Today’s Ask MF comes from Bary:
>I have a 2005 cooper s, 32K miles … yesterday and today, when I turn on car, fuel gauge was on empty and yesterday it was half full. Today it showed 1/4, and then later in the day it was empty again. The computer says I have 0 miles left on the tank. Has anyone seem this happen? I have been searching forums and see no mention of
this.
We can only guess there is an issue with the fuel sensor located in the tank that runs both the computer at the gauge. However what exactly the issue is we’d have to defer to the experts. Or of course our illustrious readers. Sound off below.
<p>This happened on my 2008 R56. Just needed the fuel sensors replaced. After that I never had an issue.</p>
<p>This happened on my Oldsmobile, but it was due to certain fuel having additives that coated the fuel sensor and prevented it from correctly reading the level in the tank.</p>
<p>my classic mini with a 7 gallon tank shows empty with 4-5 gallons left. i guess that’s sir alex’s idea of a fuel reserve.</p>
<p>I had an issue with my 03 MCS where the fuel level would drop from full to zero while driving. And then go back to full. Turned out to be a bad electronics board in the dash, the service writer called it a “combi” board as I recall. Fixed under warranty. My car has factory nav, so my fuel guage setup is probably different than non-NAV cars.</p>
<p>I had a similar issue with my 06 Cooper. Occasionally the gas gauge would read empty. The first time it happened I thought someone had stolen my gas! 🙂 The problem was a faulty fuel sensor and the dealer replaced it under warranty. I haven’t had any problems since.</p>
<p>Wow, I just started having the exact same problem on my ’05 MCS last week (46,000 miles). Well, I’m glad that it’s not just me.</p>
<p>I had this problem once with my 2005 MCS. I found something about it on NAM, sorry I can’t find the link it was about 2006 when it happened. I remember having to do come type of ECU reset via the speedo. Never happened again.</p>
<p>I have the same problem 03 MCS. The gauge goes to empty then I turn the car back on later and it’s back to full.</p>
<p>First time it happened was 2 years ago twice and it stopped until recently.
I have 75000 miles so no warranty. Any idea how I could resolve this or check some wiring myself?</p>
<p>Thanks.</p>
<p>This is the NAM thread where I posted when it was happening to me. I don’t know what the real solution is and I haven’t seen the problem in a few months.
<a href="http://northamericanmotoring.com/forums/stock-problems-issues/118648-out-of-gas.html" rel="nofollow ugc">http://northamericanmotoring.com/forums/stock-problems-issues/118648-out-of-gas.html</a></p>
<p>I work a mini and we have had some do this not very many. you can try a cluster reset (kombi) by unhooking the battery for 20 mins. this has worked on some but not all. if this does not work it will need a fuel level sensor. there is a left and right sensor and it may only need one but you would need to have a dealer read faults or take them both out and ohm the sweep and watch for resistance changes. good luck.</p>
<p>I just remembered something. When it happened originally, I remember a service tech did some kind of ECU reset and fixed it.</p>
<p>Any suggestions?</p>
<p>Just yesterday I filled up my car and took a 30 minute trip on the autobahn back home. When I started my car an hour later it showed that my tank was empty. When I turned off my car and started it again, it showed the normal amount. I don’t know if my sensor is going bad or what…</p>
<p>Happens with my classic, but not with my MINI’s…yet.</p>
<p>Had this happen on my 06 Cooper…dealer fixed for free / warranty … don’t remember what they did</p>
<p>I had the same thing happen to my 05 MCS JCW. When I took it in, my SA told me there were over 200 fault codes that the thing had generated. Turns out the fuel sender was bad in one tank and questionable in the second. They replaced it under warranty. My mom has a 05 MCS Convertible JCW and had the same problem. My car is a Valentines Day build (Feb 14) and the convertible’s birthday is in May.</p>
<p>If you’d like any of the info I can garner from my tech notes provided upon checkout from the service, I’d be happy to send em to you.</p>
<p>It seems MF is not long for this world.</p>
<p>I had the same issue w/ my 05 MCSC (non-nav). They replaced the fuel tank sending unit under warranty. When I took the car in, I got the impression this was a fairly common problem (at least they seemed to know exactly what was going on when I told them what was happening.)</p>
<p>Kyle hit the nail on the head. Not exactly common, but not unheard of either. And yes, with the split tank, there are two senders to deal with.</p>
<p>Matt</p>
<p>that makes sense. I unhooked the battery for several minutes in the autumn to install rally lights. I haven’t had fuel gauge problems at all this summer.</p>
<p>Had the same trouble with my 03MCS now at about 35K mi. Full then next time I start it up… empty… another time – full – tough to reproduce the problem when I want to. What I’ve done is pull the fuel pump relay; clean the contacts; reinstall into the fuse block and usually that does the trick. So far good to go and since I’m out of warranty I’m not inclined to go replace the fuel sending unit.</p>
<p>I had the same problem with my R50 2002. It was only once in winter. Now is OK.</p>
<p>we want to know wat does faulty speedo gauge in a frieght liner motor mean it keeps on showing up on my truck in the front of steering wheel</p>