your head about how much youve put in compared to far youve driven etc. usually i reset my mile counter each time i fill up too. a couple of times on the motorway i got to 50-60 miles on a tenner i got suspicious and decided to filled up..... but then within a mile the light came on!

[jimbob]

i have the same problem ran out yesterday but i was cutting it fine
i was a mile from my next petrol stop i had done 47 miles on a tenner

[pjksutherland]

Well, it seems there's a lot of us out there with the dodgy fuel gauges. Perhaps we should complain to watchdog and force BMW into doing a recall on all e21s to rectify the problem!

[murran]

170 miles on £45. thats not very good.
my run to drjims on sunday and to work and back yesterday..... ive driven nearly 90 miles on £20.